What is a PV breaker? Why is it fitted?

This is a U tube manometer filled with an ethylene glycol solution (as a measure against
freezing). The height of the manometer is manipulated such that the pressure on either side
may displace the solution, into tanks incase of vacuum inside cargo tanks and outside on to the deck incase of over pressurization inside cargo tanks. Usual set values of PV breaker are +1800mmHg on high pressure and -700mmHg on vacuum side.

Pressure-Vacuum breaker is fitted to the IG main line on the deck to protect cargo tanks
from the following:
a. Abnormal rise of pressure in the cargo tanks which occurs when cargo is loaded with
specified rate and that all gas outlets are closed
b. Abnormal drop of pressure in cargo tanks which occurs when cargo is unloaded with
the rated capacity of the cargo pumps and the inert gas blower fails
c. Abnormal rise or drop of pressure in cargo tanks which occurs, when the breather
valves fails to operate properly for the fluctuation of the pressure in cargo tanks, due
to variation in atmospheric and sea water temperatures, altering the vapor pressure
inside tanks

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Main engine interlocks

Interlocks are provided so that the engine can be started or reversