tag:blogger.com,1999:blog-8384118971406737172024-02-26T23:05:14.626+05:30Marine NotesMarine Noteshttp://www.blogger.com/profile/14270820931606062583noreply@blogger.comBlogger1023125tag:blogger.com,1999:blog-838411897140673717.post-11362892817395488012013-08-03T14:40:00.000+05:302013-08-03T14:40:22.263+05:30MMD E-Pariksha Online Exam Mode<center><!-- Begin of AdsforIndians AdNetwork -->
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</center></div>mmanindarkumarhttp://www.blogger.com/profile/05741314530132604499noreply@blogger.com1tag:blogger.com,1999:blog-838411897140673717.post-65296705258379772872013-03-23T09:24:00.001+05:302013-07-27T16:42:15.123+05:30Turbo charging and its operation<div dir="ltr" style="text-align: left;" trbidi="on">
<div class="" style="color: black; font-family: Arial; font-size: 16pt; font-weight: bold; line-height: 38pt; margin: 24pt 0cm 12pt; text-indent: 0cm;">
<span lang="EN-GB">Turbo charging</span><span lang="EN-GB"></span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 12pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Arial;">A turbo charger (sometimes called a turbo blower) can be fitted to both two and four stroke engines to increase the volumetric efficiency and thus their power output.</span></div>
<div class="" style="color: black; font-family: 'Arial Narrow'; font-size: 16pt; font-weight: bold; line-height: 16pt; margin: 12pt 0cm 6pt;">
<span lang="EN-GB" style="font-family: Arial;">Advantages</span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 12pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Arial;">The advantage of a turbo charger is that fuel consumption is lower than that of a normally aspirated engine of the same power output.</span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 12pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Arial;">In addition, the turbo charger utilises the exhaust gases of the engine so no power from the engine is required to drive it.</span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 12pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Arial;">The turbo charger causes a larger mass of air into the cylinder to that of a same cubic capacity normally aspirated engine. This allows for a proportional increase in the amount of fuel that can be injected and burnt in the cylinder thereby providing an increase in the power output of the engine. </span></div>
<div class="" style="color: black; font-family: 'Arial Narrow'; font-size: 18pt; font-weight: bold; line-height: 20pt; margin: 20pt 0cm 8pt;">
<span lang="EN-GB" style="font-family: Arial;">Components of a turbo charger</span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 12pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Arial;">The components of a turbo charger are shown below.</span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; margin: 0cm 0cm 12pt; text-indent: 70.9pt;">
<b><i><span lang="EN-GB" style="font-family: Arial;"><img border="0" src="http://www.splashmaritime.com.au/Marops/data/text/Med3tex/Engpropmed2_files/image016.jpg" height="286" width="354" /></span></i></b></div>
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<b><i></i></b><b><i><span lang="EN-GB" style="font-family: Arial;">Turbo charger</span></i></b></div>
<b style="color: black; font-family: 'Times New Roman'; font-size: medium;"><i><span lang="EN-GB" style="font-family: Arial; font-size: 12pt;"><br clear="all" /></span></i></b><span style="color: black; font-family: 'Times New Roman'; font-size: small;"></span>
<div align="center" class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 12pt; text-align: center; text-indent: 70.9pt;">
<br /></div>
<table border="0" cellpadding="0" cellspacing="0" class="" style="border-collapse: collapse; font-family: 'Times New Roman'; margin-left: 12.5pt;"><tbody>
<tr> <td style="padding: 0cm 5.4pt; width: 99.25pt;" valign="top" width="132"><div class="" style="font-family: 'Times New Roman'; font-size: 10pt; margin: 0cm 0cm 0.0001pt;">
<span lang="EN-GB" style="font-family: Arial; font-size: 12pt;">Rotor assembly</span></div>
</td><td style="padding: 0cm 5.4pt; width: 338.45pt;" valign="top" width="451"><div class="" style="font-family: 'Times New Roman'; font-size: 10pt; margin: 0cm 0cm 0.0001pt;">
<span lang="EN-GB" style="font-family: Arial; font-size: 12pt;">It has a rotor shaft which has exhaust gas turbine blades on one end and air compressor blades on the other end.</span></div>
<div class="" style="font-family: 'Times New Roman'; font-size: 10pt; margin: 0cm 0cm 0.0001pt;">
<br /></div>
</td></tr>
<tr><td style="padding: 0cm 5.4pt; width: 99.25pt;" valign="top" width="132"><div class="" style="font-family: 'Times New Roman'; font-size: 10pt; margin: 0cm 0cm 0.0001pt;">
<span lang="EN-GB" style="font-family: Arial; font-size: 12pt;">Casings</span></div>
</td><td style="padding: 0cm 5.4pt; width: 338.45pt;" valign="top" width="451"><div class="" style="font-family: 'Times New Roman'; font-size: 10pt; margin: 0cm 0cm 0.0001pt;">
<span lang="EN-GB" style="font-family: Arial; font-size: 12pt;">The exhaust gas turbine blades are housed in a casing which is attached to the exhaust manifold and to the exhaust pipe. Some casings are fresh water cooled to minimise the heat radiated out into the engine space. This allows for a cooler engine space, cooler air entering the engine air intake and therefore more power again. A nozzle ring is fitted inside the casing to direct the flow of exhaust gases to the turbine blades.</span></div>
<div class="" style="font-family: 'Times New Roman'; font-size: 10pt; margin: 0cm 0cm 0.0001pt;">
<span lang="EN-GB" style="font-family: Arial; font-size: 12pt;">The air compressor blades are also housed in a casing which has an air cleaner on the intake side and is connected to the intake manifold on the discharge side. Where an engine is after cooled, the discharge side is connected to the after cooler which is then connected to the intake manifold.</span></div>
<div class="" style="font-family: 'Times New Roman'; font-size: 10pt; margin: 0cm 0cm 0.0001pt;">
<span lang="EN-GB" style="font-family: Arial; font-size: 12pt;">Both the above casings are attached to a centre casing which contains the bearings, seals and method of lubrication.</span></div>
<div class="" style="font-family: 'Times New Roman'; font-size: 10pt; margin: 0cm 0cm 0.0001pt;">
<br /></div>
</td></tr>
<tr><td style="padding: 0cm 5.4pt; width: 99.25pt;" valign="top" width="132"><div class="" style="font-family: 'Times New Roman'; font-size: 10pt; margin: 0cm 0cm 0.0001pt;">
<span lang="EN-GB" style="font-family: Arial; font-size: 12pt;">Bearings and lubrication</span></div>
</td><td style="padding: 0cm 5.4pt; width: 338.45pt;" valign="top" width="451"><div class="" style="font-family: 'Times New Roman'; font-size: 10pt; margin: 0cm 0cm 0.0001pt;">
<span lang="EN-GB" style="font-family: Arial; font-size: 12pt;">The shaft may rotate in white metal bearings which can be lubricated from the engine driven oil pump. This method of lubrication also allows the oil to remove some of the heat in the turbo charger. One bearing locates the shaft and takes the small residual <span class="">thrust,</span> the other bearing allows the shaft to move longitudinally to accommodate the differential thermal expansion of casings and shafting.</span></div>
<div class="" style="font-family: 'Times New Roman'; font-size: 10pt; margin: 0cm 0cm 0.0001pt;">
<span lang="EN-GB" style="font-family: Arial; font-size: 12pt;">Alternatively, the smaller turbo chargers usually incorporate a ball bearing for positioning at the compressor <span class="">end and</span> a roller bearing to accommodate axial expansion at the turbine end of the rotor shaft. The bearings may have their own reservoir which forms part of the turbo charger. These reservoirs usually have round oil level sight glasses with two horizontal lines marked to indicate the high and low levels. Seals are fitted to retain the oil.</span></div>
</td></tr>
</tbody></table>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: 10pt; margin: 0cm 0cm 0.0001pt;">
<br /></div>
<span lang="EN-GB" style="color: black; font-family: 'Times New Roman'; font-size: 10pt;"><br clear="all" /> </span><span style="color: black; font-family: 'Times New Roman'; font-size: small;"></span><br />
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: 10pt; margin: 0cm 0cm 0.0001pt;">
<b><span lang="EN-GB" style="font-family: Arial; font-size: 16pt;">Operation of the turbo charger on a diesel engine</span></b></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: 10pt; margin: 0cm 0cm 0.0001pt;">
<br /></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 12pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Arial;">In a four stroke engine, exhaust gases flow from each cylinder into the exhaust manifold and then past the turbine blades of the turbo charger. With the engine running at full speed, the turbo charger can obtain speeds up to 100,000 revolutions per minute (rpm).</span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 12pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Arial;">The air compressor blades will revolve at the same speed. Air is drawn through the air cleaner and forced under pressure into the intake manifold. When the inlet valve opens on the induction stroke, with the piston descending in its cylinder, air is forced into the cylinder.</span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 12pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Arial;">It is necessary to reduce the turbo charger speed in stages or slowly for two reasons:</span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 12pt; text-indent: 70.9pt;">
<b><span lang="EN-GB" style="font-family: Arial;">1.<span style="font-family: 'Times New Roman'; font-size: 7pt; font-weight: normal; line-height: normal;"> </span></span></b><span dir="LTR"><span lang="EN-GB" style="font-family: Arial;">If the engine speed is reduced from full engine speed to stop quickly and the bearings of the turbo charger are lubricated by the main engine driven lubricating oil pump, the engine, on stopping, will cease to supply the lubricating oil to the turbo charger bearings. Because of its high speed, it will take some time for the turbo charger to come to rest and the bearings could be damaged.</span></span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 12pt; text-indent: 70.9pt;">
<b><span lang="EN-GB" style="font-family: Arial;">2.<span style="font-family: 'Times New Roman'; font-size: 7pt; font-weight: normal; line-height: normal;"> </span></span></b><span dir="LTR"><span lang="EN-GB" style="font-family: Arial;">The exhaust gas side of the turbo charger operates at a very high temperature. It is preferable to reduce the temperature gradually rather than quickly to prevent unequal contraction of the turbo charger parts as it slows down.</span></span></div>
<div class="" style="color: black; font-family: 'Arial Narrow'; font-size: 16pt; font-weight: bold; line-height: 16pt; margin: 12pt 0cm 6pt;">
<span lang="EN-GB" style="font-family: Arial;">Monitoring the performance</span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 12pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Arial;">Normally, as part of the purchase of a new engine, the engine distributor or dealer will do an installation and pre-run check. The following will be recorded:</span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 4pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Symbol;">·<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;"> </span></span><span dir="LTR"><span lang="EN-GB" style="font-family: Arial;">The speed of the turbo charger at a nominated engine speed.</span></span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 4pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Symbol;">·<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;"> </span></span><span dir="LTR"><span lang="EN-GB" style="font-family: Arial;">Air flow in.</span></span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 4pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Symbol;">·<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;"> </span></span><span dir="LTR"><span lang="EN-GB" style="font-family: Arial;">Air flow out.</span></span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 4pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Symbol;">·<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;"> </span></span><span dir="LTR"><span lang="EN-GB" style="font-family: Arial;">Air pressure after the compressor blades.</span></span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 12pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Symbol;">·<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;"> </span></span><span dir="LTR"><span lang="EN-GB" style="font-family: Arial;">Exhaust gas flow.</span></span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 12pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Arial;">The flow of air going into the turbo charger is important. The air is taken from the engine room so sufficient ventilation to the engine room is required to ensure there is enough for the engine as well as cooling the engine room.</span></div>
<span lang="EN-GB" style="color: black; font-family: Arial; font-size: 12pt;"><br clear="all" /></span><span style="color: black; font-family: 'Times New Roman'; font-size: small;"></span>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 12pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Arial;">The exhaust gas flow is also important. It ensures the installation of the exhaust piping is within limits and not restricting the performance of the engine.</span></div>
<div class="" style="color: black; font-family: 'Times New Roman'; font-size: medium; line-height: 14pt; margin: 0cm 0cm 12pt; text-indent: 70.9pt;">
<span lang="EN-GB" style="font-family: Arial;">As the above is recorded, checks can always be carried out and readings compared with the initial ones.</span></div>
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</center></div>Marine Noteshttp://www.blogger.com/profile/14270820931606062583noreply@blogger.com1tag:blogger.com,1999:blog-838411897140673717.post-40630195519856988592013-03-23T09:21:00.001+05:302013-03-23T09:21:37.237+05:30Timing a fuel injection pump<div dir="ltr"><p class="" style="margin:0cm 0cm 12pt;line-height:38pt;font-size:16pt;font-family:'Arial Narrow';font-weight:bold;color:rgb(0,0,0);text-indent:7.1pt"><span lang="EN-GB" style="font-family:Arial">Timing a fuel injection pump</span><span lang="EN-GB" style="font-family:Arial"></span></p> <p class="" style="margin:12pt 0cm 6pt;line-height:16pt;font-size:16pt;font-family:'Arial Narrow';font-weight:bold;color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial">Early injection</span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial">If the injection occurs too early on the compression stroke, it will result in high peak pressures. This will subject the engine to unsafe stresses caused by the tendency of the pressure to reverse the rotation of the engine and evidence by excessive detonation which is known as diesel knock.</span></p> <p class="" style="margin:12pt 0cm 6pt;line-height:16pt;font-size:16pt;font-family:'Arial Narrow';font-weight:bold;color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial">Late injection</span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial">Retarded injection or late burning gives incomplete combustion causing too low a power output and overheating.</span></p><p class="" style="margin:12pt 0cm 6pt;line-height:16pt;font-size:16pt;font-family:'Arial Narrow';font-weight:bold;color:rgb(0,0,0)"> <span lang="EN-GB" style="font-family:Arial">Timing instructions</span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial">It will be necessary to follow the <span class="">manufacturers</span> instructions in the Owners Manual to time the fuel pump to the engine as different methods are employed.</span></p> <p class="" style="margin:12pt 0cm 6pt;line-height:16pt;font-size:16pt;font-family:'Arial Narrow';font-weight:bold;color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial">Timing principle</span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial">The principle is that fuel injection commences on the compression stroke just before top dead <span class="">center</span>. With a four stroke, the piston also comes up to top dead <span class="">center</span> on the exhaust stroke. Make sure it is on the compression stroke.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">As with timing inlet and exhaust valves, the fuel injection pump must be timed to inject fuel at the correct angle on the compression stroke. This means that the gear driven shaft to the pump must also be lined up in the gear wheel train. Otherwise, difficulty might be experienced in lining up the holes in the drive coupling.</span></p> <p class="" style="margin:12pt 0cm 6pt;line-height:16pt;font-size:16pt;font-family:'Arial Narrow';font-weight:bold;color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial">Timing engine to pump</span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial">The flywheel is usually marked with a TDC and with an injection mark that is before the TDC mark when turning the engine over in the direction of rotation. Turn the engine over in the direction of rotation until its number 1 cylinder is on the compression stroke and the injection mark is lined up.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">The fuel injection pump must also be lined up on number 1 element or port at the commencement of injection. The Owners Manual will identify the position of the lining up marks as brands of pumps differ. When the <span class="">lining up marks on the pump correspond</span>, the drive couplings can be bolted together.</span></p> <b style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"><span lang="EN-GB" style="font-size:16pt;font-family:Arial"><br clear="all" style></span></b><span style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"></span><p class="" style="margin:12pt 0cm 6pt;line-height:16pt;font-size:16pt;font-family:'Arial Narrow';font-weight:bold;color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial"> </span></p><p class="" style="margin:12pt 0cm 6pt;line-height:16pt;font-size:16pt;font-family:'Arial Narrow';font-weight:bold;color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial">Alternative method of timing</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">To make it easier still, some manufacturers make provision for locking the fuel injector pump shaft at a position <b>corresponding to</b> <b>top dead <span class="">center</span></b> for number 1 cylinder. A further pin is then located in a hole in the camshaft timing gear that is top dead <span class="">center</span> for number 1 cylinder. The drive couplings can then be bolted together and the pins removed.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">As the pin is located in a hole in the camshaft, it can only be on the compression stroke on a four stroke engine.</span></p> <p class="" style="margin:12pt 0cm 6pt;line-height:16pt;font-size:16pt;font-family:'Arial Narrow';font-weight:bold;color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial">Checking the timing of a fuel pump</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">The timing may be checked as follows:</span></p> <p class="" style="margin:0cm 0cm 12pt;text-indent:70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><b><span lang="EN-GB" style="font-family:Arial">1.<span style="font-weight:normal;font-size:7pt;line-height:normal;font-family:'Times New Roman'"> </span></span></b><span dir="LTR"><span lang="EN-GB" style="font-family:Arial">Remove the delivery valve and spring from number 1 element in the fuel injection pump.</span></span></p> <p class="" style="margin:0cm 0cm 12pt;text-indent:70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><b><span lang="EN-GB" style="font-family:Arial">2.<span style="font-weight:normal;font-size:7pt;line-height:normal;font-family:'Times New Roman'"> </span></span></b><span dir="LTR"><span lang="EN-GB" style="font-family:Arial">Open the throttle to the full position. <i>(If the throttle is left at the stop position, the slot in the plunger will be in line with the spill port and no fuel will be delivered.)</i></span></span></p> <p class="" style="margin:0cm 0cm 12pt;text-indent:70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><b><span lang="EN-GB" style="font-family:Arial">3.<span style="font-weight:normal;font-size:7pt;line-height:normal;font-family:'Times New Roman'"> </span></span></b><span dir="LTR"><span lang="EN-GB" style="font-family:Arial">Rotate the engine in its operating direction until number 1 cylinder is on the compression stroke. Keep rotating the engine slowly and when the mark on the flywheel, indicating the start of injection is lined up with the timing indicator mark, fuel will immediately start to rise from where the delivery valve was removed. <i>(This will mean the top of the plunger has just covered the inlet and spill ports and injection is starting).</i><i></i></span></span></p> <p class="" style="margin:0cm 0cm 12pt;text-indent:70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><b><span lang="EN-GB" style="font-family:Arial">4.<span style="font-weight:normal;font-size:7pt;line-height:normal;font-family:'Times New Roman'"> </span></span></b><span dir="LTR"><span lang="EN-GB" style="font-family:Arial">If fuel starts to rise before or after the timing marks are in line, the fuel pump timing is out and will have to be adjusted.</span></span></p> <p class="" style="margin:12pt 0cm 6pt;line-height:16pt;font-size:16pt;font-family:'Arial Narrow';font-weight:bold;color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial">Detroit</span><span lang="EN-GB" style="font-family:Arial"> Diesel unit injector</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial"> On a Detroit Diesel, the cam that actuates the unit injector is on the same shaft as the cams for the exhaust valves. If the exhaust valves are correctly timed, that is they open and close at the correct angles, then the unit injector timing must be correct. It is then only a matter of adjusting the unit injector follower to get the correct height in relation to the unit injector body. A special gauge is supplied for this purpose.</span></p> <p class="" style="margin:12pt 0cm 6pt;line-height:16pt;font-size:16pt;font-family:'Arial Narrow';font-weight:bold;color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial">Cummins PT injector</span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial">On the Cummins PT system, it is only a matter of setting the clearance between the rocker arm and the injector.</span></p><b style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"></b><div> <br></div>-- <br><div dir="ltr"><div style="text-align:center"><font size="1"><u><b><font color="#ff0000">M</font><a href="http://marinenotes.blogspot.in" style="color:rgb(255,0,0)" target="_blank"><font>arineN</font>otes.blogspot.in</a></b></u></font></div> <div style="text-align:center"><div><img src="http://i844.photobucket.com/albums/ab3/283928/b_dl.gif"><a href="http://marinenotesonline.blogspot.in/p/buy-marine-notes.html" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/b_buy.gif"></a><font color="#ff0000"><a href="http://marinenotesonline.blogspot.com/p/marine-notes-online-order-form-var.html" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/WriteDocument_zps380e535b.png"></a><a href="mailto:marinenotesonline@gmail.com" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/1310735291_icon-email_zps9ea76f56.jpg"></a><br> Free Download <b><span style="color:rgb(0,0,255)">&</span></b> Buy Online via Secure Paypal </font><font color="#0000ff">or</font><font color="#ff0000"> Fill Order Form.</font></div><div><b style="color:rgb(0,0,255)"><font size="1"><a href="http://marinenotesonline.blogspot.in/" target="_blank">Marine Notes Online</a></font></b></div> <br></div></div> </div> <div class="blogger-post-footer"><script type="text/javascript"><!--
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The valve train is geared or has a chain drive with sprockets on the camshaft and crankshaft.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">Any slight variation from the correct timing setting will result in loss of power and overheating. Any large variation and the engine will not start.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">To accurately check the valve timing, it will be necessary to remove the timing cover to gain access to the timing gears.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">The gears or sprockets are fitted to the crankshaft and camshaft by keys so they can only be fitted in one position. However, they can be incorrectly lined up to each other.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span class=""><span lang="EN-GB" style="font-family:Arial">Th</span></span><span lang="EN-GB" style="font-family:Arial"> operators manual will indicate what the timing marks look like and in the case of chains, what the sprockets should line up with. Typical lining up marks for gears are shown below:</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial"> </span></p><span lang="EN-GB" style="color:rgb(0,0,0);font-size:12pt;font-family:Arial"><br clear="all" style> </span><span style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"></span><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial"> </span></p><p class="" align="center" style="margin:0cm 0cm 12pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-align:center;text-indent:70.9pt"> <b><i><span lang="EN-GB" style="font-family:Arial"><img border="0" width="351" height="265" src="http://www.splashmaritime.com.au/Marops/data/text/Med3tex/Engpropmed2_files/image014.jpg"></span></i></b></p><p class="" align="center" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-align:center;text-indent:70.9pt"> <b><i></i></b><b><i><span lang="EN-GB" style="font-family:Arial">Gear lining up marks</span></i></b></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial">When timing has been found to be correct, the tappet clearances (also referred to as valve lash) should be checked. Whenever the cylinder head is overhauled, the valves are reconditioned or replaced, or the valve operating mechanism is replaced or disturbed in any way, the tappet clearance must be adjusted.<i> </i><span class="">Also when the cylinder head has been re-tightened after the initial run in period.</span></span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span class=""><span lang="EN-GB" style="font-family:Arial">When the valve and valve operating gear heats up in service, the clearance between the rocker arm and the valve stem decreases.</span></span><span lang="EN-GB" style="font-family:Arial"> If insufficient clearance is allowed, the valve will be prevented from seating. The correct clearance will be specified by the engine manufacturer. In the Operators Manual, some manufacturers state clearances for when the engine is at its normal operating temperature, others when the engine is cold, while some give both.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">Clearances will vary as much as 0.128 mm (0.005") between a cold and the normal operating temperature of an engine. Usually, an exhaust valve will have a greater clearance than an inlet valve because of their different operating temperatures. Too much clearance will cause excessive wear, noisy operation and altered valve timing, that is, late opening and early closing.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">If the clearance is insufficient and the valve does not seat properly, it will result in:</span></p> <p class="" style="margin:0cm 0cm 4pt;text-indent:70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Symbol">·<span style="font-size:7pt;line-height:normal;font-family:'Times New Roman'"> </span></span><span dir="LTR"><span lang="EN-GB" style="font-family:Arial">loss of compression through valve leakage</span></span></p> <p class="" style="margin:0cm 0cm 4pt;text-indent:70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Symbol">·<span style="font-size:7pt;line-height:normal;font-family:'Times New Roman'"> </span></span><span dir="LTR"><span lang="EN-GB" style="font-family:Arial">burning and eroding of the valve and seat, and</span></span></p> <p class="" style="margin:0cm 0cm 12pt;text-indent:70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Symbol">·<span style="font-size:7pt;line-height:normal;font-family:'Times New Roman'"> </span></span><span dir="LTR"><span class=""><span lang="EN-GB" style="font-family:Arial">general</span></span></span><span lang="EN-GB" style="font-family:Arial"> overheating.</span></p> <p class="" style="margin:0cm 0cm 12pt 85.1pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial"> </span></p><span lang="EN-GB" style="color:rgb(0,0,0);font-size:12pt;font-family:Arial"><br clear="all" style> </span><span style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"></span><p class="" style="margin:0cm 0cm 12pt 85.1pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"> <span lang="EN-GB" style="font-family:Arial"> </span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">In the extreme, it is possible that the piston could strike the valve resulting in a bent valve stem, damaged piston or worse if the valve or piston should break.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><i><span lang="EN-GB" style="font-family:Arial">When the valve operating mechanism is disturbed in any way, the engine is cold, but only a hot tappet clearance is given, the tappet clearance must be checked. If required, a further adjustment when the engine is at its normal operating temperature.</span></i><span lang="EN-GB" style="font-family:Arial"></span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">The most common form of adjustment for tappet clearance is by means of a screw and lock nut located in one end of the rocker arm. The clearance is measured by means of a feeler gauge between the valve stem and rocker arm when the valve is in the fully closed position. This is usually done when the piston, under the valve being adjusted, is on top dead centre at the end of the compression stroke.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">An easy way to identify the above is as follows:</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">On a six cylinder engine with a firing order of 1 5 3 6 2 4, turn the engine over in the direction of rotation. When the inlet valve and exhaust valves are rocking on number 6 cylinder (<span class="">ie</span>. the piston finishing its exhaust stroke and starting its induction stroke) adjust the inlet and exhaust valve clearances on number 1 cylinder which will just be completing its compression stroke and commencing its power stroke.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">On the crankshaft, the bottom end journals on numbers 1 and 6 are 180° to each other, 2 and 5 are 180° to each other, and 3 and 4 are 180° to each other.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">What you are doing is adjusting number 1 tappets while number 6 is rocking, then adjust number 5 because it is the next one in the firing order to be on top dead centre while number 2 is rocking, adjust number 3 while number 4 is rocking, adjust number 6 while number 1 is rocking, adjust number 2 while number 5 is rocking, and adjust number 4 while number 3 is rocking.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">On a Detroit Diesel, the exhaust valve/s can be adjusted on the cylinder on which the unit injector follower is fully depressed. This means that fuel injection is taking place so it is at the end of the compression stroke and the beginning of the power stroke.</span></p> <p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial"> </span></p><div><br></div>-- <br><div dir="ltr"> <div style="text-align:center"><font size="1"><u><b><font color="#ff0000">M</font><a href="http://marinenotes.blogspot.in" style="color:rgb(255,0,0)" target="_blank"><font>arineN</font>otes.blogspot.in</a></b></u></font></div> <div style="text-align:center"><div><img src="http://i844.photobucket.com/albums/ab3/283928/b_dl.gif"><a href="http://marinenotesonline.blogspot.in/p/buy-marine-notes.html" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/b_buy.gif"></a><font color="#ff0000"><a href="http://marinenotesonline.blogspot.com/p/marine-notes-online-order-form-var.html" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/WriteDocument_zps380e535b.png"></a><a href="mailto:marinenotesonline@gmail.com" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/1310735291_icon-email_zps9ea76f56.jpg"></a><br> Free Download <b><span style="color:rgb(0,0,255)">&</span></b> Buy Online via Secure Paypal </font><font color="#0000ff">or</font><font color="#ff0000"> Fill Order Form.</font></div><div><b style="color:rgb(0,0,255)"><font size="1"><a href="http://marinenotesonline.blogspot.in/" target="_blank">Marine Notes Online</a></font></b></div> <br></div></div> </div> <div class="blogger-post-footer"><script type="text/javascript"><!--
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Because of the very short space of time available in a diesel engine in which the fuel and air can mix, various methods have been devised in an attempt to give improved mixing and combustion.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial"> </span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial"> </span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial"> </span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">Combustion chambers can be of several designs but all are concerned in creating turbulence to the air during the compression stroke. In the diesel engine, the fuel is in the form of fine particles sprayed into the cylinder after the air has been compressed. To secure complete combustion, each particle of fuel must be surrounded by sufficient air. The mixing of the air and fuel is greatly assisted by the combustion chamber air turbulence.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">Some engines have helical inlet ports to provide additional swirl.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">Generally, combustion systems can be classified as direct and indirect injection types.</span></p> <span lang="EN-GB" style="color:rgb(0,0,0);font-size:12pt;font-family:Arial"><br clear="all" style></span><span style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"></span><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial"> </span></p><p class="" style="margin:0cm 0cm 4pt;text-indent:70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Symbol">·<span style="font-size:7pt;line-height:normal;font-family:'Times New Roman'"> </span></span><span dir="LTR"><span lang="EN-GB" style="font-family:Arial">Direct injection.</span></span></p> <p class="" style="margin:0cm 0cm 4pt;text-indent:70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Symbol">·<span style="font-size:7pt;line-height:normal;font-family:'Times New Roman'"> </span></span><span dir="LTR"><span lang="EN-GB" style="font-family:Arial">Indirect injection, the two most common types being:</span></span></p> <p class="" style="margin:0cm 0cm 4pt;text-indent:70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Symbol">·<span style="font-size:7pt;line-height:normal;font-family:'Times New Roman'"> </span></span><span dir="LTR"><span lang="EN-GB" style="font-family:Arial">Turbulence chamber and</span></span></p> <p class="" style="margin:0cm 0cm 4pt;text-indent:70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Symbol">·<span style="font-size:7pt;line-height:normal;font-family:'Times New Roman'"> </span></span><span dir="LTR"><span lang="EN-GB" style="font-family:Arial">Pre-combustion chamber.<b></b></span></span></p> <p class="" style="margin:0cm 0cm 4pt;text-indent:70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Symbol">·<span style="font-size:7pt;line-height:normal;font-family:'Times New Roman'"> </span></span><span dir="LTR"><b><span lang="EN-GB" style="font-family:Arial"> </span></b></span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">The larger, slow speed engines and medium speed engines do not have the same difficulty in achieving good combustion as small high speed engines.</span></p> <p class="" style="margin:12pt 0cm 6pt;line-height:16pt;font-size:16pt;font-family:'Arial Narrow';font-weight:bold;color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial">Direct injection</span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial"> </span></p><p class="" align="center" style="margin:0cm 0cm 12pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-align:center;text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial"><img border="0" width="328" height="237" src="http://www.splashmaritime.com.au/Marops/data/text/Med3tex/Engpropmed2_files/image008.jpg"></span></p><p class="" align="center" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-align:center;text-indent:70.9pt"> <b><i></i></b><b><i><span lang="EN-GB" style="font-family:Arial">Direct injection combustion chamber</span></i></b></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial">With direct injection, the fuel is injected directly into the combustion chamber which is usually formed by a cavity in the piston crown. </span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial">This cavity is carefully shaped to promote air swirl and the direction of the injector nozzle ensures that rapid mixing of the fuel and air assists complete combustion.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><b><span lang="EN-GB" style="font-family:Arial">Advantages</span></b><span lang="EN-GB" style="font-family:Arial"> - It is claimed that direct injection gives higher thermal efficiency with lower fuel consumption. This is bought about by the fact that no heat is lost or power wasted in pumping air through a restricted opening into the separate chamber or in discharging the gases from the chamber. This gives easier starting and generally this type of engine does not require a starting aid device, such as glow plugs.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><b><span lang="EN-GB" style="font-family:Arial">Disadvantages</span></b><span lang="EN-GB" style="font-family:Arial"> - This kind of injection is prone to "diesel knock".</span></p> <b style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"><span lang="EN-GB" style="font-size:16pt;font-family:Arial"><br clear="all" style></span></b><span style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"></span><p class="" style="margin:12pt 0cm 6pt;line-height:16pt;font-size:16pt;font-family:'Arial Narrow';font-weight:bold;color:rgb(0,0,0)"> <span lang="EN-GB" style="font-family:Arial">Indirect injection</span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial"> </span></p><p class="" align="center" style="margin:0cm 0cm 12pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-align:center;text-indent:70.9pt"> <b><i><span lang="EN-GB" style="font-family:Arial"><img border="0" width="220" height="250" src="http://www.splashmaritime.com.au/Marops/data/text/Med3tex/Engpropmed2_files/image010.jpg"></span></i></b></p><p class="" align="center" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-align:center;text-indent:70.9pt"> <b><i></i></b><b><i><span lang="EN-GB" style="font-family:Arial">Pre-combustion piston</span></i></b></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial">The indirect injection or separate chamber system is where a separate small chamber is connected to the main chamber by a narrow passage or orifice.</span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial">The pre-combustion chamber and the turbulence chamber (also called a compression swirl chamber) work on the same principle. The main physical difference is the location and size of the connecting passage.</span></p> <p class="" align="center" style="margin:0cm 0cm 12pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-align:center;text-indent:70.9pt"><b><i><span lang="EN-GB" style="font-family:Arial"><img border="0" width="307" height="281" src="http://www.splashmaritime.com.au/Marops/data/text/Med3tex/Engpropmed2_files/image012.jpg"></span></i></b></p> <p class="" align="center" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-align:center;text-indent:70.9pt"><b><i></i></b><b><i><span lang="EN-GB" style="font-family:Arial">Swirl Chamber</span></i></b></p> <b style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"><i><span lang="EN-GB" style="font-size:12pt;font-family:Arial"><br clear="all" style></span></i></b><span style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"></span><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <b><i><span lang="EN-GB" style="font-family:Arial"> </span></i></b></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">With pre-combustion chambers only about 30% of the combustion air is forced into the chamber, fuel is injected and primary burning takes place in the chamber. This prevents too sudden a rise in pressure which can contribute to the so called 'diesel knock'. The burning mixture of fuel and air is vigorously expelled through the connecting passage into the main combustion chamber or cylinder where an excess of air permits combustion to be completed.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><b><span lang="EN-GB" style="font-family:Arial">Advantages</span></b><span lang="EN-GB" style="font-family:Arial"> - lower injection pressures can be used, resulting in less wear of injector nozzles; simpler design of nozzle equipment, which are easier to maintain, and smoother idling of the engine.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">Engine manufacturers may in some instances use either design in their range, depending on operating requirements.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span class=""><b><span lang="EN-GB" style="font-family:Arial">Disadvantages</span></b><span lang="EN-GB" style="font-family:Arial"> - not as efficient as direct injection.</span></span><span lang="EN-GB" style="font-family:Arial"> It can also be prone to pre-combustion burn-out.</span></p> <div><br></div>-- <br><div dir="ltr"><div style="text-align:center"><font size="1"><u><b><font color="#ff0000">M</font><a href="http://marinenotes.blogspot.in" style="color:rgb(255,0,0)" target="_blank"><font>arineN</font>otes.blogspot.in</a></b></u></font></div> <div style="text-align:center"><div><img src="http://i844.photobucket.com/albums/ab3/283928/b_dl.gif"><a href="http://marinenotesonline.blogspot.in/p/buy-marine-notes.html" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/b_buy.gif"></a><font color="#ff0000"><a href="http://marinenotesonline.blogspot.com/p/marine-notes-online-order-form-var.html" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/WriteDocument_zps380e535b.png"></a><a href="mailto:marinenotesonline@gmail.com" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/1310735291_icon-email_zps9ea76f56.jpg"></a><br> Free Download <b><span style="color:rgb(0,0,255)">&</span></b> Buy Online via Secure Paypal </font><font color="#0000ff">or</font><font color="#ff0000"> Fill Order Form.</font></div><div><b style="color:rgb(0,0,255)"><font size="1"><a href="http://marinenotesonline.blogspot.in/" target="_blank">Marine Notes Online</a></font></b></div> <br></div></div> </div> <div class="blogger-post-footer"><script type="text/javascript"><!--
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</center></div>Marine Noteshttp://www.blogger.com/profile/14270820931606062583noreply@blogger.com0tag:blogger.com,1999:blog-838411897140673717.post-54882567775659416862013-03-23T09:18:00.001+05:302013-03-23T09:18:51.763+05:30Operating principles of engines<div dir="ltr"><p class="" style="margin:24pt 0cm 12pt;line-height:38pt;font-size:16pt;font-family:Arial;font-weight:bold;color:rgb(0,0,0)"><span lang="EN-GB">Operating principles of engines</span><span lang="EN-GB"></span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial">There are two types of diesel engines, a four stroke cycle and a two stroke cycle.</span></p> <p class="" style="margin:20pt 0cm 8pt;line-height:20pt;font-size:18pt;font-family:'Arial Narrow';font-weight:bold;color:rgb(0,0,0)"><span lang="EN-GB" style="font-size:16pt;font-family:Arial">Four stroke cycle diesel engine</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial">In a four stroke cycle engine, four strokes of the piston are required to complete one cycle. The four strokes are induction, compression, power and exhaust.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial">The actual opening and closing of the inlet and exhaust valves and the period of injection of the fuel can be taken from the timing diagram. Timing diagrams will vary between engine models and manufacturers.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial"> </span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"> <span lang="EN-GB" style="font-family:Arial"> </span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial"> </span></p> <p class="" style="margin:0cm 0cm 12pt 70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial"> </span></p><p class="" style="margin:0cm 0cm 12pt 70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"> <span lang="EN-GB" style="font-family:Arial"> </span></p><p class="" style="margin:0cm 0cm 12pt 70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial"> </span></p> <p class="" style="margin:0cm 0cm 12pt 70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><span lang="EN-GB" style="font-family:Arial"> </span></p><span lang="EN-GB" style="color:rgb(0,0,0);font-size:12pt;font-family:Arial"><br clear="all" style> </span><span style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"></span><p class="" style="margin:0cm 0cm 12pt 70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"> <span lang="EN-GB" style="font-family:Arial"> </span></p><p class="" align="center" style="margin:0cm 0cm 12pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-align:center"><span lang="EN-GB" style="font-family:Arial"><img border="0" width="554" height="486" src="http://www.splashmaritime.com.au/Marops/data/text/Med3tex/Engpropmed2_files/image004.gif"></span></p> <p class="" align="center" style="margin:0cm 0cm 12pt 70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-align:center"><b><i></i></b><b><span lang="EN-GB" style="font-family:Arial"><i>Four stroke timing diagram.</i></span></b></p> <span lang="EN-GB" style="color:rgb(0,0,0);font-size:12pt;font-family:Arial"><br clear="all" style></span><span style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"></span><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial">The above diagram is for a Caterpillar series 3600 turbo charged after cooled engine. As can be seen from the timing diagram, the induction stroke commences when the inlet valve opens 10° before TDC when air is drawn into the cylinder as the piston moves down. The inlet valve closes 1° before BDC.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">The air is now trapped in the cylinder and as the piston rises on the compression stroke, the air is compressed. As the air is compressed, it rises in temperature. When the piston reaches 19° before TDC, the injection of fuel commences and continues until 73° after TDC.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">The heat in the compressed air ignites the fuel and combustion takes place. The gases expand forcing the piston down on the power stroke.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">The exhaust valves opens at 26° before BDC and the exhaust gases commence and are discharged as the piston rises on the exhaust stroke. Most of the exhaust gases have been discharged as the piston nears TDC. However, at 10° before TDC, the inlet valve opens and air enters the cylinder and helps discharge any remaining exhaust gases until the exhaust valve closes at 3° after TDC.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">The whole cycle is then repeated.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">Both the exhaust valve and inlet valve are open from 10° before TDC to 3° after TDC, an overlap of 13°. This is referred to as "valve overlap" and ensures that all the exhaust gases are discharged from the cylinder and the cylinder receives a <span class="">fresh charge</span> of air to make it more efficient when combustion next takes place.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">Therefore there is one power stroke for every cycle or two revolutions of the crankshaft.</span></p> <p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';color:rgb(0,0,0)"><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial">Two stroke cycle diesel engine</span></b></p> <p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';color:rgb(0,0,0)"><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial"> </span></b></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial">In a two stroke cycle engine, two strokes of the piston are required to complete one cycle.</span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial">The two strokes are compression and power. The events of compression, injection of the fuel, combustion and expansion of the gases take place in the same order as the four stroke engine, but the exhaust of the burnt gases and the induction of air take place at the bottom of its stroke. This is the chief difference between the two stroke cycle and the four stroke cycle.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">There are variations in two stroke cycle engines. The type described here is the most common to be found in marine engines. It has inlet ports and exhaust valves.</span></p> <span lang="EN-GB" style="color:rgb(0,0,0);font-size:12pt;font-family:Arial"><br clear="all" style></span><span style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"></span><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial"> </span></p><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">In this two stroke cycle engine, all the valves are exhaust. The inlet holes or ports are in the lower section of the cylinder liner wall.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">The piston uncovers the inlet ports as it moves down the cylinder. The piston covers the inlet ports as it moves up the cylinder. This action has the same effect as a valve opening and closing.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">An engine driven scavenge blower is fitted and the incoming air is blown into the cylinder through the inlet ports when they are uncovered by the piston.</span></p> <p class="" align="center" style="margin:0cm 0cm 12pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-align:center;text-indent:70.9pt"><b><i><span lang="EN-GB" style="font-family:Arial"><img border="0" width="491" height="422" src="http://www.splashmaritime.com.au/Marops/data/text/Med3tex/Engpropmed2_files/image006.gif"></span></i></b></p> <p class="" align="center" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-align:center;text-indent:70.9pt"><b><i></i></b><b><i><span lang="EN-GB" style="font-family:Arial">Two stroke timing diagram.</span></i></b></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">The above timing diagram is for a Detroit Diesel model 16V-149 turbo charged inter cooled engine. As can be seen from the timing diagram above<span class="">, induction</span> commences at 49° before BDC when the piston has uncovered the inlet ports. Air is forced into the cylinder by the scavenge blower as the piston moves down to BDC and back up again until it covers the inlet ports at 49° after BDC.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">As the piston rises, the exhaust valve closes at 62° after BDC. The air is now trapped in the cylinder and the piston rises on the compression stroke. As the air is compressed, it rises in temperature.</span></p> <span lang="EN-GB" style="color:rgb(0,0,0);font-size:12pt;font-family:Arial"><br clear="all" style></span><span style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"></span><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"> <span lang="EN-GB" style="font-family:Arial">Fuel is injected before TDC and continues after TDC. Detroit Diesel <span class="">do</span> not give the period of injection as this will vary depending upon the engine speed, the load and the size of the injectors. The camshaft contains the exhaust valve cams as well as the unit injector cams. Therefore, if the exhaust valve timing is correct, the unit injector timing will be correct providing the injector follower is adjusted to a definite height in relation to the unit injector. A special gauge is supplied to set this height.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">The heat in the compressed air ignites the fuel and combustion takes place. The gases expand forcing the piston down on the power stroke.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">The exhaust valve opens at 83° before BDC allowing the burned gases to escape into the exhaust manifold. However, at 49° before BDC, the inlet ports are uncovered by the piston and air enters the cylinder and helps discharge any remaining exhaust gases until the exhaust valve closes at 62° after BDC.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">The whole cycle is then repeated.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-indent:70.9pt"><span lang="EN-GB" style="font-family:Arial">There is one power stroke for every one revolution of the crankshaft.</span></p> <div><br></div>-- <br><div dir="ltr"><div style="text-align:center"><font size="1"><u><b><font color="#ff0000">M</font><a href="http://marinenotes.blogspot.in" style="color:rgb(255,0,0)" target="_blank"><font>arineN</font>otes.blogspot.in</a></b></u></font></div> <div style="text-align:center"><div><img src="http://i844.photobucket.com/albums/ab3/283928/b_dl.gif"><a href="http://marinenotesonline.blogspot.in/p/buy-marine-notes.html" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/b_buy.gif"></a><font color="#ff0000"><a href="http://marinenotesonline.blogspot.com/p/marine-notes-online-order-form-var.html" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/WriteDocument_zps380e535b.png"></a><a href="mailto:marinenotesonline@gmail.com" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/1310735291_icon-email_zps9ea76f56.jpg"></a><br> Free Download <b><span style="color:rgb(0,0,255)">&</span></b> Buy Online via Secure Paypal </font><font color="#0000ff">or</font><font color="#ff0000"> Fill Order Form.</font></div><div><b style="color:rgb(0,0,255)"><font size="1"><a href="http://marinenotesonline.blogspot.in/" target="_blank">Marine Notes Online</a></font></b></div> <br></div></div> </div> <div class="blogger-post-footer"><script type="text/javascript"><!--
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</center></div>Marine Noteshttp://www.blogger.com/profile/14270820931606062583noreply@blogger.com0tag:blogger.com,1999:blog-838411897140673717.post-31113300480412072852013-03-23T09:17:00.001+05:302013-03-23T09:17:56.798+05:30Common Terminology of Engines.<div dir="ltr"><div align="center" style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"><table class="" border="0" cellspacing="0" cellpadding="0" style="border-collapse:collapse"><tbody><tr><td width="170" valign="top" style="width:127.6pt;padding:0cm 5.4pt"> <p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';text-align:justify"><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial">Force</span></b><span lang="EN-GB" style="font-family:Arial"></span></p> </td><td width="423" valign="top" style="width:317.15pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span class=""><span lang="EN-GB" style="font-family:Arial">It is</span></span><span lang="EN-GB" style="font-family:Arial"> the influence which tends to change the motion or direction of a body at rest or in motion. A simple explanation is pushing or pulling.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span lang="EN-GB" style="font-family:Arial">From the above, applying a force would either:</span></p> <p class="" style="margin:0cm 0cm 4pt;text-indent:0cm;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span lang="EN-GB" style="font-family:Symbol">·<span style="font-size:7pt;line-height:normal;font-family:'Times New Roman'"> </span></span><span dir="LTR"><span lang="EN-GB" style="font-family:Arial">Start moving a body from rest or bring a moving body to rest.</span></span></p> <p class="" style="margin:0cm 0cm 4pt;text-indent:0cm;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span lang="EN-GB" style="font-family:Symbol">·<span style="font-size:7pt;line-height:normal;font-family:'Times New Roman'"> </span></span><span dir="LTR"><span lang="EN-GB" style="font-family:Arial">Increase or decrease the speed of a moving body.</span></span></p> <p class="" style="margin:0cm 0cm 12pt;text-indent:0cm;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span lang="EN-GB" style="font-family:Symbol">·<span style="font-size:7pt;line-height:normal;font-family:'Times New Roman'"> </span></span><span dir="LTR"><span lang="EN-GB" style="font-family:Arial">Change the direction of motion of a moving body.</span></span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span lang="EN-GB" style="font-family:Arial">Force is measured in <span class="">newtons</span> (N).<b></b></span></p> <p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';text-align:justify"><span lang="EN-GB" style="font-family:Arial"> </span></p></td></tr><tr><td width="170" valign="top" style="width:127.6pt;padding:0cm 5.4pt"> <p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';text-align:justify"><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial">Work</span></b></p></td><td width="423" valign="top" style="width:317.15pt;padding:0cm 5.4pt"> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span class=""><span lang="EN-GB" style="font-family:Arial">is</span></span><span lang="EN-GB" style="font-family:Arial"> the use of energy to overcome resistance. The amount of work done is from moving an applied force through a distance. The unit of measurement of doing work is the joule.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span lang="EN-GB" style="font-family:Arial">The force is measured in <span class="">newtons</span> (N) and the distance is measured in metres (m). From the formula Work = Force x Distance, work would be in <span class="">newton</span> metres (Nm). To prevent confusion between 'work' and 'torque', the unit given to the formula for work is the joule (j).</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span lang="EN-GB" style="font-family:Arial">One <span class="">newton</span> metre = one joule.</span></p> </td></tr><tr><td width="170" valign="top" style="width:127.6pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';text-align:justify"><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial">Torque</span></b></p> </td><td width="423" valign="top" style="width:317.15pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span class=""><span lang="EN-GB" style="font-family:Arial">is</span></span><span lang="EN-GB" style="font-family:Arial"> when a force tends to cause a movement about a point. Torque is also called a turning or twisting effort. Torque = Force x Distance. Torque is the <b>force exerted</b>, but not<b>moved</b>, over a distance.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span lang="EN-GB" style="font-family:Arial">Force is measured in <span class="">newtons</span> (N) and distance is measured in metres (m). Torque is therefore measured in <span class="">newton</span>metres (Nm).</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span lang="EN-GB" style="font-family:Arial">As an example, the force on the piston of an engine exerts a turning moment on the crankshaft.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span lang="EN-GB" style="font-family:Arial"> </span></p></td></tr><tr><td width="170" valign="top" style="width:127.6pt;padding:0cm 5.4pt"> <p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';text-align:justify"><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial">Power</span></b></p></td><td width="423" valign="top" style="width:317.15pt;padding:0cm 5.4pt"> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span class=""><span lang="EN-GB" style="font-family:Arial">is</span></span><span lang="EN-GB" style="font-family:Arial"> the amount of work done or energy expanded in a given time.<b> </b>Also expressed as<b> </b>the capacity to do work. Watt (W) is the unit measurement of power. A watt is the power used when energy is expended or work done at the rate of one joule per second.<b></b></span></p> <p class="" style="margin:0cm 0cm 0.0001pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify;background-color:rgb(204,204,204)"><b><span lang="EN-GB" style="font-family:Arial">Power = <u>Force x Distance</u></span></b></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify;background-color:rgb(204,204,204)"><b><span lang="EN-GB" style="font-family:Arial"> Time in seconds</span></b><span lang="EN-GB" style="font-family:Arial"></span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span lang="EN-GB" style="font-family:Arial">As force is in <span class="">newtons</span> (N), distance in metres (m), and time in seconds (s), the answer will be in <span class="">newton</span> metres per second or joules per second. (1 <span class="">newton</span> metre = 1 joule). However, as one joule per second = one watt, the final answer will be in watts.</span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span lang="EN-GB" style="font-family:Arial">Power of an engine is measured in kilowatts (kW) rather than watts (W). 1000 W = 1 kW.</span></p> </td></tr><tr><td width="170" valign="top" style="width:127.6pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';text-align:justify"><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial">Thermal efficiency</span></b></p> </td><td width="423" valign="top" style="width:317.15pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span lang="EN-GB" style="font-family:Arial">Thermal efficiency is the ratio of work done at the flywheel to the amount of energy contained in the fuel. Thermal efficiency is expressed as a percentage.</span></p> </td></tr><tr><td width="170" valign="top" style="width:127.6pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';text-align:justify"><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial">Calorific value</span></b></p> </td><td width="423" valign="top" style="width:317.15pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span lang="EN-GB" style="font-family:Arial">Fuel contains a specific amount of heat energy or heat value which is released when the fuel is burnt. This is the calorific value of the fuel. It is measured in joules per kilogram of fuel.</span></p> </td></tr><tr><td width="170" valign="top" style="width:127.6pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';text-align:justify"><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial">Volumetric efficiency</span></b></p> </td><td width="423" valign="top" style="width:317.15pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span class=""><span lang="EN-GB" style="font-family:Arial">is</span></span><span lang="EN-GB" style="font-family:Arial"> the ratio between the swept volume of a cylinder and the actual volume of air drawn in during the induction stroke. The efficiency varies considerably, depending on the design and operating conditions but especially with engine speed. A turbo charged engine will have a higher volumetric efficiency (in excess of 100%) than that of a normally aspirated engine (less than 100%). Swept volume is the volume in the cylinder between TDC and BDC of the piston.</span></p> </td></tr><tr><td width="170" valign="top" style="width:127.6pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';text-align:justify"><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial">Turbulence</span></b></p> </td><td width="423" valign="top" style="width:317.15pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span class=""><span lang="EN-GB" style="font-family:Arial">also</span></span><span lang="EN-GB" style="font-family:Arial"> called swirl, is the circular movement of the air as it enters the combustion chamber. The swirling motion or turbulence is encouraged by design considerations as it enhances flame propagation and is especially important at light engine loads. It is a desirable characteristic in the flow of air into the cylinder. In most engines, a rapidly swirling motion is deliberately induced and the violent movement helps ensure even mixing of the fuel and air. It also speeds up the combustion process once the fuel has ignited.</span></p> </td></tr><tr><td width="170" valign="top" style="width:127.6pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';text-align:justify"><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial">Scavenging</span></b></p> </td><td width="423" valign="top" style="width:317.15pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span class=""><span lang="EN-GB" style="font-family:Arial">is</span></span><span lang="EN-GB" style="font-family:Arial"> the term used for eliminating the burned exhaust gases from a cylinder. The incoming air removes, or scavenges, as much of the burnt gases as possible. Valve overlap assists in the scavenging process.</span></p> </td></tr><tr><td width="170" valign="top" style="width:127.6pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';text-align:justify"><b><span lang="EN-GB" style="font-size:15pt;font-family:Arial">Compression ratio</span></b><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial"></span></b></p> </td><td width="423" valign="top" style="width:317.15pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span class=""><span lang="EN-GB" style="font-family:Arial">is</span></span><span lang="EN-GB" style="font-family:Arial"> the ratio between the volume of the air before and after it has been subject to compression. A compression ratio of 12:1 means that during the pistons travel from the lowest to the highest point in the cylinder, the air has been compressed to one-twelfth its original volume. A diesel engine needs a high compression ratio to get sufficient heat in the compressed air to ignite the fuel.</span></p> <p class="" style="margin:0cm 0cm 2pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify;background-color:rgb(204,204,204)"><b><span lang="EN-GB" style="font-family:Arial">Compression</span></b></p> <p class="" style="margin:0cm 0cm 2pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify;background-color:rgb(204,204,204)"><b><span lang="EN-GB" style="font-family:Arial"> ratio = <u>piston displacement + clearance volume</u></span></b></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify;background-color:rgb(204,204,204)"><b><span lang="EN-GB" style="font-family:Arial"> clearance volume</span></b><span lang="EN-GB" style="font-family:Arial"></span></p> </td></tr><tr><td width="170" valign="top" style="width:127.6pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';text-align:justify"><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial">Valve overlap</span></b><b><span lang="EN-GB" style="font-size:14pt;font-family:Arial"></span></b></p> </td><td width="423" valign="top" style="width:317.15pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span class=""><span lang="EN-GB" style="font-family:Arial">is</span></span><span lang="EN-GB" style="font-family:Arial"> the period which both the inlet valve and exhaust valve are open at the same time. The inlet valve opens before top dead centre (TDC), say at 10° and the exhaust valve closes after TDC, say at 35°. The opening of the inlet valve overlaps the closing of the exhaust valve. The overlap in this case would be 35<span class="">° .</span></span></p> <p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span lang="EN-GB" style="font-family:Arial">The purpose of valve overlap is to ensure that are exhaust gases are discharged from the cylinder and the cylinder receives a fresh charge of air to make it more efficient when combustion next takes place. It also has a cooling effect.</span></p> </td></tr><tr><td width="170" valign="top" style="width:127.6pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';text-align:justify"><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial">Valve rotators</span></b></p> </td><td width="423" valign="top" style="width:317.15pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span class=""><span lang="EN-GB" style="font-family:Arial">are</span></span><span lang="EN-GB" style="font-family:Arial"> devices which cause a valve to rotate each time it opens. It can be fitted to either end of the valve spring. Its purpose is to ensure even wear and prevent exhaust valves from burn out.</span></p> </td></tr><tr><td width="170" valign="top" style="width:127.6pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';text-align:justify"><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial">Dwell</span></b></p> </td><td width="423" valign="top" style="width:317.15pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman';text-align:justify"><span class=""><span lang="EN-GB" style="font-family:Arial">is</span></span><span lang="EN-GB" style="font-family:Arial"> the angle that the valve remains in the fully open position. The profile of the lobe of the cam causes the valve to open until the lobe flattens out. The valve stays in this fully open position which is the angle of dwell until the other side of the lobe is reached when the valve starts to close.</span></p> </td></tr></tbody></table></div><span lang="EN-GB" style="color:rgb(0,0,0);font-size:10pt;font-family:Arial"><br clear="all" style></span><span style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"></span><p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman';color:rgb(0,0,0)"> <span lang="EN-GB" style="font-family:Arial"> </span></p><div align="center" style="color:rgb(0,0,0);font-family:'Times New Roman';font-size:medium"><table class="" border="0" cellspacing="0" cellpadding="0" width="574" style="width:430.4pt;margin-left:19.8pt;border-collapse:collapse"> <tbody><tr style><td width="183" valign="top" style="width:137.25pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 0.0001pt;font-size:10pt;font-family:'Times New Roman'"><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial">Cam</span></b><b><span lang="EN-GB" style="font-size:16pt;font-family:Arial"> lift</span></b></p> </td><td width="391" valign="top" style="width:293.15pt;padding:0cm 5.4pt"><p class="" style="margin:0cm 0cm 12pt;line-height:14pt;font-size:12pt;font-family:'Times New Roman'"><span class=""><span lang="EN-GB" style="font-family:Arial">is</span></span><span lang="EN-GB" style="font-family:Arial"> the distance from the peak of the lobe of a cam to its axis minus the distance from the back of the cam to its axis. Another description would be the distance the valve opens plus the valve lash or tappet clearance measurement.</span></p> </td></tr></tbody></table></div><p class="" style="margin:0cm 0cm 12pt 70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0)"><b><span lang="EN-GB" style="font-family:Arial"> </span></b></p> <p class="" align="center" style="margin:0cm 0cm 12pt 70.9pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-align:center"><b><i><span lang="EN-GB" style="font-family:Arial"><img border="0" width="329" height="300" src="http://www.splashmaritime.com.au/Marops/data/text/Med3tex/Engpropmed2_files/image002.jpg"></span></i></b></p> <p class="" align="center" style="margin:0cm 0cm 12pt 70.9pt;line-height:14pt;font-size:medium;font-family:'Times New Roman';color:rgb(0,0,0);text-align:center"><b><i></i></b><b><i><span lang="EN-GB" style="font-family:Arial">Cam</span></i></b><b><i><span lang="EN-GB" style="font-family:Arial"> profile</span></i></b></p> <div><br></div>-- <br><div dir="ltr"><div style="text-align:center"><font size="1"><u><b><font color="#ff0000">M</font><a href="http://marinenotes.blogspot.in" style="color:rgb(255,0,0)" target="_blank"><font>arineN</font>otes.blogspot.in</a></b></u></font></div> <div style="text-align:center"><div><a href="http://marinenotesonline.blogspot.in/p/buy-marine-notes.html" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/b_buy.gif"></a><font color="#ff0000"><a href="http://marinenotesonline.blogspot.com/p/marine-notes-online-order-form-var.html" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/WriteDocument_zps380e535b.png"></a><a href="mailto:marinenotesonline@gmail.com" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/1310735291_icon-email_zps9ea76f56.jpg"></a><br> Free Download <b><span style="color:rgb(0,0,255)">&</span></b> Buy Online via Secure Paypal </font><font color="#0000ff">or</font><font color="#ff0000"> Fill Order Form.</font></div><div><b style="color:rgb(0,0,255)"><font size="1"><a href="http://marinenotesonline.blogspot.in/" target="_blank">Marine Notes Online</a></font></b></div> <br></div></div> </div> <div class="blogger-post-footer"><script type="text/javascript"><!--
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During the second half of the 19th century, when development of the modern reciprocating internal combustion engine was in its early stages, many types of engines operating on many different cycles were tried. These include various two, four, and even six stroke cycles. Six stroke cycles were similar to four stroke cycles with two added strokes for additional exhaust removal (ie three revolutions per cycle instead of two).<br />
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</center></div>Marine Noteshttp://www.blogger.com/profile/14270820931606062583noreply@blogger.com0tag:blogger.com,1999:blog-838411897140673717.post-80628097593349263172013-01-27T03:29:00.001+05:302013-01-27T03:29:34.438+05:30HANDBOOK ELECTRICAL ENGINEERING CATHODIC PROTECTION<div dir="ltr"><b style="text-align:center">HANDBOOK ELECTRICAL ENGINEERING CATHODIC PROTECTION</b><br><div class="gmail_quote"><div dir="ltr"><div style="text-align:center"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixUtx57q-OXdck2hEwJIgC_qCgZGZVPrIeR5YBKGhX14hgavFma4JGFEND0TdhRMEvk3Z53mRTDy4sIVce07itHVJxabV05HqKpPqnn1CaotYSdKSu1rqEQWb9FQ-LHbcq-jfi9ia9Am65/s1600/MILITARY+HANDBOOK+ELECTRICAL+ENGINEERING+CATHODIC+PROTECTION-735592.jpg" target="_blank"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixUtx57q-OXdck2hEwJIgC_qCgZGZVPrIeR5YBKGhX14hgavFma4JGFEND0TdhRMEvk3Z53mRTDy4sIVce07itHVJxabV05HqKpPqnn1CaotYSdKSu1rqEQWb9FQ-LHbcq-jfi9ia9Am65/s320/MILITARY+HANDBOOK+ELECTRICAL+ENGINEERING+CATHODIC+PROTECTION-735592.jpg" border="0" alt=""></a><br> <b>HANDBOOK ELECTRICAL ENGINEERING CATHODIC PROTECTION (<a href="http://marinenotesonline.blogspot.com" target="_blank">marinenotesonline.blogspot.com</a>)</b><br> <br><div style="text-align:left">ELECTRICAL ENGINEERING CATHODIC PROTECTION<br> CONTENTS<br>Page<br>Section 1 INTRODUCTION<br>1.1 Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1<br>1.2 Cancellation. . . . . . . . . . . . . . . . . . . . . . . . . 1<br> 1.3 Related Technical Documents. . . . . . . . . . . . . . . . . 1<br> Section 2 CATHODIC PROTECTION CONCEPTS<br>2.1 Corrosion as an Electrochemical Process. . . . . . . . . . . 3<br>2.1.1 Driving Force. . . . . . . . . . . . . . . . . . . . . . . . 3<br> 2.1.2 The Electrochemical Cell. . . . . . . . . . . . . . . . . . . 3<br> 2.1.2.1 Components of the Electrochemical Cell. . . . . . . . . . . . 3<br>2.1.2.2 Reactions in an Electrochemical Cell. . . . . . . . . . . . . 3<br> 2.2 The Electrochemical Basis for Cathodic<br>Protection. . . . . . . . . . . . . . . . . . . . . . . . . . 4<br> 2.2.1 Potentials Required for Cathodic Protection. . . . . . . . . 4<br>2.3 Practical Application of Cathodic Protection. . . . . . . . . 5<br> 2.3.1 When Cathodic Protection Should Be Considered. . . . . . . . 5<br>2.3.1.1 Where Feasible. . . . . . . . . . . . . . . . . . . . . . . . 5<br> 2.3.1.2 When Indicated By Experience. . . . . . . . . . . . . . . . . 5<br> 2.3.1.3 As Required By Regulation. . . . . . . . . . . . . . . . . . 5<br>2.3.2 Functional Requirements for Cathodic Protection . . . . . . . 8<br> 2.3.2.1 Continuity. . . . . . . . . . . . . . . . . . . . . . . . . . 8<br> 2.3.2.2 Electrolyte. . . . . . . . . . . . . . . . . . . . . . . . . 8<br>2.3.2.3 Source of Current. . . . . . . . . . . . . . . . . . . . . . 8<br> 2.3.2.4 Connection to Structure. . . . . . . . . . . . . . . . . . . 8<br> 2.4 Sacrificial Anode Systems. . . . . . . . . . . . . . . . . . 8<br>2.4.1 Anode Materials. . . . . . . . . . . . . . . . . . . . . . . 9<br>2.4.2 Connection to Structure. . . . . . . . . . . . . . . . . . . 10<br> 2.4.3 Other Requirements. . . . . . . . . . . . . . . . . . . . . . 10<br> 2.5 Impressed Current Systems. . . . . . . . . . . . . . . . . . 10<br>2.5.1 Anode Materials. . . . . . . . . . . . . . . . . . . . . . . 10<br>2.5.2 Direct Current Power Source. . . . . . . . . . . . . . . . . 10<br> 2.5.3 Connection to Structure. . . . . . . . . . . . . . . . . . . 10<br> 2.5.4 Other Requirements. . . . . . . . . . . . . . . . . . . . . . 11<br>Section 3 CRITERIA FOR CATHODIC PROTECTION<br>3.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . 13<br> 3.2 Electrical Criteria. . . . . . . . . . . . . . . . . . . . . 13<br> 3.3 Interpretation of Structure-to-Electrolyte<br>Potential Readings. . . . . . . . . . . . . . . . . . . . . . 13<br>3.3.1 National Association of Corrosion Engineers<br> (NACE)Standard RP-01-69. . . . . . . . . . . . . . . . . . . 13<br> 3.3.1.1 Criteria for Steel. . . . . . . . . . . . . . . . . . . . . . 15<br>3.3.1.2 Criteria for Aluminum. . . . . . . . . . . . . . . . . . . . 15<br>3.3.1.3 Criteria for Copper. . . . . . . . . . . . . . . . . . . . . 15<br> 3.3.1.4 Criteria for Dissimilar Metal Structures. . . . . . . . . . . 15<br>3.3.2 Other Electrical Criteria. . . . . . . . . . . . . . . . . . 15<br>3.3.2.1 Criteria for Lead. . . . . . . . . . . . . . . . . . . . . . 16<br> 3.3.2.2 NACE RP-02-85. . . . . . . . . . . . . . . . . . . . . . . . 16<br>3.4 Failure Rate Analysis. . . . . . . . . . . . . . . . . . . . 16<br>3.5 Nondestructive Testing of Facility. . . . . . . . . . . . . . 16<br>3.5.1 Visual Analysis. . . . . . . . . . . . . . . . . . . . . . . 16<br> 3.6 Consequences of Underprotection. . . . . . . . . . . . . . . 17<br>3.7 Consequences of Overprotection. . . . . . . . . . . . . . . . 18<br>3.7.1 Coating Disbondment. . . . . . . . . . . . . . . . . . . . . 18<br>3.7.2 Hydrogen Embrittlement. . . . . . . . . . . . . . . . . . . . 18<br> Section 4 CATHODIC PROTECTION SYSTEM DESIGN PRINCIPLES<br>4.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . 19<br>4.2 General Design Procedures. . . . . . . . . . . . . . . . . . 19<br>4.2.1 Drawings and Specifications. . . . . . . . . . . . . . . . . 19<br> 4.2.1.1 Drawings and Specifications for the Structure to<br>be Protected. . . . . . . . . . . . . . . . . . . . . . . . . 19<br>4.2.1.2 Site Drawings. . . . . . . . . . . . . . . . . . . . . . . . 19<br>4.2.2 Field Surveys. . . . . . . . . . . . . . . . . . . . . . . . 20<br> 4.2.2.1 Water Analysis. . . . . . . . . . . . . . . . . . . . . . . . 20<br>4.2.2.2 Soil Characteristics. . . . . . . . . . . . . . . . . . . . . 20<br>4.2.2.3 Current Requirement Tests. . . . . . . . . . . . . . . . . . 21<br> 4.2.2.4 Location of Other Structures in the Area. . . . . . . . . . . 22<br>4.2.2.5 Availability of ac Power. . . . . . . . . . . . . . . . . . . 22<br>4.2.3 Current Requirements. . . . . . . . . . . . . . . . . . . . . 22<br> 4.2.4 Choice of Sacrificial or Impressed Current<br>System. . . . . . . . . . . . . . . . . . . . . . . . . . . . 22<br>4.2.5 Basic Design Procedure for Sacrificial Anode<br>Systems. . . . . . . . . . . . . . . . . . . . . . . . . . 23<br> 4.2.6 Basic Design Procedure for Impressed Current<br>Systems. . . . . . . . . . . . . . . . . . . . . . . . . . 24<br>4.2.6.1 Total Current Determination. . . . . . . . . . . . . . . . . 24<br>4.2.6.2 Total Resistance Determination. . . . . . . . . . . . . . . . 26<br> 4.2.6.3 Voltage and Rectifier Determination. . . . . . . . . . . . . 27<br>4.2.7 Analysis of Design Factors. . . . . . . . . . . . . . . . . . 28<br>4.3 Determination of Field Data. . . . . . . . . . . . . . . . . 28<br> 4.3.1 Determination of Electrolyte Resistivity . . . . . . . . . . 29<br> 4.3.1.1 In Soils. . . . . . . . . . . . . . . . . . . . . . . . . . . 29<br>4.3.1.2 Liquids. . . . . . . . . . . . . . . . . . . . . . . . . . . 29<br> 4.3.2 Chemical Analysis of the Environment . . . . . . . . . . . . 31<br> 4.3.2.1 pH. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31<br>4.3.3 Coating Conductance. . . . . . . . . . . . . . . . . . . . . 31<br> 4.3.3.1 Short Line Method. . . . . . . . . . . . . . . . . . . . . . 33<br> 4.3.3.2 Long Line Method. . . . . . . . . . . . . . . . . . . . . . . 33<br>4.3.4 Continuity Testing. . . . . . . . . . . . . . . . . . . . . . 35<br> 4.3.4.1 Method 1. . . . . . . . . . . . . . . . . . . . . . . . . . . 35<br> 4.3.4.2 Method 2. . . . . . . . . . . . . . . . . . . . . . . . . . . 35<br>4.3.4.3 Method 3. . . . . . . . . . . . . . . . . . . . . . . . . . . 35<br> 4.3.5 Insulation Testing. . . . . . . . . . . . . . . . . . . . . . 35<br> 4.3.5.1 Buried Structures. . . . . . . . . . . . . . . . . . . . . . 35<br>4.3.5.2 Aboveground Structures. . . . . . . . . . . . . . . . . . . . 38<br> 4.4 Corrosion Survey Checklist. . . . . . . . . . . . . . . . . . 38<br> Section 5 PRECAUTIONS FOR CATHODIC PROTECTION SYSTEM DESIGN<br>5.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . 39<br>5.2 Excessive Currents and Voltages. . . . . . . . . . . . . . . 39<br> 5.2.1 Interference. . . . . . . . . . . . . . . . . . . . . . . . . 39<br> 5.2.1.1 Detecting Interference. . . . . . . . . . . . . . . . . . . . 41<br>5.2.1.2 Control of Interference - Anode Bed Location. . . . . . . . . 43<br> 5.2.1.3 Control of Interference - Direct Bonding. . . . . . . . . . . 43<br> 5.2.1.4 Control of Interference - Resistive Bonding. . . . . . . . . 45<br>5.2.1.5 Control of Interference - Sacrificial Anodes. . . . . . . . . 47<br> 5.2.2 Effects of High Current Density. . . . . . . . . . . . . . . 47<br> 5.2.3 Effects of Electrolyte pH. . . . . . . . . . . . . . . . . . 47<br>5.3 Hazards Associated with Cathodic Protection. . . . . . . . . 49<br>5.3.1 Explosive Hazards. . . . . . . . . . . . . . . . . . . . . . 49<br> 5.3.2 Bonding for Electrical Safety. . . . . . . . . . . . . . . . 49<br> 5.3.3 Induced Alternating Currents. . . . . . . . . . . . . . . . . 50<br>Section 6 IMPRESSED CURRENT SYSTEM<br>6.1 Advantages of Impressed Current Cathodic<br> Protection Systems. . . . . . . . . . . . . . . . . . . . . . 53<br> 6.2 Determination of Circuit Resistance. . . . . . . . . . . . . 53<br>6.2.1 Anode-to-Electrolyte Resistance. . . . . . . . . . . . . . . 53<br>6.2.1.1 Effect on System Design and Performance. . . . . . . . . . . 53<br> 6.2.1.2 Calculation of Anode-to-Electrolyte Resistance . . . . . . . 54<br> 6.2.1.3 Basic Equations . . . . . . . . . . . . . . . . . . . . . . . 54<br>6.2.1.4 Simplified Expressions for Common Situations. . . . . . . . . 55<br> 6.2.1.5 Field Measurement. . . . . . . . . . . . . . . . . . . . . . 57<br> 6.2.1.6 Effect of Backfill. . . . . . . . . . . . . . . . . . . . . . 58<br>6.2.2 Structure-to-Electrolyte Resistance. . . . . . . . . . . . . 59<br> 6.2.3 Connecting Cable Resistance. . . . . . . . . . . . . . . . . 59<br> 6.2.4 Resistance of Connections and Splices. . . . . . . . . . . . 59<br>6.3 Determination of Power Supply Requirements. . . . . . . . . . 59<br>6.4 Selection of Power Supply Type. . . . . . . . . . . . . . . . 60<br> 6.4.1 Rectifiers. . . . . . . . . . . . . . . . . . . . . . . . . . 60<br> 6.4.2 Thermoelectric Generators. . . . . . . . . . . . . . . . . . 60<br>6.4.3 Solar. . . . . . . . . . . . . . . . . . . . . . . . . . . . 60<br> 6.4.4 Batteries. . . . . . . . . . . . . . . . . . . . . . . . . . 60<br>6.4.5 Generators. . . . . . . . . . . . . . . . . . . . . . . . . . 60<br> 6.5 Rectifier Selection. . . . . . . . . . . . . . . . . . . . . 60<br>6.5.1 Rectifier Components. . . . . . . . . . . . . . . . . . . . . 61<br> 6.5.1.1 Transformer Component. . . . . . . . . . . . . . . . . . . . 61<br>6.5.1.2 Rectifying Elements. . . . . . . . . . . . . . . . . . . . . 61<br> 6.5.1.3 Overload Protection. . . . . . . . . . . . . . . . . . . . . 61<br> 6.5.1.4 Meters. . . . . . . . . . . . . . . . . . . . . . . . . . . . 63<br>6.5.2 Standard Rectifier Types . . . . . . . . . . . . . . . . . . 63<br> 6.5.2.1 Single-Phase Bridge. . . . . . . . . . . . . . . . . . . . . 63<br> 6.5.2.2 Single-Phase Center Tap. . . . . . . . . . . . . . . . . . . 63<br>6.5.2.3 Three-Phase Bridge. . . . . . . . . . . . . . . . . . . . . . 63<br> 6.5.2.4 Three-Phase Wye. . . . . . . . . . . . . . . . . . . . . . . 65<br> 6.5.2.5 Special Rectifier Types . . . . . . . . . . . . . . . . . . . 65<br>6.5.3 Rectifier Selection and Specifications. . . . . . . . . . . . 68<br> 6.5.3.1 Available Features. . . . . . . . . . . . . . . . . . . . . . 69<br> 6.5.3.2 Air Cooled Versus Oil Immersed. . . . . . . . . . . . . . . . 69<br>6.5.3.3 Selecting ac Voltage. . . . . . . . . . . . . . . . . . . . . 70<br> 6.5.3.4 dc Voltage and Current Output. . . . . . . . . . . . . . . . 70<br> </div><div style="text-align:left">6.5.3.5 Filters. . . . . . . . . . . . . . . . . . . . . . . . . . . 70<br></div><div style="text-align:left">6.5.3.6 Explosion Proof Rectifiers. . . . . . . . . . . . . . . . . . 70<br> 6.5.3.7 Lightning Arresters. . . . . . . . . . . . . . . . . . . . . 71<br>6.5.3.8 Selenium Versus Silicon Stacks. . . . . . . . . . . . . . . . 71<br>6.5.3.9 Other Options. . . . . . . . . . . . . . . . . . . . . . . . 71<br> 6.5.3.10 Rectifier Alternating Current Rating. . . . . . . . . . . . . 71<br>6.6 Anodes for Impressed Current Systems. . . . . . . . . . . . . 73<br>6.6.1 Graphite Anodes. . . . . . . . . . . . . . . . . . . . . . . 74<br> 6.6.1.1 Specifications. . . . . . . . . . . . . . . . . . . . . . . . 74<br>6.6.1.2 Available Sizes. . . . . . . . . . . . . . . . . . . . . . . 74<br>6.6.1.3 Characteristics. . . . . . . . . . . . . . . . . . . . . . . 77<br> 6.6.1.4 Operation. . . . . . . . . . . . . . . . . . . . . . . . . . 77<br>6.6.2 High Silicon Cast Iron. . . . . . . . . . . . . . . . . . . . 78<br>6.6.3 High Silicon Chromium Bearing Cast Iron<br>(HSCBCI). . . . . . . . . . . . . . . . . . . . . . . . . . . 78<br> 6.6.3.1 Specifications. . . . . . . . . . . . . . . . . . . . . . . . 78<br>6.6.3.2 Available Sizes. . . . . . . . . . . . . . . . . . . . . . . 79<br>6.6.3.3 Operation. . . . . . . . . . . . . . . . . . . . . . . . . . 79<br> 6.6.4 Aluminum. . . . . . . . . . . . . . . . . . . . . . . . . . . 79<br>6.6.5 Platinum. . . . . . . . . . . . . . . . . . . . . . . . . . . 79<br>6.6.6 Platinized Anodes. . . . . . . . . . . . . . . . . . . . . . 79<br> 6.6.6.1 Types. . . . . . . . . . . . . . . . . . . . . . . . . . . . 90<br>6.6.6.2 Operation. . . . . . . . . . . . . . . . . . . . . . . . . . 91<br>6.6.7 Alloyed Lead. . . . . . . . . . . . . . . . . . . . . . . . . 91<br> 6.7 Other System Components. . . . . . . . . . . . . . . . . . . 91<br>6.7.1 Connecting Cables. . . . . . . . . . . . . . . . . . . . . . 91<br>6.7.1.1 Factors to be Considered. . . . . . . . . . . . . . . . . . . 91<br> 6.7.1.2 Insulation. . . . . . . . . . . . . . . . . . . . . . . . . . 92<br> 6.7.1.3 Recommended Cables for Specific Applications. . . . . . . . . 93<br>6.7.1.4 Economic Wire Size. . . . . . . . . . . . . . . . . . . . . . 93<br> 6.7.2 Wire Splices and Connections. . . . . . . . . . . . . . . . . 94<br> 6.7.3 Test Stations. . . . . . . . . . . . . . . . . . . . . . . . 96<br>6.7.4 Bonds. . . . . . . . . . . . . . . . . . . . . . . . . . . . 96<br> 6.7.5 Insulating Joints. . . . . . . . . . . . . . . . . . . . . . 96<br>Section 7 SACRIFICIAL ANODE SYSTEM DESIGN<br> 7.1 Theory of Operation. . . . . . . . . . . . . . . . . . . . . 113<br>7.1.1 Advantages of Sacrificial Anode Cathodic<br> Protection Systems. . . . . . . . . . . . . . . . . . . . . . 113<br>7.1.2 Disadvantages of Sacrificial Anode Cathodic<br> Protection Systems. . . . . . . . . . . . . . . . . . . . . . 113<br>7.2 Sacrificial Anode Cathodic Protection System<br> DesignProcedures. . . . . . . . . . . . . . . . . . . . . . . 113<br>7.3 Determination of Current Required for<br> Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114<br>7.4 Determination of Anode Output. . . . . . . . . . . . . . . . 114<br> 7.4.1 Simplified Method for Common Situations. . . . . . . . . . . 114<br> 7.4.2 Determination of Output Using<br>Anode-to-Electrolyte Resistance. . . . . . . . . . . . . . . 114<br>7.4.2.1 Calculation of Anode-to-Electrolyte Resistance. . . . . . . . 114<br> 7.4.2.2 Determination of Structure-to-Electrolyte<br> Resistance. . . . . . . . . . . . . . . . . . . . . . . . . 115<br>7.4.2.3 Connecting Cable Resistance. . . . . . . . . . . . . . . . . 115<br>7.4.2.4 Resistance of Connections and Splices. . . . . . . . . . . . 115<br> 7.4.2.5 Total Circuit Resistance. . . . . . . . . . . . . . . . . . . 115<br> 7.4.2.6 Anode-to-Structure Potential. . . . . . . . . . . . . . . . . 115<br>7.4.2.7 Anode Output Current. . . . . . . . . . . . . . . . . . . . . 115<br> 7.4.3 Field Measurement of Anode Output. . . . . . . . . . . . . . 116<br> 7.5 Determination of Number of Anodes Required. . . . . . . . . . 116<br>7.6 Determination of Anode Life. . . . . . . . . . . . . . . . . 116<br> 7.7 Seasonal Variation in Anode Output. . . . . . . . . . . . . . 117<br>7.8 Sacrificial Anode Materials . . . . . . . . . . . . . . . . . 117<br> 7.8.1 Magnesium. . . . . . . . . . . . . . . . . . . . . . . . . . 117<br> 7.8.1.1 Composition. . . . . . . . . . . . . . . . . . . . . . . . . 118<br>7.8.1.2 Anode Efficiency. . . . . . . . . . . . . . . . . . . . . . . 118<br> 7.8.1.3 Potentials. . . . . . . . . . . . . . . . . . . . . . . . . . 119<br> 7.8.1.4 Sizes. . . . . . . . . . . . . . . . . . . . . . . . . . . . 119<br>7.8.1.5 Current Output. . . . . . . . . . . . . . . . . . . . . . . . 119<br> 7.8.1.6 Backfill. . . . . . . . . . . . . . . . . . . . . . . . . . . 119<br> 7.8.2 Zinc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119<br>7.8.2.1 Composition. . . . . . . . . . . . . . . . . . . . . . . . . 125<br> 7.8.2.2 Anode Efficiency. . . . . . . . . . . . . . . . . . . . . . . 125<br> 7.8.2.3 Potentials. . . . . . . . . . . . . . . . . . . . . . . . . . 125<br>7.8.2.4 Sizes. . . . . . . . . . . . . . . . . . . . . . . . . . . . 126<br> 7.8.2.5 Current Output. . . . . . . . . . . . . . . . . . . . . . . . 126<br> 7.8.2.6 Backfill. . . . . . . . . . . . . . . . . . . . . . . . . . . 126<br>7.8.3 Aluminum. . . . . . . . . . . . . . . . . . . . . . . . . . . 126<br> 7.8.3.1 Composition. . . . . . . . . . . . . . . . . . . . . . . . . 127<br> 7.8.3.2 Anode Efficiency. . . . . . . . . . . . . . . . . . . . . . . 127<br>7.8.3.3 Potentials. . . . . . . . . . . . . . . . . . . . . . . . . . 127<br> 7.8.3.4 Sizes. . . . . . . . . . . . . . . . . . . . . . . . . . . . 127<br> 7.8.3.5 Current Output. . . . . . . . . . . . . . . . . . . . . . . . 127<br>7.9 Other System Components . . . . . . . . . . . . . . . . . . . 127<br> 7.9.1 Connecting Wires. . . . . . . . . . . . . . . . . . . . . . . 127<br> 7.9.1.1 Determination of Connecting Wire Size and Type. . . . . . . . 133<br>7.9.2 Connections and Splices. . . . . . . . . . . . . . . . . . . 134<br> 7.9.3 Bonds and Insulating Joints. . . . . . . . . . . . . . . . . 134<br> 7.9.4 Test Station Location and Function. . . . . . . . . . . . . . 134<br>7.9.5 Backfill. . . . . . . . . . . . . . . . . . . . . . . . . . . 135<br> Section 8 TYPICAL CATHODIC PROTECTION<br>8.1 Diagrams of Cathodic Protection Systems. . . . . . . . . . . 137<br> Section 9 CATHODIC PROTECTION SYSTEM DESIGN EXAMPLES<br>9.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . 155<br> 9.2 Elevated Steel Water Tank. . . . . . . . . . . . . . . . . . 155<br>9.2.1 Design Data . . . . . . . . . . . . . . . . . . . . . . . . . 156<br> 9.2.2 Computations . . . . . . . . . . . . . . . . . . . . . . . . 156<br> 9.3 Elevated Water Tank (Where Ice is Expected). . . . . . . . . 173<br>9.3.1 Design Data . . . . . . . . . . . . . . . . . . . . . . . . . 176<br> 9.3.2 Computations . . . . . . . . . . . . . . . . . . . . . . . . 176<br> 9.4 Steel Gas Main. . . . . . . . . . . . . . . . . . . . . . . . 177<br>9.4.1 Design Data . . . . . . . . . . . . . . . . . . . . . . . . . 180<br> 9.4.2 Computations . . . . . . . . . . . . . . . . . . . . . . . . 180<br> 9.5 Gas Distribution System. . . . . . . . . . . . . . . . . . . 184<br>9.5.1 Design Data . . . . . . . . . . . . . . . . . . . . . . . . . 185<br> </div><div style="text-align:left">9.5.2 Computations . . . . . . . . . . . . . . . . . . . . . . . . 185<br> 9.6 Black Iron, Hot Water Storage Tank. . . . . . . . . . . . . . 187<br>9.6.1 Design Data . . . . . . . . . . . . . . . . . . . . . . . . . 188<br> 9.6.2 Computations . . . . . . . . . . . . . . . . . . . . . . . . 188<br> 9.7 Underground Steel Storage Tank. . . . . . . . . . . . . . . . 190<br>9.7.1 Design Data . . . . . . . . . . . . . . . . . . . . . . . . . 190<br> 9.7.2 Computations . . . . . . . . . . . . . . . . . . . . . . . . 192<br> 9.8 Heating Distribution System. . . . . . . . . . . . . . . . . 192<br>9.8.1 Design Data . . . . . . . . . . . . . . . . . . . . . . . . . 192<br> 9.8.2 Computations . . . . . . . . . . . . . . . . . . . . . . . . 193<br> 9.8.3 Groundbed Design . . . . . . . . . . . . . . . . . . . . . . 194<br>9.8.4 Rectifier Location. . . . . . . . . . . . . . . . . . . . . . 195<br> 9.9 Aircraft Multiple Hydrant Refueling System. . . . . . . . . . 195<br> 9.9.1 Design Data . . . . . . . . . . . . . . . . . . . . . . . . . 195<br>9.9.2 Computations. . . . . . . . . . . . . . . . . . . . . . . . . 196<br> 9.10 Steel Sheet Piling in Seawater (Galvanic nodes). . . . . . . 199<br> 9.10.1 Design Data . . . . . . . . . . . . . . . . . . . . . . . . . 199<br>9.10.2 Computations . . . . . . . . . . . . . . . . . . . . . . . . 201<br> 9.11 Steel Sheet Piling in Seawater (Impressed<br>Current<br>9.11.1 Design Data. . . . . . . . . . . . . . . . . . . . . . . . . 203<br> 9.11.2 Computations . . . . . . . . . . . . . . . . . . . . . . . . 203<br>9.12 Steel H Piling in Seawater (Galvanic Anodes). . . . . . . . . 207<br> 9.12.1 Design Data . . . . . . . . . . . . . . . . . . . . . . . . . 208<br> 9.12.2 Computations . . . . . . . . . . . . . . . . . . . . . . . . 208<br>9.13 Steel H Piling in Seawater (Impressed Current). . . . . . . . 210<br> 9.13.1 Design Data . . . . . . . . . . . . . . . . . . . . . . . . . 210<br> 9.13.2 Computations . . . . . . . . . . . . . . . . . . . . . . . . 210<br>Section 10 INSTALLATION AND CONSTRUCTION PRACTICES<br>10.1 Factors to Consider. . . . . . . . . . . . . . . . . . . . . 213<br> 10.2 Planning of Construction. . . . . . . . . . . . . . . . . . . 213<br> 10.3 Pipeline Coating. . . . . . . . . . . . . . . . . . . . . . . 213<br>10.3.1 Over-the-Ditch Coating. . . . . . . . . . . . . . . . . . . . 213<br> 10.3.2 Yard Applied Coating. . . . . . . . . . . . . . . . . . . . . 213<br> 10.3.3 Joint and Damage Repair. . . . . . . . . . . . . . . . . . . 214<br>10.3.4 Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . 214<br> 10.4 Coatings for Other Structures. . . . . . . . . . . . . . . . 214<br> 10.5 Pipeline Installation. . . . . . . . . . . . . . . . . . . . 214<br>10.5.1 Casings. . . . . . . . . . . . . . . . . . . . . . . . . . . 214<br> 10.5.2 Foreign Pipeline Crossings. . . . . . . . . . . . . . . . . . 215<br> 10.5.3 Insulating Joints. . . . . . . . . . . . . . . . . . . . . . 215<br>10.5.4 Bonds. . . . . . . . . . . . . . . . . . . . . . . . . . . . 216<br> 10.6 Electrical Connections. . . . . . . . . . . . . . . . . . . . 216<br> 10.7 Test Stations. . . . . . . . . . . . . . . . . . . . . . . . 216<br>10.8 Sacrificial Anode Installation. . . . . . . . . . . . . . . . 216<br> 10.8.1 Vertical. . . . . . . . . . . . . . . . . . . . . . . . . . . 216<br> 10.8.2 Horizontal. . . . . . . . . . . . . . . . . . . . . . . . . . 217<br>10.9 Impressed Current Anode Installation. . . . . . . . . . . . . 217<br> 10.9.1 Vertical. . . . . . . . . . . . . . . . . . . . . . . . . . . 219<br> 10.9.2 Horizontal. . . . . . . . . . . . . . . . . . . . . . . . . . 219<br>10.9.3 Deep Anode Beds. . . . . . . . . . . . . . . . . . . . . . . 219<br> 10.9.4 Other Anode Types. . . . . . . . . . . . . . . . . . . . . . 225<br> 10.9.5 Connections. . . . . . . . . . . . . . . . . . . . . . . . . 225<br>10.10 Impressed Current Rectifier Installation. . . . . . . . . . . 225<br> Section 11 SYSTEM CHECKOUT AND INITIAL ADJUSTMENTS<br>11.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . 229<br> 11.2 Initial Potential Survey. . . . . . . . . . . . . . . . . . . 229<br>11.3 Detection and Correction of Interference. . . . . . . . . . . 229<br> 11.4 Adjustment of Impressed Current Systems. . . . . . . . . . . 229<br> 11.4.1 Uneven Structure-To-Electrolyte Potentials. . . . . . . . . . 229<br>11.4.2 Rectifier Voltage and Current Capacity. . . . . . . . . . . . 230<br> 11.5 Adjustment of Sacrificial Anode Systems. . . . . . . . . . . 230<br> 11.5.1 Low Anode Current Levels. . . . . . . . . . . . . . . . . . . 230<br>11.5.2 Inadequate Protection at Designed Current Levels . . . . . . 230<br> Section 12 MAINTAINING CATHODIC PROTECTION<br>12.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . 231<br> 12.2 Required Periodic Monitoring and Maintenance. . . . . . . . . 231<br>12.3 Design Data Required for System Maintenance. . . . . . . . . 231<br> 12.3.1 Drawings. . . . . . . . . . . . . . . . . . . . . . . . . . . 231<br> 12.3.2 System Data. . . . . . . . . . . . . . . . . . . . . . . . . 231<br>12.3.2.1 Design Potentials. . . . . . . . . . . . . . . . . . . . . . 231<br> 12.3.2.2 Current Output. . . . . . . . . . . . . . . . . . . . . . . . 231<br> 12.3.2.3 System Settings and Potential Readings. . . . . . . . . . . . 231<br>12.3.2.4 Rectifier Instructions. . . . . . . . . . . . . . . . . . . . 232<br> 12.4 Basic Maintenance Requirements. . . . . . . . . . . . . . . . 232<br> 12.5 Guidance for Maintenance . . . . . . . . . . . . . . . . . . 232<br>12.5.1 Agency Maintenance and Operations Manuals. . . . . . . . . . 232<br> 12.5.2 DOT Regulations. . . . . . . . . . . . . . . . . . . . . . . 235<br> 12.5.3 NACE Standards. . . . . . . . . . . . . . . . . . . . . . . . 235<br>Section 13 ECONOMIC ANALYSIS<br>13.1 Importance of Economic Analysis. . . . . . . . . . . . . . . 237<br> 13.2 Economic Analysis Process. . . . . . . . . . . . . . . . . . 237<br> 13.2.1 Define the Objective. . . . . . . . . . . . . . . . . . . . . 237<br>13.2.2 Generate Alternatives. . . . . . . . . . . . . . . . . . . . 238<br> 13.2.3 Formulate Assumptions. . . . . . . . . . . . . . . . . . . . 238<br> 13.2.4 Determine Costs and Benefits. . . . . . . . . . . . . . . . . 238<br>13.2.4.1 Costs. . . . . . . . . . . . . . . . . . . . . . . . . . . . 238<br> 13.2.4.2 Benefits. . . . . . . . . . . . . . . . . . . . . . . . . . . 239<br> 13.2.5 Compare Costs and Benefits and Rank<br>Alternatives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239<br>13.2.6 Perform Sensitivity Analysis. . . . . . . . . . . . . . . . . 239<br> 13.3 Design of Cathodic Protection Systems. . . . . . . . . . . . 239<br> 13.4 Economic Analysis - Example 1 . . . . . . . . . . . . . . . . 240<br>13.4.1 Objective. . . . . . . . . . . . . . . . . . . . . . . . . . 240<br> 13.4.2 Alternatives . . . . . . . . . . . . . . . . . . . . . . . . 240<br> 13.4.3 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . 240<br>13.4.4 Cost/Benefit Analysis . . . . . . . . . . . . . . . . . . . . 240<br> 13.4.4.1 Cost - Alternative 1--Steel Line Without<br>Cathodic Protection. . . . . . . . . . . . . . . . . . . . . 240<br> 13.4.4.2 Cost - Alternative 2--Steel Line with Cathodic<br>Protection. . . . . . . . . . . . . . . . . . . . . . . . . . 242<br> 13.4.4.3 Cost - Alternative 3--Plastic Line. . . . . . . . . . . . . . 242<br>13.4.4.4 Benefits. . . . . . . . . . . . . . . . . . . . . . . . . . . 243<br> 13.4.5 Compare Costs/Benefits . . . . . . . . . . . . . . . . . . . 243<br> 13.5 Economic Analysis - Example 2 . . . . . . . . . . . . . . . . 243<br>13.5.1 Objective. . . . . . . . . . . . . . . . . . . . . . . . . . 243<br> 13.5.2 Alternative . . . . . . . . . . . . . . . . . . . . . . . . . 243<br> 13.5.3 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . 243<br>13.5.4 Cost/Benefit Analysis . . . . . . . . . . . . . . . . . . . . 244<br> 13.5.4.1 Cost - Alternative 1--Steel Line Without<br>Cathodic Protection. . . . . . . . . . . . . . . . . . . . . 244<br> 13.5.4.2 Cost - Alternative 2--Steel Line With Cathodic<br>Protection. . . . . . . . . . . . . . . . . . . . . . . . . . 245<br> 13.5.4.3 Benefits. . . . . . . . . . . . . . . . . . . . . . . . . . . 246<br>13.5.5 Compare Costs/Benefits . . . . . . . . . . . . . . . . . . . 246<br> 13.5.6 Conclusions and Recommendations. . . . . . . . . . . . . . . 247<br> 13.6 Economic Analysis - Example 3 . . . . . . . . . . . . . . . . 247<br>13.6.1 Objective. . . . . . . . . . . . . . . . . . . . . . . . . . 247<br> 13.6.2 Alternatives . . . . . . . . . . . . . . . . . . . . . . . . 247<br> 13.6.3 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . 247<br>13.6.4 Cost/Benefit Analysis . . . . . . . . . . . . . . . . . . . . 247<br> 13.6.4.1 Cost - Alternative 1--Impressed Current Cathodic<br>Protection. . . . . . . . . . . . . . . . . . . . . . . . . 247<br> 13.6.4.2 Cost - Alternative 2--Galvanic Anode System. . . . . . . . . 248<br>13.6.5 Compare Costs/Benefits . . . . . . . . . . . . . . . . . . . 249<br> 13.7 Economic Analysis - Example 4 . . . . . . . . . . . . . . . . 249<br> 13.7.1 Objective . . . . . . . . . . . . . . . . . . . . . . . . . . 249<br>13.7.2 Alternatives . . . . . . . . . . . . . . . . . . . . . . . . 249<br> 13.7.3 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . 249<br> 13.7.4 Cost/Benefit Analysis . . . . . . . . . . . . . . . . . . . . 249<br>13.7.4.1 Cost - Alternative 1--Cathodic Protection System<br>Maintenance Continued. . . . . . . . . . . . . . . . . . . 249<br> 13.7.4.2 Cost - Alternative 2--Cathodic Protection System<br> Maintenance Discontinued. . . . . . . . . . . . . . . . . . 250<br>13.7.5 Compare Benefits and Costs . . . . . . . . . . . . . . . . . 251<br>13.8 Economic Analysis Goal. . . . . . . . . . . . . . . . . . . . 251<br> Section 14 CORROSION COORDINATING COMMITTEE PARTICIPATION<br> 14.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . 253<br>14.2 Functions of Corrosion Coordinating Committees. . . . . . . . 253<br>14.3 Operation of the Committees. . . . . . . . . . . . . . . . . 253<br> 14.4 Locations of Committees. . . . . . . . . . . . . . . . . . . 253<br>APPENDIX<br>APPENDIX A UNDERGROUND CORROSION SURVEY CHECKLIST . . . . . . . . . . . 255<br>B ECONOMIC LIFE GUIDELINES . . . . . . . . . . . . . . . . . . 265<br> C PROJECT YEAR DISCOUNT FACTORS . . . . . . . . . . . . . . . . 267<br>D PRESENT VALUE FORMULAE . . . . . . . . . . . . . . . . . . . 269<br>E DOT REGULATIONS . . . . . . . . . . . . . . . . . . . . . . . 271<br></div><div style="text-align:left"> Figure 1 The Electrochemical Cell . . . . . . . . . . . . . . . . . . 6<br>2 Corrosion Cell - Zinc and Platinum<br>in Hydrochloric Acid . . . . . . . . . . . . . . . . . . . 6<br>3 Cathodic Protection Cell . . . . . . . . . . . . . . . . . . 7<br> 4 Hydraulic Analogy of Cathodic Protection . . . . . . . . . . 7<br>5 Sacrificial Anode Cathodic Protection/Impressed<br>Current Cathodic Protection . . . . . . . . . . . . . . . . 9<br>6 Structure-to Electrolyte Potential Measurement . . . . . . . 14<br> 7 Failure Rate Versus Time . . . . . . . . . . . . . . . . . . 17<br>8 Temporary Cathodic Protection System for<br>Determining Current Requirements . . . . . . . . . . . . . 23<br>9 4-Pin Soil Resistivity Measurement . . . . . . . . . . . . . 30<br> 10 Soil Box for Determination of Resistivity . . . . . . . . . . 30<br>11 pH Meter . . . . . . . . . . . . . . . . . . . . . . . . . . 32<br>12 Antimony Electrode Potential Versus pH . . . . . . . . . . . 32<br>13 Coating Conductance - Short Line Method . . . . . . . . . . . 34<br> 14 Coating Conductance - Long Line Method . . . . . . . . . . . 34<br>15 Continuity Testing - Potential Method . . . . . . . . . . . . 36<br>16 Continuity Testing - Potential Drop Method . . . . . . . . . 36<br>17 Continuity Testing - Pipe Locator Method . . . . . . . . . . 37<br> 18 Insulation Testing - Two-Wire Test Station . . . . . . . . . 37<br>19 Interference from Impressed Current<br>Cathodic Protection System . . . . . . . . . . . . . . . . 40<br>20 Interference Due to Potential Gradients . . . . . . . . . . . 41<br> 21 Interference Testing . . . . . . . . . . . . . . . . . . . . 42<br>22 Plot of Potentials from Interference Test . . . . . . . . . . 42<br>23 Measurement of Current Flow in Structure . . . . . . . . . . 44<br>24 Correction of Interferencce - Direct Bonding . . . . . . . . 44<br> 25 Correction of Interference - Resistive Bonding . . . . . . . 45<br>26 Effects of Bonding on Interference Test<br>Potentials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46<br>27 Bonding for Continuity . . . . . . . . . . . . . . . . . . . 48<br> 28 Control of Interference - Sacrificial Anode . . . . . . . . . 48<br>29 Interference Due to Cathodic Protection of<br>Quaywall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50<br>30 Correction of Interference - Bonding . . . . . . . . . . . . 51<br> 31 Equavalent Cathodic Protection Circuit . . . . . . . . . . . 54<br>32 Single-Phase - Full-Wave Bridge Rectifier . . . . . . . . . . 62<br>33 Full-Wave Rectified Current . . . . . . . . . . . . . . . . . 64<br>34 Single-Phase - Center Tap Circuit . . . . . . . . . . . . . . 64<br> 35 Three-Phase Bridge Circuit . . . . . . . . . . . . . . . . . 65<br>36 Three-Phase Wye Circuit . . . . . . . . . . . . . . . . . . . 66<br>37 Half-Wave Rectified Current . . . . . . . . . . . . . . . . . 66<br>38 Constant Current Rectifier . . . . . . . . . . . . . . . . . 67<br> 39 Constant Potential Rectifier . . . . . . . . . . . . . . . . 67<br>40 Multicircuit Constant Current Rectifier . . . . . . . . . . . 68<br>41 Efficiency Versus Voltage - Selenium Stacks . . . . . . . . . 72<br>42 Efficiency Versus Voltage - Silicon Stacks . . . . . . . . . 73<br> 43 Anode-to-Cable Connection - Graphite Anode . . . . . . . . . 75<br>44 Center Connected Graphite Anode . . . . . . . . . . . . . . . 76<br>45 Duct Anode . . . . . . . . . . . . . . . . . . . . . . . . . 83<br>46 Button Anode . . . . . . . . . . . . . . . . . . . . . . . . 83<br> 47 Bridge Deck Anode - Type I . . . . . . . . . . . . . . . . . 84<br>48 Bridge Deck Anode - Type II . . . . . . . . . . . . . . . . . 85<br>49 Tubular Anode . . . . . . . . . . . . . . . . . . . . . . . . 86<br>50 Anode to Cable Connection - Epoxy Seal . . . . . . . . . . . 87<br> 51 Anode to Cable Connection - Teflon Seal . . . . . . . . . . . 88<br>52 Center Connected High Silicon Chromium<br>Bearing Cast Iron Anode . . . . . . . . . . . . . . . . . . 89<br>53 Typical Platinized Anode . . . . . . . . . . . . . . . . . . 90<br> 54 Flush-Mounted Potential Test Station . . . . . . . . . . . . 97<br>55 Soil Contact Test Station . . . . . . . . . . . . . . . . . . 98<br>56 IR Drop Test Station . . . . . . . . . . . . . . . . . . . . 99<br>57 Insulating Flange Test Station (Six-Wire) . . . . . . . . . . 100<br> 58 Wiring for Casing Isolation Test Station . . . . . . . . . . 101<br>59 Bond Test Station . . . . . . . . . . . . . . . . . . . . . . 101<br>60 Anode Balancing Resistors . . . . . . . . . . . . . . . . . . 102<br>61 Bonding of a Dresser-Style Coupling . . . . . . . . . . . . . 103<br> 62 Bonding Methods for Cast Iron Bell-and-Spigot<br>Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104<br>63 Isolating a Protected Line from an Unprotected<br>Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105<br> 64 Electrical Bond . . . . . . . . . . . . . . . . . . . . . . . 106<br>65 Thermosetting-Resin Pipe Connection . . . . . . . . . . . . . 106<br>66 Clamp Type Bonding Joint . . . . . . . . . . . . . . . . . . 107<br>67 Underground Splice . . . . . . . . . . . . . . . . . . . . . 108<br> 68 Welded Type Bonding Joint for Slip-On<br>Pipe Installed Aboveground . . . . . . . . . . . . . . . . 109<br>69 Test Box for an Insulating Fitting . . . . . . . . . . . . . 110<br>70 Steel Insulating Joint Details for Flanged<br> Pipe Installed Below Grade . . . . . . . . . . . . . . . . 111<br>71 Steel Insulating Joint Details for Aboveground<br>Flanged Pipe . . . . . . . . . . . . . . . . . . . . . . . 112<br>72 Insulating Joint Details for Screwed Pipe<br> Connections . . . . . . . . . . . . . . . . . . . . . . . . 112<br>73 Efficiency Versus Current Density - Magnesium<br>Anodes . . . . . . . . . . . . . . . . . . . . . . . . . . 118<br>74 Aluminum Alloy Bracelet Anodes . . . . . . . . . . . . . . . 133<br> 75 Current-Potential Test Station . . . . . . . . . . . . . . . 135<br>76 Typical Building Underground Heat & Water Lines . . . . . . . 138<br>77 Impressed Current Point Type Cathodic Protection<br>for Aircraft Hydrant Refueling System . . . . . . . . . . . . 138<br> 78 Galvanic Anode Type Cathodic Protection for<br>Coated Underground Sewage Lift Station . . . . . . . . . . . 139<br>79 Zinc Anode on Reinforced Concrete Block . . . . . . . . . . . 140<br>80 Radiant Heat or Snow-Melting Piping . . . . . . . . . . . . . 141<br> 81 Cathodic Protection of Foundation Piles . . . . . . . . . . . 142<br>82 Impressed Current Cathodic Protection for<br>Existing On-Grade Storage Tank . . . . . . . . . . . . . . 142<br>83 Impressed Current Cathodic Protection with<br> Horizontal Anodes for On-Grade Storage Tank - New<br>Installation . . . . . . . . . . . . . . . . . . . . . . . 143<br>84 On-Grade Fresh Water Tank Using Suspended Anodes . . . . . . 144<br>85 Open Water Box Cooler . . . . . . . . . . . . . . . . . . . . 144<br> 86 Horizontal Hot Water Tank - Magnesium Anode<br>Installation . . . . . . . . . . . . . . . . . . . . . . . 145<br>87 Impressed Current Cathodic Protection System for<br>Sheet Piling for Wharf Construction . . . . . . . . . . . . 146<br> 88 Suspended Anode Cathodic Protection for H-Piling<br>in Seawater . . . . . . . . . . . . . . . . . . . . . . . . . 146<br>89 Cathodic Protection for H-Piling in Seawater . . . . . . . . 147<br>90 Cellular Earth Fill Pier Supports . . . . . . . . . . . . . . 148<br> 91 Elevated Fresh Water Tank Using Suspended Anodes . . . . . . 149<br>92 Cathodic Protection of Tanks using Rigid<br>Floor-Mounted Anodes . . . . . . . . . . . . . . . . . . . 150<br>93 Cathodic Protection of Hydraulic Elevator<br> Cylinders . . . . . . . . . . . . . . . . . . . . . . . . . . 151<br>94 Hydraulic Hoist Cylinder . . . . . . . . . . . . . . . . . . 152<br>95 Typical Cathodic Protection of Underground Tank<br>Farm . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153<br> 96 Gasoline Service Station System . . . . . . . . . . . . . . . 154<br>97 Segmented Elevated Tank for Area Calculations . . . . . . . . 157<br>98 Anode Spacing for Elevated Steel Water Tank . . . . . . . . . 160<br>99 Anode Suspension Arrangement for Elevated<br> Steel Water Tank . . . . . . . . . . . . . . . . . . . . . 162<br>100 Equivalent Diameter for Anodes in a<br>Circle in Water Tank . . . . . . . . . . . . . . . . . . . 163<br>101 Fringe Factor for Stub Anodes . . . . . . . . . . . . . . . . 164<br> 102 Elevated Steel Water Tank Showing Rectifier and<br>Anode Arrangement . . . . . . . . . . . . . . . . . . . . . 172<br>103 Hand Hole and Anode Suspension Detail for<br>Elevated Water Tank . . . . . . . . . . . . . . . . . . . . . . . . . 174<br> 104 Riser Anode Suspension Detail for Elevated Water<br>Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174<br>105 Dimensions: Elevated Steel Water Tank . . . . . . . . . . . 175<br>106 Cathodic Protection for Tanks Using Rigid Mounted . . . . . . 178<br> Button-Type Anodes and Platinized Titanium Wire<br>107 Cathodic Protection System for Gas Main . . . . . . . . . . . 179<br>108 Layout of Gas Piping in Residential District . . . . . . . . 184<br>109 Cathodic Protection for Black Iron, Hot Water<br> Storage Tank . . . . . . . . . . . . . . . . . . . . . . . . 187<br>110 Galvanic Anode Cathodic Protection of<br>Underground Steel Storage Tank . . . . . . . . . . . . . . . 191<br>111 Impressed Current Cathodic Protection for<br> Heating Conduit System . . . . . . . . . . . . . . . . . . . . . . . . 193<br>112 Galvanic Anode Cathodic Protection for Hydrant<br>Refueling System . . . . . . . . . . . . . . . . . . . . . . 197<br>113 Galvanic Anode Cathodic Protection System for<br> Steel Sheet Piling Bulkhead . . . . . . . . . . . . . . . . . 200<br>114 Impressed Current Cathodic Protection System<br>for Steel Sheet Piling Bulkhead . . . . . . . . . . . . . . . 207<br>115 Pier Supported by H Piling for Para. 9.12 . . . . . . . . . . 208<br> 116 Test Station for Under-Road Casing Isolation . . . . . . . . 215<br>117 Vertical Sacrificial Anode Installation . . . . . . . . . . . 217<br>118 Horizontal Sacrificial Anode Installation When<br>Obstruction is Encountered . . . . . . . . . . . . . . . . 218<br> 119 Horizontal Sacrificial Anode Installation -<br>Limited Right-of-Way . . . . . . . . . . . . . . . . . . . 218<br>120 Vertical HSCBCI Anode Installation . . . . . . . . . . . . . 220<br>121 Vertical HSCBCI Anode Installation With Packaged<br> Backfill . . . . . . . . . . . . . . . . . . . . . . . . . 221<br>122 Horizontal HSCBCI Anode Installation . . . . . . . . . . . . 222<br>123 Typical Deep Well Anode Cathodic Protection<br>Installation . . . . . . . . . . . . . . . . . . . . . . . 223<br> 124 Deep Anode Installation Details . . . . . . . . . . . . . . . 224<br>125 Typical Pole-Mounted Cathodic Protection<br>Rectifier Installation . . . . . . . . . . . . . . . . . . 226<br>126 Typical Pad-Mounted Cathodic Protection<br> Rectifier Installation . . . . . . . . . . . . . . . . . . 227<br>127 Form for Recording and Reporting Monthly<br>Rectifier Readings . . . . . . . . . . . . . . . . . . . . . 233<br>128 Form for Recording and Reporting Quarterly<br> Structure-to-Electrode Potentials . . . . . . . . . . . . 234<br>TABLES<br>Table 1 Current Requirements for Cathodic Protection of<br>Bare Steel . . . . . . . . . . . . . . . . . . . . . . . . . 20<br>2 Current Requirements for Cathodic Protection of<br> Coated Steel . . . . . . . . . . . . . . . . . . . . . . . 21<br>3 Galvanic Anode Size Factors . . . . . . . . . . . . . . . . . 25<br>4 Structure Potential Factor . . . . . . . . . . . . . . . . . 26<br>5 Adjusting Factor for Multiple Anodes (F) . . . . . . . . . . 27<br> 6 Corrections Factors - Short Line Coating Conductance . . . . 33<br>7 Results of Structure-to-Electrolyte<br>Potential Measurements . . . . . . . . . . . . . . . . . . 43<br>8 Standard HSCBCI Anodes . . . . . . . . . . . . . . . . . . . 80<br> 9 Special HSCBCI Anodes . . . . . . . . . . . . . . . . . . . . 82<br>10 Standard Wire Characteristics . . . . . . . . . . . . . . . . 92<br>11 M Factors for Determining Economic Wire Size<br>(Cost of losses in 100 feet of copper cable<br> at 1 cent per kWhr) . . . . . . . . . . . . . . . . . . . . 95<br>12 Standard Alloy Magnesium Anodes - Standard<br>Sizes for Use in Soil . . . . . . . . . . . . . . . . . . . 120<br>13 Standard Alloy Magnesium Anodes - Standard<br> Sizes for Use in Water . . . . . . . . . . . . . . . . . . 121<br>14 Standard Alloy Magnesium Anodes -Standard<br>Sizes for Condensors and Heat Exchangers . . . . . . . . . 121<br>15 Standard Alloy Magnesium Anodes - Elongated . . . . . . . . . 122<br> 16 High Potential Alloy Magnesium Anodes - Standard<br>Sizes for Soil and Water . . . . . . . . . . . . . . . . . 122<br>17 Standard Alloy Magnesium Anodes - Standard Size<br>Extruded Rod for Water Tanks and Water Heaters . . . . . . 123<br> 18 Zinc Anodes - Standard Sizes for Underground or<br>Fresh Water . . . . . . . . . . . . . . . . . . . . . . . . 123<br>19 Zinc Anodes - Special Sizes for Underground or<br>Fresh Water . . . . . . . . . . . . . . . . . . . . . . . . 124<br> 20 Zinc Anodes - Standard Sizes for Use in Seawater . . . . . . 124<br>21 Zinc Anodes - Special Sizes for Use in Seawater . . . . . . . 125<br>22 Aluminum Pier and Piling Anodes - Standard Sizes . . . . . . 128<br>23 Type I Aluminum Alloy Anodes - Standard Sizes<br> for Offshore Use . . . . . . . . . . . . . . . . . . . . . 129<br>24 Type III Aluminum Alloy Anodes for Offshore Use . . . . . . . 130<br>25 Aluminum Alloy Hull Anodes - Standard Sizes<br>(Types I, II, and III) . . . . . . . . . . . . . . . . . . 132<br> 26 Aluminum Alloy Bracelet Anode - Standard Sizes . . . . . . . 133<br>27 Technical Data - Commonly Used HSCBCI Anodes . . . . . . . . 161<br>REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287<br> GLOSSARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289<br></div><br></div><div style="text-align:center"><div style="color:rgb(255,0,0);text-align:center"><b>Read More !<br></b></div> <b style="color:rgb(255,0,0)">Free Download it !</b></div> <div><div dir="ltr"><div style="text-align:center"><a href="http://goo.gl/jbDW9" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/b_dl.gif"></a><a href="http://marinenotesonline.blogspot.in/p/buy-marine-notes.html" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/b_buy.gif"></a><font 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</center></div>Marine Noteshttp://www.blogger.com/profile/14270820931606062583noreply@blogger.com0tag:blogger.com,1999:blog-838411897140673717.post-28734322916610546672013-01-27T03:02:00.001+05:302013-01-27T03:02:15.651+05:30Mechanical Engineer's Handbook by Dan B. Marghitu<div dir="ltr"><b style="text-align:center">Dan B. Marghitu Mechanical Engineers Handbook (marinenotesonline)</b><br><div class="gmail_quote"><div dir="ltr"><div style="text-align:center"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5mKmiiuZay_WYfqRfHecNY4pDjml1WC2X3DVPL6ljDzB-R6RZg-c-eD0wkwomo_0bBpFK7NUphyyrWba3s7momLNrWw8oH6bKlcPWqHLTzCii92bmwVtXQYvFkibJkTvjEOil_FC8LQX2/s1600/Dan+B.+Marghitu+Mechanical+Engineers+Handbook-731854.jpg" target="_blank"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5mKmiiuZay_WYfqRfHecNY4pDjml1WC2X3DVPL6ljDzB-R6RZg-c-eD0wkwomo_0bBpFK7NUphyyrWba3s7momLNrWw8oH6bKlcPWqHLTzCii92bmwVtXQYvFkibJkTvjEOil_FC8LQX2/s320/Dan+B.+Marghitu+Mechanical+Engineers+Handbook-731854.jpg" border="0" alt=""></a><br> <b>Dan B. Marghitu Mechanical Engineers Handbook (marinenotesonline)</b><br> <b>Mechanical Engineer's Handbook by Dan B. Marghitu</b><br>Department of Mechanical Engineering, Auburn University,<br>Auburn, Alabama<br> <br><div style="text-align:left">Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii<br> Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv<br> <br>CHAPTER 1 Statics<br>Dan B. Marghitu, Cristian I. Diaconescu, and Bogdan O. Ciocirlan<br>1. Vector Algebra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2<br> 1.1 Terminology and Notation . . . . . . . . . . . . . . . . . . . . . . . . . . 2<br> 1.2 Equality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4<br>1.3 Product of a Vector and a Scalar . . . . . . . . . . . . . . . . . . . . . . 4<br> 1.4 Zero Vectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4<br> 1.5 Unit Vectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4<br>1.6 Vector Addition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5<br> 1.7 Resolution of Vectors and Components . . . . . . . . . . . . . . . . . . 6<br> 1.8 Angle between Two Vectors . . . . . . . . . . . . . . . . . . . . . . . . . 7<br>1.9 Scalar (Dot) Product of Vectors . . . . . . . . . . . . . . . . . . . . . . . 9<br> 1.10 Vector (Cross) Product of Vectors . . . . . . . . . . . . . . . . . . . . . . 9<br> 1.11 Scalar Triple Product of Three Vectors . . . . . . . . . . . . . . . . . . 11<br>1.12 Vector Triple Product of Three Vectors . . . . . . . . . . . . . . . . . . 11<br> 1.13 Derivative of a Vector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12<br> <br>2. Centroids and Surface Properties . . . . . . . . . . . . . . . . . . . . . . . . . . 12<br>2.1 Position Vector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12<br> 2.2 First Moment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13<br> 2.3 Centroid of a Set of Points . . . . . . . . . . . . . . . . . . . . . . . . . . 13<br>2.4 Centroid of a Curve, Surface, or Solid . . . . . . . . . . . . . . . . . . . 15<br> 2.5 Mass Center of a Set of Particles . . . . . . . . . . . . . . . . . . . . . . 16<br> 2.6 Mass Center of a Curve, Surface, or Solid . . . . . . . . . . . . . . . . 16<br>2.7 First Moment of an Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17<br> 2.8 Theorems of Guldinus±Pappus . . . . . . . . . . . . . . . . . . . . . . . 21<br> 2.9 Second Moments and the Product of Area . . . . . . . . . . . . . . . . 24<br>2.10 Transfer Theorem or Parallel-Axis Theorems . . . . . . . . . . . . . . 25<br> 2.11 Polar Moment of Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27<br> 2.12 Principal Axes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28<br><br>3. Moments and Couples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30<br> 3.1 Moment of a Bound Vector about a Point . . . . . . . . . . . . . . . . 30<br> 3.2 Moment of a Bound Vector about a Line . . . . . . . . . . . . . . . . . 31<br>3.3 Moments of a System of Bound Vectors . . . . . . . . . . . . . . . . . 32<br> </div><div style="text-align:left">3.4 Couples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34<br> 3.5 Equivalence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35<br> 3.6 Representing Systems by Equivalent Systems . . . . . . . . . . . . . . 36<br><br>4. Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40<br> 4.1 Equilibrium Equations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40<br> 4.2 Supports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42<br>4.3 Free-Body Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44<br> 5. Dry Friction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46<br> 5.1 Static Coef®cient of Friction . . . . . . . . . . . . . . . . . . . . . . . . . . 47<br>5.2 Kinetic Coef®cient of Friction . . . . . . . . . . . . . . . . . . . . . . . . . 47<br> 5.3 Angles of Friction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48<br> <br>References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49<br><br>CHAPTER 2 Dynamics<br> Dan B. Marghitu, Bogdan O. Ciocirlan, and Cristian I. Diaconescu<br>1. Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52<br> 1.1 Space and Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52<br> 1.2 Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52<br>1.3 Angular Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53<br> <br>2. Kinematics of a Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54<br> 2.1 Position, Velocity, and Acceleration of a Point. . . . . . . . . . . . . . 54<br>2.2 Angular Motion of a Line. . . . . . . . . . . . . . . . . . . . . . . . . . . . 55<br> 2.3 Rotating Unit Vector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56<br> 2.4 Straight Line Motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57<br>2.5 Curvilinear Motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58<br> 2.6 Normal and Tangential Components . . . . . . . . . . . . . . . . . . . . 59<br> 2.7 Relative Motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73<br><br>3. Dynamics of a Particle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74<br> 3.1 Newton's Second Law. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74<br> 3.2 Newtonian Gravitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75<br>3.3 Inertial Reference Frames . . . . . . . . . . . . . . . . . . . . . . . . . . . 75<br> 3.4 Cartesian Coordinates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76<br> 3.5 Normal and Tangential Components . . . . . . . . . . . . . . . . . . . . 77<br>3.6 Polar and Cylindrical Coordinates . . . . . . . . . . . . . . . . . . . . . . 78<br> 3.7 Principle of Work and Energy . . . . . . . . . . . . . . . . . . . . . . . . 80<br> 3.8 Work and Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81<br>3.9 Conservation of Energy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84<br> 3.10 Conservative Forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85<br> 3.11 Principle of Impulse and Momentum. . . . . . . . . . . . . . . . . . . . 87<br>3.12 Conservation of Linear Momentum . . . . . . . . . . . . . . . . . . . . . 89<br> 3.13 Impact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90<br> 3.14 Principle of Angular Impulse and Momentum . . . . . . . . . . . . . . 94<br><br>4. Planar Kinematics of a Rigid Body . . . . . . . . . . . . . . . . . . . . . . . . . . 95<br> 4.1 Types of Motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95<br> 4.2 Rotation about a Fixed Axis . . . . . . . . . . . . . . . . . . . . . . . . . . 96<br>4.3 Relative Velocity of Two Points of the Rigid Body . . . . . . . . . . . 97<br> 4.4 Angular Velocity Vector of a Rigid Body. . . . . . . . . . . . . . . . . . 98<br> 4.5 Instantaneous Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100<br>4.6 Relative Acceleration of Two Points of the Rigid Body . . . . . . . 102<br> 4.7 Motion of a Point That Moves Relative to a Rigid Body . . . . . . 103<br> <br>5. Dynamics of a Rigid Body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111<br>5.1 Equation of Motion for the Center of Mass. . . . . . . . . . . . . . . 111<br> 5.2 Angular Momentum Principle for a System of Particles. . . . . . . 113<br> 5.3 Equation of Motion for General Planar Motion . . . . . . . . . . . . 115<br>5.4 D'Alembert's Principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117<br> References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117<br> <br>CHAPTER 3 Mechanics of Materials<br>Dan B. Marghitu, Cristian I. Diaconescu, and Bogdan O. Ciocirlan<br>1. Stress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120<br> 1.1 Uniformly Distributed Stresses . . . . . . . . . . . . . . . . . . . . . . . 120<br> 1.2 Stress Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120<br>1.3 Mohr's Circle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121<br> 1.4 Triaxial Stress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125<br> 1.5 Elastic Strain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127<br>1.6 Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128<br> 1.7 Shear and Moment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131<br> 1.8 Singularity Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132<br>1.9 Normal Stress in Flexure. . . . . . . . . . . . . . . . . . . . . . . . . . . 135<br> 1.10 Beams with Asymmetrical Sections . . . . . . . . . . . . . . . . . . . . 139<br> 1.11 Shear Stresses in Beams . . . . . . . . . . . . . . . . . . . . . . . . . . . 140<br>1.12 Shear Stresses in Rectangular Section Beams . . . . . . . . . . . . . 142<br> 1.13 Torsion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143<br> 1.14 Contact Stresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147<br><br>2. De¯ection and Stiffness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149<br> 2.1 Springs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150<br> 2.2 Spring Rates for Tension, Compression, and Torsion . . . . . . . . 150<br>2.3 De¯ection Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152<br> 2.4 De¯ections Analysis Using Singularity Functions . . . . . . . . . . . 153<br> 2.5 Impact Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157<br>2.6 Strain Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160<br> 2.7 Castigliano's Theorem . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163<br> 2.8 Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165<br>2.9 Long Columns with Central Loading . . . . . . . . . . . . . . . . . . . 165<br> 2.10 Intermediate-Length Columns with Central Loading. . . . . . . . . 169<br> 2.11 Columns with Eccentric Loading . . . . . . . . . . . . . . . . . . . . . 170<br>2.12 Short Compression Members . . . . . . . . . . . . . . . . . . . . . . . . 171<br> <br>3. Fatigue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173<br> 3.1 Endurance Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173<br>3.2 Fluctuating Stresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178<br> 3.3 Constant Life Fatigue Diagram . . . . . . . . . . . . . . . . . . . . . . . 178<br> 3.4 Fatigue Life for Randomly Varying Loads . . . . . . . . . . . . . . . . 181<br>3.5 Criteria of Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183<br> References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187<br> <br>Theory of Mechanisms<br>Dan B. Marghitu<br>1. Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190<br> 1.1 Motions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190<br> 1.2 Mobility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190<br>1.3 Kinematic Pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191<br> 1.4 Number of Degrees of Freedom . . . . . . . . . . . . . . . . . . . . . . 199<br> 1.5 Planar Mechanisms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200<br><br>2. Position Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202<br> 2.1 Cartesian Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202<br> 2.2 Vector Loop Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208<br><br>3. Velocity and Acceleration Analysis . . . . . . . . . . . . . . . . . . . . . . . . . 211<br> 3.1 Driver Link . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212<br> 3.2 RRR Dyad. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212<br>3.3 RRT Dyad. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214<br> 3.4 RTR Dyad. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215<br> 3.5 TRT Dyad. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216<br><br>4. Kinetostatics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223<br> 4.1 Moment of a Force about a Point . . . . . . . . . . . . . . . . . . . . . 223<br> 4.2 Inertia Force and Inertia Moment . . . . . . . . . . . . . . . . . . . . . 224<br>4.3 Free-Body Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227<br> 4.4 Reaction Forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228<br> 4.5 Contour Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229<br>References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241<br> <br>CHAPTER 5 Machine Components<br> Dan B. Marghitu, Cristian I. Diaconescu, and Nicolae Craciunoiu<br>1. Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244<br>1.1 Screw Thread . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244<br> 1.2 Power Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247<br><br>2. Gears . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253<br>2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253<br> 2.2 Geometry and Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . 253<br>2.3 Interference and Contact Ratio . . . . . . . . . . . . . . . . . . . . . . . 258<br>2.4 Ordinary Gear Trains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261<br> 2.5 Epicyclic Gear Trains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262<br>2.6 Differential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267<br>2.7 Gear Force Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270<br> 2.8 Strength of Gear Teeth . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275<br><br>3. Springs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283<br>3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283<br> 3.2 Material for Springs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283<br>3.3 Helical Extension Springs . . . . . . . . . . . . . . . . . . . . . . . . . . 284<br>3.4 Helical Compression Springs . . . . . . . . . . . . . . . . . . . . . . . . 284<br> 3.5 Torsion Springs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290<br>3.6 Torsion Bar Springs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292<br>3.7 Multileaf Springs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293<br> 3.8 Belleville Springs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296<br><br></div><div style="text-align:left">4. Rolling Bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297<br> 4.1 Generalities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297<br>4.2 Classi®cation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298<br>4.3 Geometry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298<br> 4.4 Static Loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303<br>4.5 Standard Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304<br>4.6 Bearing Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308<br> <br>5. Lubrication and Sliding Bearings. . . . . . . . . . . . . . . . . . . . . . . . . . 318<br>5.1 Viscosity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318<br>5.2 Petroff's Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323<br> 5.3 Hydrodynamic Lubrication Theory . . . . . . . . . . . . . . . . . . . . 326<br>5.4 Design Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328<br>References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336<br> <br>CHAPTER 6 Theory of Vibration<br>Dan B. Marghitu, P. K. Raju, and Dumitru Mazilu<br><br>1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340<br><br>2. Linear Systems with One Degree of Freedom . . . . . . . . . . . . . . . . . 341<br> 2.1 Equation of Motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342<br>2.2 Free Undamped Vibrations . . . . . . . . . . . . . . . . . . . . . . . . . 343<br>2.3 Free Damped Vibrations . . . . . . . . . . . . . . . . . . . . . . . . . . . 345<br> 2.4 Forced Undamped Vibrations . . . . . . . . . . . . . . . . . . . . . . . 352<br>2.5 Forced Damped Vibrations . . . . . . . . . . . . . . . . . . . . . . . . . 359<br>2.6 Mechanical Impedance. . . . . . . . . . . . . . . . . . . . . . . . . . . . 369<br> 2.7 Vibration Isolation: Transmissibility. . . . . . . . . . . . . . . . . . . . 370<br>2.8 Energetic Aspect of Vibration with One DOF . . . . . . . . . . . . . 374<br>2.9 Critical Speed of Rotating Shafts. . . . . . . . . . . . . . . . . . . . . . 380<br> <br>3. Linear Systems with Finite Numbers of Degrees of Freedom . . . . . . . 385<br>3.1 Mechanical Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386<br>3.2 Mathematical Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392<br> 3.3 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404<br>3.4 Analysis of System Model . . . . . . . . . . . . . . . . . . . . . . . . . . 405<br>3.5 Approximative Methods for Natural Frequencies. . . . . . . . . . . 407<br> <br>4. Machine-Tool Vibrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416<br>4.1 The Machine Tool as a System . . . . . . . . . . . . . . . . . . . . . . 416<br>4.2 Actuator Subsystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 418<br> 4.3 The Elastic Subsystem of a Machine Tool . . . . . . . . . . . . . . . 419<br>4.4 Elastic System of Machine-Tool Structure . . . . . . . . . . . . . . . . 435<br>4.5 Subsystem of the Friction Process. . . . . . . . . . . . . . . . . . . . . 437<br> 4.6 Subsystem of Cutting Process . . . . . . . . . . . . . . . . . . . . . . . 440<br>References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 444<br><br>CHAPTER 7 Principles of Heat Transfer<br> Alexandru Morega<br>1. Heat Transfer Thermodynamics . . . . . . . . . . . . . . . . . . . . . . . . . . 446<br>1.1 Physical Mechanisms of Heat Transfer: Conduction, Convection,<br>and Radiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451<br> <br></div><div style="text-align:left">4. Rolling Bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297<br>4.1 Generalities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297<br> 4.2 Classi®cation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298<br>4.3 Geometry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298<br>4.4 Static Loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303<br> 4.5 Standard Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304<br>4.6 Bearing Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308<br><br>5. Lubrication and Sliding Bearings. . . . . . . . . . . . . . . . . . . . . . . . . . 318<br> 5.1 Viscosity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318<br>5.2 Petroff's Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323<br>5.3 Hydrodynamic Lubrication Theory . . . . . . . . . . . . . . . . . . . . 326<br> 5.4 Design Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328<br>References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336<br><br>CHAPTER 6 Theory of Vibration<br> Dan B. Marghitu, P. K. Raju, and Dumitru Mazilu<br>1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340<br>2. Linear Systems with One Degree of Freedom . . . . . . . . . . . . . . . . . 341<br> 2.1 Equation of Motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342<br>2.2 Free Undamped Vibrations . . . . . . . . . . . . . . . . . . . . . . . . . 343<br>2.3 Free Damped Vibrations . . . . . . . . . . . . . . . . . . . . . . . . . . . 345<br> 2.4 Forced Undamped Vibrations . . . . . . . . . . . . . . . . . . . . . . . 352<br>2.5 Forced Damped Vibrations . . . . . . . . . . . . . . . . . . . . . . . . . 359<br>2.6 Mechanical Impedance. . . . . . . . . . . . . . . . . . . . . . . . . . . . 369<br> 2.7 Vibration Isolation: Transmissibility. . . . . . . . . . . . . . . . . . . . 370<br>2.8 Energetic Aspect of Vibration with One DOF . . . . . . . . . . . . . 374<br>2.9 Critical Speed of Rotating Shafts. . . . . . . . . . . . . . . . . . . . . . 380<br> 3. Linear Systems with Finite Numbers of Degrees of Freedom . . . . . . . 385<br>3.1 Mechanical Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386<br>3.2 Mathematical Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392<br> 3.3 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404<br>3.4 Analysis of System Model . . . . . . . . . . . . . . . . . . . . . . . . . . 405<br>3.5 Approximative Methods for Natural Frequencies. . . . . . . . . . . 407<br> 4. Machine-Tool Vibrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416<br>4.1 The Machine Tool as a System . . . . . . . . . . . . . . . . . . . . . . 416<br>4.2 Actuator Subsystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 418<br> 4.3 The Elastic Subsystem of a Machine Tool . . . . . . . . . . . . . . . 419<br>4.4 Elastic System of Machine-Tool Structure . . . . . . . . . . . . . . . . 435<br>4.5 Subsystem of the Friction Process. . . . . . . . . . . . . . . . . . . . . 437<br> 4.6 Subsystem of Cutting Process . . . . . . . . . . . . . . . . . . . . . . . 440<br>References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 444<br><br>CHAPTER 7 Principles of Heat Transfer<br> Alexandru Morega<br>1. Heat Transfer Thermodynamics . . . . . . . . . . . . . . . . . . . . . . . . . . 446<br>1.1 Physical Mechanisms of Heat Transfer: Conduction, Convection,<br>and Radiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451<br> Table of Contents ix<br>1.2 Technical Problems of Heat Transfer . . . . . . . . . . . . . . . . . . . 455<br>2. Conduction Heat Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456<br>2.1 The Heat Diffusion Equation . . . . . . . . . . . . . . . . . . . . . . . . 457<br> 2.2 Thermal Conductivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459<br>2.3 Initial, Boundary, and Interface Conditions . . . . . . . . . . . . . . . 461<br>2.4 Thermal Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463<br> 2.5 Steady Conduction Heat Transfer . . . . . . . . . . . . . . . . . . . . . 464<br>2.6 Heat Transfer from Extended Surfaces (Fins) . . . . . . . . . . . . . 468<br>2.7 Unsteady Conduction Heat Transfer . . . . . . . . . . . . . . . . . . . 472<br> 3. Convection Heat Transfer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488<br>3.1 External Forced Convection . . . . . . . . . . . . . . . . . . . . . . . . . 488<br>3.2 Internal Forced Convection . . . . . . . . . . . . . . . . . . . . . . . . . 520<br> 3.3 External Natural Convection. . . . . . . . . . . . . . . . . . . . . . . . . 535<br>3.4 Internal Natural Convection . . . . . . . . . . . . . . . . . . . . . . . . . 549<br>References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 555<br> <br>CHAPTER 8 Fluid Dynamics<br>Nicolae Craciunoiu and Bogdan O. Ciocirlan<br>1. Fluids Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 560<br>1.1 De®nitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 560<br> 1.2 Systems of Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 560<br>1.3 Speci®c Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 560<br>1.4 Viscosity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 561<br> 1.5 Vapor Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 562<br>1.6 Surface Tension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 562<br>1.7 Capillarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 562<br> 1.8 Bulk Modulus of Elasticity . . . . . . . . . . . . . . . . . . . . . . . . . . 562<br>1.9 Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 563<br>1.10 Hydrostatic Forces on Surfaces . . . . . . . . . . . . . . . . . . . . . . . 564<br> 1.11 Buoyancy and Flotation . . . . . . . . . . . . . . . . . . . . . . . . . . . 565<br>1.12 Dimensional Analysis and Hydraulic Similitude . . . . . . . . . . . . 565<br>1.13 Fundamentals of Fluid Flow. . . . . . . . . . . . . . . . . . . . . . . . . 568<br> 2. Hydraulics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 572<br>2.1 Absolute and Gage Pressure . . . . . . . . . . . . . . . . . . . . . . . . 572<br>2.2 Bernoulli's Theorem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573<br> 2.3 Hydraulic Cylinders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 575<br>2.4 Pressure Intensi®ers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 578<br>2.5 Pressure Gages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 579<br> 2.6 Pressure Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 580<br>2.7 Flow-Limiting Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . 592<br>2.8 Hydraulic Pumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 595<br> 2.9 Hydraulic Motors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 598<br>2.10 Accumulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 601<br>2.11 Accumulator Sizing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 603<br> 2.12 Fluid Power Transmitted . . . . . . . . . . . . . . . . . . . . . . . . . . . 604<br>2.13 Piston Acceleration and Deceleration. . . . . . . . . . . . . . . . . . . 604<br>2.14 Standard Hydraulic Symbols . . . . . . . . . . . . . . . . . . . . . . . . 605<br> 2.15 Filters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 606<br></div><div style="text-align:left">2.16 Representative Hydraulic System . . . . . . . . . . . . . . . . . . . . . 607<br> References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 610<br> <br>CHAPTER 9 Control<br>Mircea Ivanescu<br>1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 612<br> 1.1 A Classic Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 613<br> 2. Signals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 614<br>3. Transfer Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 616<br> 3.1 Transfer Functions for Standard Elements . . . . . . . . . . . . . . . 616<br> 3.2 Transfer Functions for Classic Systems . . . . . . . . . . . . . . . . . 617<br>4. Connection of Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 618<br> 5. Poles and Zeros. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 620<br> 6. Steady-State Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 623<br>6.1 Input Variation Steady-State Error . . . . . . . . . . . . . . . . . . . . . 623<br> 6.2 Disturbance Signal Steady-State Error . . . . . . . . . . . . . . . . . . 624<br> 7. Time-Domain Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 628<br>8. Frequency-Domain Performances . . . . . . . . . . . . . . . . . . . . . . . . . 631<br> 8.1 The Polar Plot Representation . . . . . . . . . . . . . . . . . . . . . . . 632<br> 8.2 The Logarithmic Plot Representation. . . . . . . . . . . . . . . . . . . 633<br>8.3 Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 637<br> 9. Stability of Linear Feedback Systems . . . . . . . . . . . . . . . . . . . . . . . 639<br> 9.1 The Routh±Hurwitz Criterion . . . . . . . . . . . . . . . . . . . . . . . . 640<br>9.2 The Nyquist Criterion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 641<br> 9.3 Stability by Bode Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . 648<br> 10. Design of Closed-Loop Control Systems by Pole-Zero Methods . . . . . 649<br>10.1 Standard Controllers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 650<br> 10.2 P-Controller Performance . . . . . . . . . . . . . . . . . . . . . . . . . . 651<br> 10.3 Effects of the Supplementary Zero . . . . . . . . . . . . . . . . . . . . 656<br>10.4 Effects of the Supplementary Pole . . . . . . . . . . . . . . . . . . . . 660<br> 10.5 Effects of Supplementary Poles and Zeros . . . . . . . . . . . . . . . 661<br> 10.6 Design Example: Closed-Loop Control of a Robotic Arm . . . . . 664<br>11. Design of Closed-Loop Control Systems by Frequential Methods . . . . 669<br> 12. State Variable Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 672<br> 13. Nonlinear Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 678<br>13.1 Nonlinear Models: Examples . . . . . . . . . . . . . . . . . . . . . . . . 678<br> 13.2 Phase Plane Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 681<br> 13.3 Stability of Nonlinear Systems . . . . . . . . . . . . . . . . . . . . . . . 685<br>13.4 Liapunov's First Method . . . . . . . . . . . . . . . . . . . . . . . . . . . 688<br> 13.5 Liapunov's Second Method . . . . . . . . . . . . . . . . . . . . . . . . . 689<br> 14. Nonlinear Controllers by Feedback Linearization . . . . . . . . . . . . . . . 691<br>15. Sliding Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 695<br> 15.1 Fundamentals of Sliding Control . . . . . . . . . . . . . . . . . . . . . 695<br> 15.2 Variable Structure Systems . . . . . . . . . . . . . . . . . . . . . . . . . 700<br>A. Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 703<br> A.1 Differential Equations of Mechanical Systems . . . . . . . . . . . . . 703<br> A.2 The Laplace Transform . . . . . . . . . . . . . . . . . . . . . . . . . . . . 707<br>A.3 Mapping Contours in the s-Plane . . . . . . . . . . . . . . . . . . . . . 707<br> A.4 The Signal Flow Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 712<br> References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 714<br><br>APPENDIX Differential Equations and Systems of Differential Equations<br> <br>Horatiu Barbulescu<br>1. Differential Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 716<br> 1.1 Ordinary Differential Equations: Introduction . . . . . . . . . . . . . 716<br>1.2 Integrable Types of Equations . . . . . . . . . . . . . . . . . . . . . . . 726<br> 1.3 On the Existence, Uniqueness, Continuous Dependence on a<br> Parameter, and Differentiability of Solutions of Differential<br>Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 766<br> 1.4 Linear Differential Equations . . . . . . . . . . . . . . . . . . . . . . . . 774<br> 2. Systems of Differential Equations . . . . . . . . . . . . . . . . . . . . . . . . . . 816<br>2.1 Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 816<br> 2.2 Integrating a System of Differential Equations by the<br> Method of Elimination . . . . . . . . . . . . . . . . . . . . . . . . . . . . 819<br>2.3 Finding Integrable Combinations . . . . . . . . . . . . . . . . . . . . . 823<br> 2.4 Systems of Linear Differential Equations. . . . . . . . . . . . . . . . . 825<br> 2.5 Systems of Linear Differential Equations with Constant<br>Coef®cients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 835<br> References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 845<br> Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 847<br><br></div><div style="color:rgb(255,0,0);text-align:center"> <b>Read More !<br></b></div><div style="text-align:center"> <b style="color:rgb(255,0,0)">Free Download it !</b><br></div></div><div><div dir="ltr"><div style="text-align:center"><a href="http://goo.gl/J1wMR" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/b_dl.gif"></a><a href="http://marinenotesonline.blogspot.in/p/buy-marine-notes.html" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/b_buy.gif"></a><font style="text-align:center" color="#ff0000"><a href="http://marinenotesonline.blogspot.com/p/marine-notes-online-order-form-var.html" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/WriteDocument_zps380e535b.png"></a><a href="mailto:marinenotesonline@gmail.com" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/1310735291_icon-email_zps9ea76f56.jpg"></a><br> Free Download <b><span style="color:rgb(0,0,255)">&</span></b> Buy Online via Secure Paypal </font><font style="text-align:center" color="#0000ff">or</font><font style="text-align:center" color="#ff0000"> Fill Order Form for Alternative.</font></div> <div style="text-align:center"><b style="color:rgb(0,0,255)"><font size="1"><a href="http://marinenotesonline.blogspot.in/" target="_blank">Marine Notes Online</a></font></b><br></div></div></div> </div> <br><br>--<br> Posted By Blogger to <a href="http://marinenotesonline.blogspot.com/2013/01/mechanical-engineers-handbook-by-dan-b.html" target="_blank">Marine Notes Online</a> on 1/27/2013 02:55:00 am</div> </div> <div class="blogger-post-footer"><script type="text/javascript"><!--
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</center></div>Marine Noteshttp://www.blogger.com/profile/14270820931606062583noreply@blogger.com0tag:blogger.com,1999:blog-838411897140673717.post-2732785277087989332013-01-27T02:04:00.001+05:302013-01-27T02:04:18.906+05:30Welding Theory and Application<div dir="ltr"><i style="color:rgb(0,0,255);font-family:georgia,serif;text-align:center"><font size="4"><b>WELDING THEORY & APPLICATION</b></font></i><br><div class="gmail_quote"><div dir="ltr"><div style="text-align:center"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrvwY4InN4ChjJA-1GF3ybDEMVpwQyKN1xVwFgSF9o7ZYpr7VtzSmgAk9iZ_q3b9b5pEbd77s0ptqenYmlfuMOuktO8_Zf73E5y6dCkrpldLlf6q11bGK1pWA3Y4602cYpSFc9z3xFlsA2/s1600/Welding+Theory+and+Application-706577.jpg" target="_blank"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrvwY4InN4ChjJA-1GF3ybDEMVpwQyKN1xVwFgSF9o7ZYpr7VtzSmgAk9iZ_q3b9b5pEbd77s0ptqenYmlfuMOuktO8_Zf73E5y6dCkrpldLlf6q11bGK1pWA3Y4602cYpSFc9z3xFlsA2/s320/Welding+Theory+and+Application-706577.jpg" border="0" alt=""></a><br> <b><span style="color:rgb(255,0,0)">TOC of WELDING THEORY & APPLICATION</span></b><br><br><div style="text-align:left"><b>Table of Contents</b><br></div><br><div style="text-align:left">CHAPTER 1 - INTRODUCTION<br>Section I - General<br> Section II - Theory<br><br>CHAPTER 2 - SAFETY PRECAUTIONS IN WELDING OPERATIONS<br>Section I - General Safety Precautions<br>Section II - Safety Precautions in Oxyfuel Welding<br>Section III - Safety in Arc Welding and Cutting<br> Section IV - Safety Precautions for Gas Shielded Arc Welding<br>Section V - Safety Precautions for Welding and Cutting Containers That Have Held<br>Combustibles<br>Section VI - Safety Precautions for Welding and Cutting Polyurethane Foam Filled<br> Assemblies<br><br>CHAPTER 3 - PRINT READING AND WELDING SYMBOLS<br>Section I - Print Reading<br>Section II - Weld and Welding Symbols<br><br>CHAPTER 4 - JOINT DESIGN AND PREPARATION OF METALS<br><br>CHAPTER 5 - WELDING AND CUTTING EQUIPMENT<br> Section I - Oxyacetylene Welding Equipment<br>Section II - Oxyacetylene Cutting Equipment<br>Section III - Arc Welding Equipment and Accessories<br>Section IV - Resistance Welding Equipment<br>Section V - Thermit Welding Equipment<br> Section VI - Forge Welding Tools and Equipment<br><br>CHAPTER 6 - WELDING TECHNIQUES<br>Section I - Description<br>Section II - Nomenclature of the Weld<br>Section III - Types of Welds and Welded Joints<br>Section IV - Welding Positions<br> Section V - Expansion and Contraction in Welding Operations<br>Section VI - Welding Problems and Solutions<br><br>CHAPTER 7 - METALS IDENTIFICATION<br>Section I - Characteristics<br>Section II - Standard Metal Designations<br> Section III - General Description and Weldability of Ferrous Metals<br>Section IV - General Description and Weldability of Nonferrous Metals<br><br>CHAPTER 8 - ELECTRODES AND FILLER METALS<br>Section I - Types of Electrodes<br> Section II - Other Filler Metals<br><br>CHAPTER 9 - MAINTENANCE WELDING OPERATIONS FOR MILITARY EQUIPMENT<br><br>CHAPTER 10 - ARC WELDING AND CUTTING PROCESSES<br>Section I - General<br>Section II - Arc Processes<br>Section III - Related Processes<br> <br>CHAPTER 11 - OXYGEN FUEL GAS WELDING PROCEDURES<br>Section I - Welding Processes and Techniques<br>Section II - Welding and Brazing Ferrous Metals<br>Section III - Related Processes<br>Section IV - Welding, Brazing, and Soldering Nonferrous Metals<br> <br>CHAPTER 12 - SPECIAL APPLICATIONS<br>Section I - Underwater Cutting and Welding with the Electric Arc<br>Section II - Underwater Cutting with Oxyfuel<br>Section III - Metallizing<br>Section IV - Flame Cutting Steel and Cast Iron<br> </div></div><div style="text-align:left">Section V - Flame Treating Metal<br>Section VI - Cutting and Hard Surfacing with the Electric Arc<br>Section VII - Armor Plate Welding and Cutting<br>Section VIII - Pipe Welding<br> Section IX - Welding Cast Iron, Cast Steel, Carbon Steel, and Forgings<br>Section X - Forge Welding<br>Section XI - Heat Treatment of Steel<br>Section XII - Other Welding Processes<br><br>CHAPTER 13 - DESTRUCTIVE AND NONDESTRUCTIVE TESTING<br> Section I - Performance Testing<br>Section II - Visual Inspection and Corrections<br>Section III - Physical Testing<br>APPENDIX A - REFERENCES<br>APPENDIX B - PROCEDURE GUIDES FOR WELDING<br>APPENDIX C - TROUBLESHOOTING PROCEDURES<br> APPENDIX D - MATERIALS USED FOR BRAZING, WELDING, SOLDERING, CUTTING, AND METALLIZING<br>APPENDIX E - MISCELLANEOUS DATA<br><br>GLOSSARY<br><br>LIST OF ILLUSTRATIONS<br><br>LIST OF TABLES<br><br>WARNINGS<br><br></div><div style="text-align:left"> <i><b style="color:rgb(0,0,255)">Download it for Free !</b></i><br></div><div style="text-align:center"><br clear="all"></div><div><div dir="ltr"><div style="text-align:center"><a href="http://goo.gl/vcwSx" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/b_dl.gif"></a><a href="http://marinenotesonline.blogspot.in/p/buy-marine-notes.html" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/b_buy.gif"></a><font style="text-align:center" color="#ff0000"><a href="http://marinenotesonline.blogspot.com/p/marine-notes-online-order-form-var.html" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/WriteDocument_zps380e535b.png"></a><a href="mailto:marinenotesonline@gmail.com" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/1310735291_icon-email_zps9ea76f56.jpg"></a><br> Free Download <b><span style="color:rgb(0,0,255)">&</span></b> Buy Online via Secure Paypal </font><font style="text-align:center" color="#0000ff">or</font><font style="text-align:center" color="#ff0000"> Fill Order Form for Alternative.</font></div> <div style="text-align:center"><b style="color:rgb(0,0,255)"><font size="1"><a href="http://marinenotesonline.blogspot.in/" target="_blank">Marine Notes Online</a></font></b><br></div></div></div> </div> <br><br>--<br> Posted By Blogger to <a href="http://marinenotesonline.blogspot.com/2013/01/welding-theory-and-application.html" target="_blank">Marine Notes Online</a> on 1/27/2013 01:10:00 am</div> </div> <div class="blogger-post-footer"><script type="text/javascript"><!--
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</center></div>Marine Noteshttp://www.blogger.com/profile/14270820931606062583noreply@blogger.com0tag:blogger.com,1999:blog-838411897140673717.post-63196477021754887292013-01-26T17:17:00.001+05:302013-01-26T17:17:48.882+05:30General theory about Welding<div dir="ltr"><div>GENERAL</div><div>Welding is any metal joining process wherein coalescence is produced by heating the metal to suitable</div><div>temperatures, with or without the application of pressure and with or without the use of filler metals.</div> <div>Basic welding processes are described and illustrated in this manual. Brazing and soldering, procedures</div><div>similar to welding, are also covered.</div><div><br></div><div>METALS</div><div>a. Metals are divided into two classes, ferrous and nonferrous. Ferrous metals are those in the iron class</div> <div>and are magnetic in nature. These metals consist of iron, steel, and alloys related to them. Nonferrous</div><div>metals are those that contain either no ferrous metals or very small amounts. These are generally divided</div> <div>into the aluminum, copper, magnesium, lead, and similar groups.</div><div>b. Information contained in this circular covers theory and application of welding for all types of metals</div><div>including recently developed alloys.</div> <div><br></div><div><b>SAFETY PRECAUTIONS IN WELDING OPERATIONS</b><br></div><div>GENERAL SAFETY PRECAUTIONS<br></div><div><div>GENERAL</div><div>a. To prevent injury to personnel, extreme caution should be exercised when using any types of welding</div> <div>equipment. Injury can result from fire, explosions, electric shock, or harmful agents. Both the general</div><div>and specific safety precautions listed below must be strictly observed by workers who weld or cut</div> <div>metals.</div><div>b. Do not permit unauthorized persons to use welding or cutting equipment.</div><div>c. Do not weld in a building with wooden floors, unless the floors are protected from hot metal by means</div><div> of fire resistant fabric, sand, or other fireproof material. Be sure that hot sparks or hot metal will not fall</div><div>on the operator or on any welding equipment components.</div><div>d. Remove all flammable material, such as cotton, oil, gasoline, etc., from the vicinity of welding.</div> <div>e. Before welding or cutting, warm those in close proximity who are not protected to wear proper</div><div>clothing or goggles.</div><div>f. Remove any assembled parts from the component being welded that may become warped or otherwise</div> <div>damaged by the welding process.</div><div>g. Do not leave hot rejected electrode stubs, steel scrap, or tools on the floor or around the welding</div><div>equipment. Accidents and/or fires may occur.</div><div>h. Keep a suitable fire extinguisher nearby at all times. Ensure the fire extinguisher is in operable</div> <div>condition.</div><div>i. Mark all hot metal after welding operations are completed. Soapstone is commonly used for this</div><div>purpose.</div></div><div><br></div><div>PERSONAL PROTECTIVE EQUIPMENT<br></div><div><div> a. General. The electric arc is a very powerful source of light, including visible, ultraviolet, and infrared.</div><div>Protective clothing and equipment must be worn during all welding operations. During all oxyacetylene</div> <div>welding and cutting proccesses, operators must use safety goggles to protect the eyes from heat, glare,</div><div>and flying fragments of hot metals. During all electric welding processes, operators must use safety</div> <div>goggles and a hand shield or helmet equipped with a suitable filter glass to protect against the intense</div><div>ultraviolet and infrared rays. When others are in the vicinity of the electric welding processes, the area</div> <div>must be screened so the arc cannot be seen either directly or by reflection from glass or metal.</div><div><br></div><div>b. Helmets and Shields.</div><div><br></div><div>(1) Welding arcs are intensely brilliant lights. They contain a proportion of ultraviolet light which</div> <div>may cause eye damage. For this reason, the arc should never be viewed with the naked eye within</div><div>a distance of 50.0 ft (15.2 m). The brilliance and exact spectrum, and therefore the danger of the</div><div>light, depends on the welding process, the metals in the arc, the arc atmosphere, the length of the</div> <div>arc, and the welding current. Operators, fitters, and those working nearby need protection against</div><div>arc radiation. The intensity of the light from the arc increases with increasing current and arc</div><div> voltage. Arc radiation, like all light radiation, decreases with the square of the distance. Those</div><div>processes that produce smoke surrounding the arc have a less bright arc since the smoke acts as a</div><div>filter. The spectrum of the welding arc is similar to that of the sun. Exposure of the skin and eyes</div> <div>to the arc is the same as exposure to the sun.</div><div><br></div><div>(2) Being closest, the welder needs a helmet to protect his eyes and face from harmful light and</div><div>particles of hot metal. The welding helmet is generally constructed of a pressed fiber</div> <div>insulating material. It has an adjustable headband that makes it usable by persons with different</div><div>head sizes. To minimize reflection and glare produced by the intense light, the helmet is dull</div><div>black in color. It fits over the head and can be swung upward when not welding. The chief</div> <div>advantage of the helmet is that it leaves both hands free, making it possible to hold the work and</div><div>weld at the same time.</div></div><div><br></div><div><div>(3) The hand-held shield provides the same protection as the helmet, but is held in</div> <div>position by the handle. This type of shield is frequently used by an observer or a person who</div><div>welds for a short period of time.</div><div><br></div><div>(4) The protective welding helmet has lens holders used to insert the cover glass and the filter</div> <div>glass or plate. Standard size for the filter plate is 2 x 4-1/4 in. (50 x 108 mm). In some helmets</div><div>lens holders open or flip upwards. Lenses are designed to prevent flash burns and eye damage by</div><div>absorption of the infrared and ultraviolet rays produced by the arc. The filter glasses or plates</div> <div>come in various optical densities to filter out various light intensities, depending on the welding</div><div>process, type of base metal, and the welding current. The color of the lens, usually green, blue, or</div> <div>brown, is an added protection against the intensity of white light or glare. Colored lenses make it</div><div>possible to clearly see the metal and weld. Table 2-1 lists the proper filter shades to be used. A</div><div> magnifier lens placed behind the filter glass is sometimes used to provide clear vision.</div></div><div><br></div><div><div>FIRE HAZARDS</div><div><br></div><div>a. Fire prevention and protection is the responsibility of welders, cutters, and supervisors.</div> <div>Approximately six percent of the fires in industrial plants are caused by cutting and welding which has</div><div>been done primarily with portable equipment or in areas not specifically designated for such work. The</div> <div>elaboration of basic precautions to be taken for fire prevention during welding or cutting is found in the</div><div>Standard for Fire Prevention in Use of Cutting and Welding Processes, National Fire Protection</div> <div>Association Standard 51B, 1962. Some of the basic precautions for fire prevention in welding or cutting</div><div>work are given below.</div><div><br></div><div>b. During the welding and cutting operations, sparks and molten spatter are formal which sometimes fly</div> <div>considerable distances. Sparks have also fallen through cracks, pipe holes, or other small openings in</div><div>floors and partitions, starting fires in other areas which temporarily may go unnoticed. For these reasons,</div> <div>welding or cutting should not be done near flammable materials unless every precaution is taken to</div><div>prevent ignition.</div><div><br></div><div>c. Hot pieces of base metal may come in contact with combustible materials and start fires. Fires and</div> <div>explosions have also been caused when heat is transmitted through walls of containers to flammable</div><div>atmospheres or to combustibles within containers. Anything that is combustible or flammable is</div><div>susceptible to ignition by cutting and welding.</div> <div><br></div><div>d. When welding or cutting parts of vehicles, the oil pan, gasoline tank, and other parts of the vehicle are</div><div>considered fire hazards and must be removed or effectively shielded from sparks, slag, and molten</div> <div>metal.</div><div>e. Whenever possible, flammable materials attached to or near equipment requiring welding, brazing, or</div><div>cutting will be removed. If removal is not practical, a suitable shield of heat resistant material should be</div> <div>used to protect the flammable material. Fire extinguishing equipment, for any type of fire that may be</div><div>encountered, must be present.</div></div><div><br></div><div><div>HEALTH PROTECTION AND VENTILATION</div> <div><br></div><div>a. General.</div><div>(1) All welding and thermal cutting operations carried on in confined spaces must be adequately</div><div>ventilated to prevent the accumulation of toxic materials, combustible gases, or possible oxygen</div> <div>deficiency. Monitoring instruments should be used to detect harmful atmospheres. Where it is</div><div>impossible to provide adequate ventilation, air-supplied respirators or hose masks approved for</div><div>this purpose must be used. In these situations, lookouts must be used on the outside of the</div> <div>confined space to ensure the safety of those working within. Requirements in this section have</div><div>been established for arc and gas welding and cutting. These requirements will govern the amount</div><div>of contamination to which welders may be exposed:</div> <div>(a) Dimensions of the area in which the welding process takes place (with special regard to height of ceiling).</div><div>(b) Number of welders in the room.</div><div>(c) Possible development of hazardous fumes, gases, or dust according to the metals involved.</div> <div>(d) Location of welder's breathing zone with respect to rising plume of fumes.</div><div><br></div><div>(2) In specific cases, there are other factors involved in which respirator protective devices</div><div>(ventilation) should be provided to meet the equivalent requirements of this section. They</div> <div>include:</div><div>(a) Atomspheric conditions.</div><div>(b) Generated heat.</div><div>(c) Presence of volatile solvents.</div></div><div><br></div><div><div>(3) In all cases, the required health protection, ventilation standards, and standard operating</div> <div>procedures for new as well as old welding operations should be coordinated and cleaned through</div><div>the safety inspector and the industrial hygienist having responsibility for the safety and health</div><div>aspects of the work area.</div> </div><div><br></div><div><div>b. Screened Areas. When welding must be performed in a space entirely screened on all sides, the</div><div>screens shall be arranged so that no serious restriction of ventilation exists. It is desirable to have the</div> <div>screens mounted so that they are about 2.0 ft (0.6 m) above the floor, unless the work is performed at</div><div>such a low level that the screen must be extended closer to the floor to protect workers from the glare of</div> <div>welding.</div></div><div><br></div><div><div>c. Concentration of Toxic Substances. Local exhaust or general ventilating systems shall be provided</div><div>and arranged to keep the amount of toxic frees, gas, or dusts below the acceptable concentrations as set</div> <div>by the American National Standard Institute Standard 7.37; the latest Threshold Limit Values (TLV) of</div><div>the American Conference of Governmental Industrial Hygienists; or the exposure limits as established</div> <div>by Public Law 91-596, Occupational Safety and Health Act of 1970. Compliance shall be determined by</div><div>sampling of the atmsphere. Samples collected shall reflect the exposure of the persons involved. When a</div> <div>helmet is worn, the samples shall be collected under the helmet.</div></div><div><br></div><div><div>NOTE</div><div>Where welding operations are incidental to general operations, it is considered good</div><div>practice to apply local exhaust ventilation to prevent contamination of the general work</div> <div>area.</div><div><br></div><div>d. Respiratory Protective Equipment. Individual respiratory protective equipment will be well retained.</div><div>Only respiratory protective equipment approved by the US Bureau of Mines, National Institute of</div> <div>Occupational Safety and Health, or other government-approved testing agency shall be utilized.</div><div>Guidance for selection, care, and maintenance of respiratory protective equipment is given in Practices</div><div> for Respiratory Protection, American National Standard Institute Standard 788.2 and TB MED 223.</div><div>Respiratory protective equipment will not be transferred from one individual to another without being</div><div>disinfected.</div> <div><br></div><div>e. Precautionary Labels. A number of potentially hazardous materials are used in flux coatings,</div><div>coverings, and filler metals. These materials, when used in welding and cutting operations, will become</div> <div>hazardous to the welder as they are released into the atmosphere. These include, but are not limited to,</div><div>the following materials: fluorine compounds, zinc, lead, beryllium, cadmium, and mercury. See</div><div> paragraph 2-4 i through 2-4 n. The suppliers of welding materials shall determine the hazard, if any,</div><div>associated with the use of their materials in welding, cutting, etc.</div><div><br></div><div>(1) All filler metals and fusible granular materials shall carry the following notice, as a minimum,</div> </div><div><div>on tags, boxes, or other containers:</div><div>CAUTION</div><div>Welding may produce fumes and gases hazardous to health. Avoid breathing these fumes</div><div>and gases. Use adequate ventilation. See American National Standards Institute Standard</div> <div>Z49.1-1973, Safety in Welding and Cutting published by the American Welding Society.</div><div><br></div><div>(2) Brazing (welding) filler metals containing cadmium in significant amounts shall carry the</div><div>following notice on tags, boxes, or other containers:</div> <div>WARNING</div><div>CONTAINS CADMIUM - POISONOUS FUMES MAY BE FORMED ON HEATING</div><div>Do not breathe fumes. Use only with adequate ventilation, such as fume collectors,</div><div>exhaust ventilators, or air-supplied respirators. See American National Standards Institute</div> <div>Standard Z49.1-1973. If chest pain, cough, or fever develops after use, call physician</div><div>immediately.</div><div><br></div><div>(3) Brazing and gas welding fluxes containing fluorine compounds shall have a cautionary</div> <div>wording. One such wording recommended by the American Welding Society for brazing and gas</div><div>welding fluxes reads as follows:</div><div>CAUTION</div><div>CONTAINS FLUORIDES</div><div>This flux, when heated, gives off fumes that may irritate eyes, nose, and throat.</div> <div>Avoid fumes--use only in well-ventilated spaces.</div><div>Avoid contact of flux with eyes or skin.</div><div>Do not take internally.</div><div><br></div><div>f. Ventilation for General Welding and Cutting.</div><div> (1) General. Mechanical ventilation shall be provided when welding or cutting is done on metals</div><div>not covered in subparagraphs i through p of this section, and under the following conditions:</div><div>(a) In a space of less than 10,000 cu ft (284 cu m) per welder.</div> <div>(b) In a roan having a ceiling height of less than 16 ft (5 m).</div><div>(c) In confined spaces or where the welding space contains partitions, balconies, or other</div></div><div><br></div>-- <br><div style="text-align:center"> <a href="http://marinenotes.blogspot.in" target="_blank">marinenotes.blogspot.in</a><br><a href="http://marinenotes.blogspot.in/" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/ship/marinenotes/marinenotes.png"></a><br> </div> </div> <div class="blogger-post-footer"><script type="text/javascript"><!--
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</center></div>Marine Noteshttp://www.blogger.com/profile/14270820931606062583noreply@blogger.com1tag:blogger.com,1999:blog-838411897140673717.post-52565118082234147762013-01-25T23:11:00.001+05:302013-01-25T23:11:05.900+05:30Function of an air ejectors.<div dir="ltr"><div style="text-align:center"><div style="text-align:left"><h3 class="" style="margin:0px;font-family:Arial,Tahoma,Helvetica,FreeSans,sans-serif">FUNCTION</h3><div><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiLTTeh2jDQtQlTct1xyJXoQBZkFQrmwo6vT4S-bxayjoEiZadAkts9lncFZCIbSN_6spjFDwLndNJI7LE-G6flM9aYvkJ659lhiMRk12Tw7_HLNsD_ivYgKLnNr954DiI94JiG3jQAfA/s1600/hphtr1-765901.gif"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiLTTeh2jDQtQlTct1xyJXoQBZkFQrmwo6vT4S-bxayjoEiZadAkts9lncFZCIbSN_6spjFDwLndNJI7LE-G6flM9aYvkJ659lhiMRk12Tw7_HLNsD_ivYgKLnNr954DiI94JiG3jQAfA/s320/hphtr1-765901.gif" border="0" alt="" id="BLOGGER_PHOTO_ID_5837443239639850210" /></a><br> </div><span style="font-size:13px;font-family:Arial,Tahoma,Helvetica,FreeSans,sans-serif;line-height:18px">Air ejector units are generally of the steam jet type. Although electrically powered units offer the advantage of ease of installation and slightly improved operating efficiency their maintenance requirements has ensured that the most common type on larger installations are steam powered Their primary function is to remove non- condensible gases from the condenser</span><br style="font-size:13px;font-family:Arial,Tahoma,Helvetica,FreeSans,sans-serif;line-height:18px"> <span style="font-size:13px;font-family:Arial,Tahoma,Helvetica,FreeSans,sans-serif;line-height:18px">After passing through the nozzle the high velocity stream jet entrains air and vapour , compresses it, and the mixture passes to a condenser section were it is cooled. The air with any uncondensed steam and vapour passing to the second stage were further compression of the air takes place.</span><br style="font-size:13px;font-family:Arial,Tahoma,Helvetica,FreeSans,sans-serif;line-height:18px"> <span style="font-size:13px;font-family:Arial,Tahoma,Helvetica,FreeSans,sans-serif;line-height:18px">Depending upon the number of stages of the air ejector, the air is now discharged to atmosphere or to a final stage and then to atmosphere.</span><br style="font-size:13px;font-family:Arial,Tahoma,Helvetica,FreeSans,sans-serif;line-height:18px"> <span style="font-size:13px;font-family:Arial,Tahoma,Helvetica,FreeSans,sans-serif;line-height:18px">The condensers are of the surface type and are cooled by condensate, in this way acting as a feed heater.</span><br style="font-size:13px;font-family:Arial,Tahoma,Helvetica,FreeSans,sans-serif;line-height:18px"> <span style="font-size:13px;font-family:Arial,Tahoma,Helvetica,FreeSans,sans-serif;line-height:18px">Either, two complete units or two ejectors mounted on one condenser are used , nozzle diameters are very small typically 1.2 to 4.7 mm and are liable to wear, abrasion and blockage.</span><br style="font-size:13px;font-family:Arial,Tahoma,Helvetica,FreeSans,sans-serif;line-height:18px"> <span style="font-size:13px;font-family:Arial,Tahoma,Helvetica,FreeSans,sans-serif;line-height:18px">When manouevring or at rest provision must be made to ensure that there is adequate flow of condensate through the condenser to provide cooling . This is achieved by means of a recirculating v/v which leads condensate from the outlet of the air ejector condenser outlet ( and other low pressure feed heaters such as an evapourator ) back to the main condenser. The opening of this v/v should be limited as it leads to a loss of plant efficiency. </span><br> </div><div style="text-align:left"><span style="font-size:13px;font-family:Arial,Tahoma,Helvetica,FreeSans,sans-serif;line-height:18px"><br></span></div><div style="text-align:left"><h3 class="" style="margin:0px;font-family:Arial,Tahoma,Helvetica,FreeSans,sans-serif"> Electric Powered</h3><div><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh3Pnj0FJzit5RtKqt3O8N63XRziIHThpPloi1f8oaEmK8WnW-BbgFwJntdhYtJvgZcyXJL5oay6fxFqwIDPdiOHOZIGcgjoBQwYYgyXMqeuD8xGRpZwaNLnE8CgF73V8f_uTfqTU4NbQ/s1600/ejec1-768504.gif"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh3Pnj0FJzit5RtKqt3O8N63XRziIHThpPloi1f8oaEmK8WnW-BbgFwJntdhYtJvgZcyXJL5oay6fxFqwIDPdiOHOZIGcgjoBQwYYgyXMqeuD8xGRpZwaNLnE8CgF73V8f_uTfqTU4NbQ/s320/ejec1-768504.gif" border="0" alt="" id="BLOGGER_PHOTO_ID_5837443248029758594" /></a><br></div><div><span style="font-family:Arial,Tahoma,Helvetica,FreeSans,sans-serif;font-size:13px;line-height:18px">The position of the cooler can vary; either as shown, incorporated into the tank or on the suction side of the pump.</span><br> </div></div><br></div> </div> <div class="blogger-post-footer"><script type="text/javascript"><!--
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The basic components of this system are an evaporator, a compressor device, a condenser and a refrigerant control device. This system employs a steam injector or booster (instead of mechanical compressor) to compress the refrigerant to the required condenser pressure level. In this system, water is used as the refrigerant. Since the freezing point of water is 0°C, therefore, it cannot be used for applications below 0°C. The steam jet refrigeration system is widely used in food processing plants for pre-cooling of vegetables and concentrating fruit juices, gas plants, paper mills, breweries etc.</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><b></b></p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> <span id="more-699"></span></p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><b>Principle of steam jet refrigeration system: -</b></p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">The boiling point of a liquid changes with change in external pressure. In normal conditions, pressure exerted on the surface of a liquid is the atmospheric pressure. If this atmospheric pressure is reduced on the surface of a liquid, by some means, then the liquid will start boiling at lower temperature, because of reduced pressure. This basic principal of boiling of liquid at lower temperature by reducing the pressure on its surface is used in steam jet refrigeration system.</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">The boiling point of pure water at standard atmospheric pressure of 760 mm of Hg is 1 00°C. It may be noted that water boils at 12′C if the pressure on the surface of water is kept at 0.014 bar and at 7′C if the pressure on the surface of water is 0.01 bar. The reduced pressure on the surface of water is maintained by throttling the steam through the jets or nozzles.</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><b>Working of steam jet refrigeration system: -</b></p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">The flash chamber or evaporator is a large vessel and is heavily insulated to avoid the rise in temperature of water due to high ambient temp. It is fitted with perforated pipes for spraying water. The warm water coming out of the refrigerated space is sprayed into the flash water chamber where some of which is converted into vapours after absorbing the latent heat, thereby cooling the rest of water.</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">The high pressure steam from the boiler is passed through the steam nozzle thereby increase its velocity. The high velocity steam in the ejector would entrain the water vapours from the flash chamber which would result in further information of vapour. The mixture of steam and water vapour passes through the ventilate-tube of the ejector and gets compressed. The temperature and pressure rises considerably and fed to the water cooled condenser where it gets condensed. The condensate is <span style="font-size:12px;line-height:17px">again fed to the boiler as feed water. A constant water level is maintained in the flash chamber and any loss of water due to evaporation is made up from the make- up water line.</span></p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><b>Steam Ejector: -</b></p><div style="float:center;padding:0px;"><!-- BEGIN SMOWTION TAG - 728x90 - DO NOT MODIFY -->
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<!-- END SMOWTION TAG - 728x90 - DO NOT MODIFY --></div><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> The steam ejector is one of the important components of a steam jet refrigeration system. It is used to compress the water vapours coming out of the flash chamber. It uses the energy of fast moving jet of steam to entrain the vapours from the flash chamber and then compress it. The high pressure steam from the boiler expands while flowing through the convergent divergent nozzle. The expansion causes a very low pressure and increases steam velocity. The steam attains very high velocities in the range of 1000 m/s to 1350 m/s. The nozzles are designed for lowest operating pressure ratio between nozzle throat and exit. The nozzle pressure ratio of less than 200 is undesirable because of poor ejector efficiency when operating at low steam pressure.</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">The water vapour from the flash chamber are entrained by the high velocity steam and both are mixed in the mixing section at constant pressure. The mean velocity of the mixture will be supersonic, after the mixing is complete. This supersonic steam gets a normal shock, in the constant area throat of the diffuser. This results in the rise of pressure and subsonic flow. The function of the diverging portion of the diffuser is to recover the velocity head as pressure head by gradually reducing the velocity.</p> <div style="float:center;padding:0px;"><!-- BEGIN SMOWTION TAG - 468x60 - DO NOT MODIFY -->
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<!-- END SMOWTION TAG - 468x60 - DO NOT MODIFY --></div> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><b>Analysis of Steam Jet Refrigeration System</b><b>: -</b></p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">The temperature – entropy (T– s) and enthalpy-entropy (h – s) diagrams for a steam jet refrigeration system are shown in fig. (a) and (b) respectively.</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">The point A represents the initial condition of the motive steam before passing through the nozzle and the point B is the final condition of the steam, assuming isentropic expansion. The point C represents the initial condition of the water vapour in the flash chamber or evaporator and the point E is the condition of the mixture of high velocity steam from the nozzle and the entrained water vapour before compression. Assuming isentropic compression, the final condition of the mixture discharged to the condenser is represented by point F. The final condition of the before mixing with the water vapour is shown at point D. The make-up water is supplied at point G whose temperature is slightly lower than the condenser temperature and is throttled to point H in the flash chamber.</p> <div><br></div>-- <br><div style="text-align:center"><a href="http://marinenotes.blogspot.in" target="_blank">marinenotes.blogspot.in</a><br><a href="http://marinenotes.blogspot.in/" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/ship/marinenotes/marinenotes.png"></a><br> </div> </div> <div class="blogger-post-footer"><script type="text/javascript"><!--
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Power source gives rotary motion to crank. With the help of connecting rod we translate reciprocating motion to piston in the cylinder.</p> <p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px">c) Suction pipe: – one end of suction pipe remains dip in the liquid and other end attached to the inlet of the cylinder.</p><p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px"> d) Delivery pipe: – one end of delivery pipe attached with delivery part and other end at discharge point.</p><p></p><div><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> e) Suction and Delivery value: – suction and delivery values are provided at the suction end and delivery end respectively. These values are non-return values.</p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> <u><strong>WORKING OF RECIPROCATING PUMP</strong></u></p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> <u></u></p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">Operation of reciprocating motion is done by the power source (i.e. electric motor or i.c engine, etc). Power source gives rotary motion to crank; with the help of connecting rod we translate reciprocating motion to piston in the cylinder (i.e. intermediate link between connecting rod and piston). When crank moves from inner dead centre to outer dead centre vacuum will create in the cylinder. When piston moves outer dead centre to inner dead centre and piston force the water at outlet or delivery value.</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><u><strong>EXPRESSION FOR DISCHARGE OF THE PUMP:-</strong></u></p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><a href="http://engineering.myindialist.com/wp-content/uploads/2009/10/clip_image0047.gif" style="color:rgb(41,112,166);text-decoration:initial"><img title="clip_image004" height="30" alt="clip_image004" src="http://engineering.myindialist.com/wp-content/uploads/2009/10/clip_image004_thumb7.gif" width="52" border="0" style="border: 0px; max-width: 600px; display: inline;"></a></p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">Where: –</p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> Q: – discharge in m<sup>3</sup>/sec</p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">A: – cross-section of piston or cylinder in m<sup>2</sup></p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">L: – length of stroke in meter</p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> N: – speed of crank in r.p.m</p></div>-- <br><div style="text-align:center"><a href="http://marinenotes.blogspot.in" target="_blank">marinenotes.blogspot.in</a><br><a href="http://marinenotes.blogspot.in/" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/ship/marinenotes/marinenotes.png"></a><br> </div> </div> <div class="blogger-post-footer"><script type="text/javascript"><!--
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This type of pumps uses the centrifugal force created by an impeller which spins at high speed inside the pump casing.</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><u></u></p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> <span id="more-528"></span></p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><strong><u>Principle</u>:</strong> Its principle work on Centrifugal force.<u></u></p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><u></u></p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> <u></u></p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><u></u></p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> <u></u></p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><u></u></p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> <u></u></p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><u></u></p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> <u><strong>Diagram</strong></u></p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><u><strong><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhWB0xyyotj7E1J2X16DxyQTD7oy9ocIJBDhe9pd0hHYYSWmO0bSuDQYNORo6-aVHWmIJCjdJNoMeviUETRaeHzW3RRqOYlQlKibM97hr8lwvoriy6DsUJsCwhfkLnqO3ycYMFG368F2A/s1600/clip_image00238-731847.jpg"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhWB0xyyotj7E1J2X16DxyQTD7oy9ocIJBDhe9pd0hHYYSWmO0bSuDQYNORo6-aVHWmIJCjdJNoMeviUETRaeHzW3RRqOYlQlKibM97hr8lwvoriy6DsUJsCwhfkLnqO3ycYMFG368F2A/s320/clip_image00238-731847.jpg" border="0" alt="" id="BLOGGER_PHOTO_ID_5837075441748903986" /></a><br> </strong></u></p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"></p><p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px"> <strong><u>CONTRUCTION DETAILS OF A CENTRIFUGAL PUMP</u>:</strong> Centrifugal pump is classified as the following:-</p><p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px">1. Stationary components</p> <p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px">2. Rotating components</p><p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px">1. Stationary components of the centrifugal pump are the following:</p> <p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px">a) Casing: – It is an air tight passage surrounding the impeller. It is designed in such a way that the kinetic energy of the water discharged at the outlet of the impeller is converted into pressure energy before the water leaves the casing and enters the delivery pipe. Types of casing:-</p> <p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px">· Volute casing: – It is spiral type of casing in which area of flow increase gradually. The increase in area of flow decreases the velocity of flow and increases the pressure of water.</p> <p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px">· Vortex casing: – if a circular chamber is introduced between casing and the impeller, the casing is known as vortex casing.</p><p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px"> · Casing with guide blades: – the impeller is surrounded by a series of guide blades mounted on a ring know as diffuser.</p><p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px">b) Suction pipe: – a pipe whose one ends is connected to the inlet of the pump and other end dip into water in a sump.</p> <p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px">c) Delivery pipe: – a pipe whose one end is connected to the outlet of the pump and other end is involved in delivering the water at a required height.</p> <p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px">2. Rotating component of the centrifugal pump is Impeller.</p><p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px">Impeller: – It is the main rotating part that provides the centrifugal acceleration to the fluid. Classification of impeller:</p> <p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px">a) Based on direction of flow:</p><p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px">· Axial-flow: – the fluid maintains significant axial-flow direction components from the inlet to outlet of the rotor.</p> <p style="margin:0px 0px 10px;padding:0px;font-size:12px;line-height:17px">· Radial-flow: – the flow across the blades involves a substantial radial-flow component at the rotor inlet, outlet and both.</p><p></p><div><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> Mixed-flow: – there may be significant axial and radial flow velocity components for the flow through the rotor row.</p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> b) Based on suction type:</p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">· Single suction: – liquid inlet on one side.</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">· Double suction: – liquid inlet to the impeller symmetrically from both sides.</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">c) Based on mechanical construction:</p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> · Closed: – shrouds or sidewall is enclosing the vanes.</p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> · Open: – no shrouds or wall to enclose the vanes.</p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> · Semi-open or vortex type.</p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><strong><u>Working</u>:</strong> Water is drawn into the pump from the source of supply through a short length of pipe (suction pipe). Impeller rotates; it spins the liquid sitting in the cavities between the vanes outwards and provides centrifugal acceleration with the kinetic energy.</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">This kinetic energy of a liquid coming out an impeller is harnessed by creating a resistance to flow. The first resistance is created by the pump volute (casing) that catches the liquid and shows it down.</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">In the discharge nozzle, the liquid further decelerates and its velocity is converted to pressure according to BERNOULLI'S PRINCIPAL.</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><strong><u>SPECIFIC SPEED</u>:</strong> – speed of an imaginary pump geometrically similar in every respect to the actual pump and capable of delivering unit quantity against a unit head. It is denoted by N<sub>S</sub>:-</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">N<sub>S </sub>= N (Q)<sup>1/2</sup>/(H)<sup>3/4</sup></p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">Where: –</p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> N: – pump speed in r.p.m</p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">Q: – discharge in m<sup>3</sup>/sec</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">H: – head per stage in mete</p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> Tabulated form of specific speed in a centrifugal pump:<br></p><table cellspacing="0" cellpadding="0" border="1" style="border:2px solid rgb(204,204,204);border-collapse:collapse;margin:5px 0px 10px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> <tbody><tr><td valign="top" width="139" style="border:1px solid rgb(204,204,204);padding:3px 10px;vertical-align:top"><p style="margin:0px 0px 10px;padding:0px">Pump</p></td><td valign="top" width="108" style="border:1px solid rgb(204,204,204);padding:3px 10px;vertical-align:top"> <p style="margin:0px 0px 10px;padding:0px">Speed</p></td><td valign="top" width="180" style="border:1px solid rgb(204,204,204);padding:3px 10px;vertical-align:top"><p style="margin:0px 0px 10px;padding:0px">Specific speed (in r.p.m)</p> </td></tr><tr><td valign="top" width="139" style="border:1px solid rgb(204,204,204);padding:3px 10px;vertical-align:top"><p style="margin:0px 0px 10px;padding:0px">Radial flow</p></td><td valign="top" width="108" style="border:1px solid rgb(204,204,204);padding:3px 10px;vertical-align:top"> <p style="margin:0px 0px 10px;padding:0px">Slow</p><p style="margin:0px 0px 10px;padding:0px">Medium</p><p style="margin:0px 0px 10px;padding:0px">High</p></td><td valign="top" width="180" style="border:1px solid rgb(204,204,204);padding:3px 10px;vertical-align:top"> <p style="margin:0px 0px 10px;padding:0px">10-30</p><p style="margin:0px 0px 10px;padding:0px">30-35</p><p style="margin:0px 0px 10px;padding:0px">50-80</p></td></tr><tr><td valign="top" width="139" style="border:1px solid rgb(204,204,204);padding:3px 10px;vertical-align:top"> <p style="margin:0px 0px 10px;padding:0px">Mixed flow</p></td><td valign="top" width="108" style="border:1px solid rgb(204,204,204);padding:3px 10px;vertical-align:top"> </td><td valign="top" width="180" style="border:1px solid rgb(204,204,204);padding:3px 10px;vertical-align:top"> <p style="margin:0px 0px 10px;padding:0px">80-160</p></td></tr><tr><td valign="top" width="139" style="border:1px solid rgb(204,204,204);padding:3px 10px;vertical-align:top"><p style="margin:0px 0px 10px;padding:0px">Axial flow</p> </td><td valign="top" width="108" style="border:1px solid rgb(204,204,204);padding:3px 10px;vertical-align:top"> </td><td valign="top" width="180" style="border:1px solid rgb(204,204,204);padding:3px 10px;vertical-align:top"> <p style="margin:0px 0px 10px;padding:0px">100-450</p></td></tr></tbody></table><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"> <u></u></p><p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px"><u><strong>EFFICIENCIES OF CENTRIFUGAL PUMPS:-</strong></u></p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">Mechanical efficiencies: – It is ratio of the impeller power to the shaft power.</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">Hydraulic efficiencies: – It is ratio of the manometric head to the Euler head.</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">Volumetric efficiencies:- It is ratio of the actual to the theoretical discharge.</p> <p style="margin:0px 0px 10px;padding:0px;color:rgb(85,85,85);font-family:Verdana,'BitStream vera Sans',Tahoma,Helvetica,sans-serif;font-size:12px;line-height:17px">Overall efficiencies: – It is ratio of the water power to the shaft power.</p> </div>-- <br><div style="text-align:center"><a href="http://marinenotes.blogspot.in" target="_blank">marinenotes.blogspot.in</a><br><a href="http://marinenotes.blogspot.in/" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/ship/marinenotes/marinenotes.png"></a><br> </div> </div> <div class="blogger-post-footer"><script type="text/javascript"><!--
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<strong>Resistance Spot Welding:</strong></div>
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In spot welding the weld is effected by the heat produced due to resistance to the flow of current through two or more overlapping work pieces held pressed together between the electrodes. This is the simplest form of resistance welding and does not pose any problem for welding sheets ranging u to 12.5 mm in thickness. The majority of spot welding is however done with metal pieces less than 6 mm thick.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiOSD4yqV5-rFbeFnBKbP0YZKO_1nww2eZnE7Yrb7WUNrCQDzXOB5baRr5ge3na3-PO1Ibzl1bXS67PLVf3ZA2rHjO4bHwkbnGv7TFkFkLIJajq6BOaQSl9jw_aSp_8xqAbA0KIgLexjA/s1600/01-resistance-spot-welding-spot-welding-machine-762430.jpg"><img alt="" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiOSD4yqV5-rFbeFnBKbP0YZKO_1nww2eZnE7Yrb7WUNrCQDzXOB5baRr5ge3na3-PO1Ibzl1bXS67PLVf3ZA2rHjO4bHwkbnGv7TFkFkLIJajq6BOaQSl9jw_aSp_8xqAbA0KIgLexjA/s320/01-resistance-spot-welding-spot-welding-machine-762430.jpg" id="BLOGGER_PHOTO_ID_5834282555405790466" /></a></div>
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For best results the surfaces to be welded must be free from scales and foreign matter. Spot welds should not be made too close to the end of a workpiece or to each other. When a spot weld is attempted too close to the edge of the work pieces molten metal may flow out of the weld zone. Similarly if two spot welds are made too close to each other electric current may be shunted through a parallel path provided by an adjacent weld.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh40uxCQNRi1bVlMAugWrNuA1uajCIPFycQGBQyeFG4MsVhF67QF7gDNpOXw8PVnSXgA5gn-cbDo3QsIwijURrWbFMboSIHWCZBbO2Cd7GtqdgktVF3Du3s39IsdLXOoR0eeXK3hmFbgg/s1600/01-resistance-welding-machine-what-is-resistive-welding1-764707.jpg"><img alt="" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh40uxCQNRi1bVlMAugWrNuA1uajCIPFycQGBQyeFG4MsVhF67QF7gDNpOXw8PVnSXgA5gn-cbDo3QsIwijURrWbFMboSIHWCZBbO2Cd7GtqdgktVF3Du3s39IsdLXOoR0eeXK3hmFbgg/s320/01-resistance-welding-machine-what-is-resistive-welding1-764707.jpg" id="BLOGGER_PHOTO_ID_5834282561439283394" /></a></div>
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<span style="font-size: 13px;">The resulting weld nugget is typically 5 to 10 mm in diameter, with a heat affected zone extending slightly beyond the nugget into the base metal.</span></div>
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<span style="font-size: 13px;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhtsPeQJklUopbGAzzIlILCVce9ENqBB6yJOFj_9fqSRXVxZAqPGAbXSvZ19a2dM92n3RQJlp_b4PC_Dv7PW9Ug2RuNED4WzOvBteVgbJotYieoEKEcPQ8RV9a7TQx9dmSgJplYtULEHw/s1600/01-resistance-spot-welding-process-spot-welding-parameters-766537.jpg"><img alt="" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhtsPeQJklUopbGAzzIlILCVce9ENqBB6yJOFj_9fqSRXVxZAqPGAbXSvZ19a2dM92n3RQJlp_b4PC_Dv7PW9Ug2RuNED4WzOvBteVgbJotYieoEKEcPQ8RV9a7TQx9dmSgJplYtULEHw/s320/01-resistance-spot-welding-process-spot-welding-parameters-766537.jpg" id="BLOGGER_PHOTO_ID_5834282570099514146" /></a></span></div>
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Spot welding machines are available in three different varieties:</div>
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<span style="background-color: #cccccc;">1. Stationary single spot welding machines</span></div>
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<span style="background-color: #cccccc;"> a. Rocker arm type</span></div>
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<span style="background-color: #cccccc;"> b. Direct pressure type</span></div>
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<span style="background-color: #cccccc;">2. Portable single spot welding machines</span></div>
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<span style="background-color: #cccccc;">3. Multiple spot welding machines</span></div>
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<span style="background-color: #cccccc;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEggrxadylGjOFPPJGpix9i7qhcLjfYz33vHakagJOh8rd6cKyz9gHr5QnEOQIXJcAPzmXKg3UNpq4ksA2hzWotX_7UrlmayY5MPNgeh9fd-rp30s4CA4grRjuSQFWs6SrQCF7130TqseQ/s1600/01-resistance-spot-welding-aluminum-spot-welding-gun-769365.jpg"><img alt="" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEggrxadylGjOFPPJGpix9i7qhcLjfYz33vHakagJOh8rd6cKyz9gHr5QnEOQIXJcAPzmXKg3UNpq4ksA2hzWotX_7UrlmayY5MPNgeh9fd-rp30s4CA4grRjuSQFWs6SrQCF7130TqseQ/s320/01-resistance-spot-welding-aluminum-spot-welding-gun-769365.jpg" id="BLOGGER_PHOTO_ID_5834282586192855826" /></a></span></div>
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<span style="background-color: #cccccc;"></span></div>
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<span style="background-color: #cccccc;"><strong>Rocker arm type:</strong></span></div>
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<span style="background-color: #cccccc;">The rocker arm type is the simplest and cheapest but is limited to smaller sizes. It employs rocking motion of the upper arm for applying pressure and raising and lowering of the upper electrode.</span></div>
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<span style="background-color: #cccccc;"><strong>Direct pressure type:</strong></span></div>
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<span style="background-color: #cccccc;">The direct pressure type employs a straight line motion of the upper electrode along the face of the machine column and can be used for larger sizes.</span></div>
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<span style="background-color: #cccccc;"><strong>Electrode Tip shape:</strong></span></div>
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<span style="background-color: #cccccc;">The size and shape of the weld spot is determined by the electrode tip, the most common electrode shape being:</span></div>
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<span style="background-color: #cccccc;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPB6-8iR2EnEYcviI6v8eUukvZbS0ZKhZ-ar8T3SRTAbU_fttyNoAhhVapM9G7dwcNTQEn7W8KakjhNBspsm1pDWVVEjoMTsw497b9kHZf8oeNrwZCEeuL5U71NS8145Co0FnNo_Pg9A/s1600/01-resistance-spot-welding-electrode-tip-tip-shape-770462.jpg"><img alt="" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPB6-8iR2EnEYcviI6v8eUukvZbS0ZKhZ-ar8T3SRTAbU_fttyNoAhhVapM9G7dwcNTQEn7W8KakjhNBspsm1pDWVVEjoMTsw497b9kHZf8oeNrwZCEeuL5U71NS8145Co0FnNo_Pg9A/s320/01-resistance-spot-welding-electrode-tip-tip-shape-770462.jpg" id="BLOGGER_PHOTO_ID_5834282589861669058" /></a></span></div>
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<span style="background-color: #cccccc;">1. Round (most common)</span></div>
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<span style="background-color: #cccccc;">2. Hexagonal</span></div>
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<span style="background-color: #cccccc;">3. Square and other shapes</span></div>
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<span style="background-color: #cccccc;"><strong>Spot Gun Machines:</strong></span></div>
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<span style="background-color: #cccccc;">When the size of the work pieces to be welded increases, then spot welding machines are used on that occasion. A large number of welding guns are available for the purpose. These portable spot welders are connected to the transformers through a long cable and may be taken to the spot where welding is to be done. The electrodes used should have a contact area which gives the desired current density through the work pieces.</span></div>
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<span style="background-color: #cccccc;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEigZn1CdarkwvVvr4-7ATVPgkNKGTQoUTLZxJgkBma2qN9GW-kfQQr_um0H9rlCPc4IExKHl5XOumXRtlq5NtGeJX8HuerGVNH5kqTyAVkf6pL0wwV3DMizOKQxGK5GOpMkdePxU5jwhg/s1600/01-resistance-spot-gun-machines-spot-welding-transformers-772700.jpg"><img alt="" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEigZn1CdarkwvVvr4-7ATVPgkNKGTQoUTLZxJgkBma2qN9GW-kfQQr_um0H9rlCPc4IExKHl5XOumXRtlq5NtGeJX8HuerGVNH5kqTyAVkf6pL0wwV3DMizOKQxGK5GOpMkdePxU5jwhg/s320/01-resistance-spot-gun-machines-spot-welding-transformers-772700.jpg" id="BLOGGER_PHOTO_ID_5834282597610556226" /></a></span></div>
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<span style="background-color: #cccccc;">Welding pressure in these guns may be applied manually, pneumatically or hydraulically depending up on the size and shape of the gun.</span></div>
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<span style="background-color: #cccccc;"><strong>Advantages of Resistance Spot Welding:</strong></span></div>
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<span style="background-color: #cccccc;">1. Adaptability for automation in high rate production of sheet metal assemblies</span></div>
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<span style="background-color: #cccccc;">2. High speed</span></div>
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<span style="background-color: #cccccc;">3. Economical</span></div>
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<span style="background-color: #cccccc;">4. Dimensional accuracy</span></div>
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<span style="background-color: #cccccc;"><strong>Limitations of Resistance Spot Welding:</strong></span></div>
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<span style="background-color: #cccccc;">1. Difficulty for maintenance or repair</span></div>
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<span style="background-color: #cccccc;">2. Adds weight and material cost to the product, compared with a butt joint</span></div>
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<span style="background-color: #cccccc;">3. Generally have higher cost than most arc welding equipment's</span></div>
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<span style="background-color: #cccccc;">4. Produces unfavourable line power demands</span></div>
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<span style="background-color: #cccccc;">5. Low tensile and fatigue strength</span></div>
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<span style="background-color: #cccccc;">6. The full strength of the sheet cannot prevail across a spot welded joint</span></div>
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<span style="background-color: #cccccc;">7. Eccentric loading condition</span></div>
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<br />
<b>Prevention of Earth Faults</b><br />
<br />
Earth faults can be readily detected, but may be difficult to locate and clear; consequently by the correct<br />
choice of equipment and regular maintenance their occurrence can be minimised. This can be summarised as follows:<br />
<br />
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a) Suitable types of enclosures to prevent ingress of moisture, dirt, oil, etc., and to ensure<br />
protection against mechanical damage.<br />
b) Correct rating to avoid excessive temperature rise.<br />
c) Type of insulation chosen to suit the environment<br />
d) Correct glands and seals are to be used on cable ends.<br />
<br />
<b>Maintenance</b><br />
a) Insulation tests are to be performed on a regular basis and always after overhauls<br />
b) Equipment to be maintained as clean as possible<br />
c) Equipment to be dried out after possible ingress of moisture. Most modern deck machinery<br />
have electric heaters fitted. To facilitate this, bags of silica gel crystals may also be enclosed<br />
to absorb small quantities of moisture.<br />
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</center></div>mmanindarkumarhttp://www.blogger.com/profile/05741314530132604499noreply@blogger.com0tag:blogger.com,1999:blog-838411897140673717.post-34413818938024374812013-01-19T23:35:00.001+05:302013-01-19T23:35:35.699+05:30General duties and responsibilities of seafarers<div dir="ltr"><div><b>General duties and responsibilities of seafarers</b></div><div><br></div><div>1.1. Seafarers should participate in ensuring safe working conditions and should be encouraged to express views on working procedures adopted as they may affect safety and health, without fear of dismissal or other prejudicial measures.</div> <div><br></div><div>1.2. Seafarers should have the right to remove themselves from dangerous situations or operations when they have good reason to believe that there is an imminent and serious danger to their safety and health. In such circumstances, the competent officer should be informed of the danger forthwith and seafarers should be protected</div> <div>from undue consequences, in accordance with national conditions and practice.1</div><div><br></div><div>1.3. Notwithstanding paragraph 1.1., seafarers should only abandon ship on the express order of the master or, in his absence, the competent person next in line of authority.</div> <div><br></div><div>1.4. Seafarers should:</div><div>(a) cooperate as closely as possible with the shipowner in the application of the prescribed safety and health measures;</div><div>(b) take care of their own safety and health and of other persons who may be affected by their acts or omissions at work;</div> <div>(c) use and take care of personal protective equipment and clothing at their disposal and not misuse any means provided for their own protection or the protection of others;</div><div>(d) report forthwith to their immediate supervisor any situation which they believe could pose a hazard and which they cannot properly deal with themselves;</div> <div>(e) comply with the prescribed safety and health measures; and</div><div>(f) participate in safety and health meetings.</div><div><br></div><div>1.5 Except in an emergency, seafarers, unless duly authorized, should not interfere with, remove, or displace any safety device or other equipment and appliances furnished for their protection or the protection of others, or interfere with any method or process adopted with a view to preventing accidents and injury to health.</div> <div><br></div><div>1.6. Seafarers should not operate or interfere with equipment which they have not been duly authorized to operate, maintain or use.</div><div><br></div><div>1.7. A seafarer who gives an order or otherwise instructs another seafarer should be certain that the order or instructions are understood.</div> <div><br></div><div>1.8. If a seafarer does not fully understand an order, instruction or any other communication from another seafarer, clarification should be sought.</div><div><br></div><div>1.9. Seafarers have a duty to be particularly diligent during fire, lifeboat and other drills and emergency training.</div> <div><br></div><div>1.10. The crew should implement the shipowner's safety and health policy and programme as delegated to them by the master in a diligent and professional manner and demonstrate their full support for shipboard safety. They should do everything in their power to maintain their own health and safety as well as the health and safety of other crew members and other persons on board.</div> <div><br></div>-- <br><div style="text-align:center"><a href="http://marinenotes.blogspot.in" target="_blank">marinenotes.blogspot.in</a><br><a href="http://marinenotes.blogspot.in/" target="_blank"><img src="http://i844.photobucket.com/albums/ab3/283928/ship/marinenotes/marinenotes.png"></a><br> </div> </div> <div class="blogger-post-footer"><script type="text/javascript"><!--
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<span helvetica="" style="color: midnightblue; font-family: arial,;"><b>Thermal Properties</b></span></div>
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<span style="font-size: small;"><b><span style="font-family: Arial, Helvetica, sans-serif;">Thermal conductivity</span></b></span></h2>
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<span style="font-size: x-small;">The thermal conductivity is the rate of heat transfer through a material in steady state. It is not easily measured, especially for materials with low conductivity but reliable data is readily available for most common materials.</span></div>
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<h2 style="background-color: white;">
<span style="font-family: Arial, Helvetica, sans-serif; font-size: small;">Thermal diffusivity</span><span style="color: #dd2222;"></span></h2>
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<span style="font-size: x-small;">The thermal diffusivity is a measure of the transient heat flow through a material.</span></div>
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<h2 style="background-color: white;">
<span style="font-family: Arial, Helvetica, sans-serif; font-size: small;">Specific heat</span></h2>
<div style="background-color: white;">
<span style="font-size: x-small;">The specific heat is a measure of the amount of energy required to change the temperature of a given mass of material. Specific heat is measured by calorimetry techniques and is usually reported both as C<sub>V</sub>, the specific heat measured at constant pressure, or C<sub>P</sub>, the specific heat measured at constant pressure.</span></div>
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<h2 style="background-color: white;">
<span style="font-family: Arial, Helvetica, sans-serif; font-size: small;">Melting point</span></h2>
<div style="background-color: white;">
<span style="font-size: x-small;">The melting point is the temperature at which a material goes from the solid to the liquid state at one atmosphere. The melting temperature is not usually a design criteria but it offers important clues to other material properties.</span></div>
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<h2 style="background-color: white;">
<span style="font-family: Arial, Helvetica, sans-serif; font-size: small;">Glass transition temp</span></h2>
<div style="background-color: white;">
<span style="font-size: x-small;">The glass transition temperature, or T<sub>g</sub> is an important property of polymers. The glass transition temperature is a temperature range which marks a change in mechanical behavior. Above the glass transition temperature a polymer will behave like a ductile solid or highly viscous liquid. Below T<sub>g</sub> the material will behave as a brittle solid. Depending on the desired properties materials may be used both above and below their glass transition temperature.</span></div>
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<h2 style="background-color: white;">
<span style="font-family: Arial, Helvetica, sans-serif; font-size: small;">Thermal expansion coefficient</span></h2>
<div style="background-color: white;">
<span style="font-size: x-small;">The thermal expansion coefficient is the amount a material will change in dimension with a change in temperature. It is the amount of strain due to thermal expansion per degree Kelvin expressed in units of K<sup>-1</sup>. For isotropic materials " is the same in all directions, anisotropic materials have separate "s reported for each direction which is different.</span></div>
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<h2 style="background-color: white;">
<span style="font-family: Arial, Helvetica, sans-serif; font-size: small;">Thermal shock resistance</span></h2>
<div style="background-color: white;">
<span style="font-size: x-small;">Thermal shock resistance is a measure of how large a change in temperature a material can withstand without damage. Thermal shock resistance is very important to most high temperature designs. Measurements of thermal shock resistance are highly subjective because if is extremely process dependent. Thermal shock resistance is a complicated function of heat transfer, geometry and material properties. The temperature range and the shape of the part play a key role in the material's ability to withstand thermal shock. Tests must be carefully designed to mimic anticipated service conditions to accurately asses the thermal shock resistance of a material.</span></div>
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<h2 style="background-color: white;">
<span style="font-family: Arial, Helvetica, sans-serif; font-size: small;">Creep resistance</span></h2>
<div style="background-color: white;">
<span style="font-size: x-small;">Creep is slow, temperature aided, time dependent deformation. Creep is typically a factor in materials above one third of their absolute melting temperature or two thirds of their glass transition temperature. Creep resistance is an important material property in high temperature design, but it is difficult to quantify with a single value. Creep response is a function of many material and external variables, including stress and temperature. Often other environmental factors such as oxidation or corrosion play a role in the fracture process.</span></div>
<div style="background-color: white;">
<span style="font-size: x-small;">Creep is plotted as strain vs. time. A typical creep curve shows three basic regimes. During stage I, the primary or transient stage, the curve begins at the initial strain, with a relatively high slope or strain rate which decreased throughout stage I until a steady state is reached. Stage II, the steady state stage, is generally the longest stage and represents most of the response. The strain rate again begins to increase in stage III and rupture at t<sub>R</sub>generally follows quickly.</span></div>
<div style="background-color: white;">
<span style="font-size: x-small;">Different applications call for different creep responses. In situations where long life is desired minimum creep rate is the most important material consideration. Testing through stage II should be sufficient for determining minimum creep rate. Is not necessary to proceed all the way to rupture. For this type of test the longer the test the more accurate the creep rate will be. Unfortunately practicality limits most creep tests to times shorter than would be desirable for high accuracy.</span></div>
<div style="background-color: white;">
<span style="font-size: x-small;">For short lived applications such as rocket nozzles the time to failure may be the only consideration. The main issue is whether or not the component fails, not the amount of deformation it may undergo. For this application creep tests may be run to completion but without recording any data but the time to rupture. In this case temperatures may be elevated above expected conditions to provide a margin of safety.</span></div>
<div style="background-color: white;">
<span style="font-size: x-small;">The main objective of a creep test is to study the effects of temperature and stress on the minimum creep rate and the time to rupture. Creep testing is usually run by placing a sample under a constant load at a fixed temperature. The data provided from a complete creep test at a specific temperature, T, and stress includes three creep constants: the dimensionless creep exponent, n, the activation energy Q, and A, a kinetic factor.</span></div>
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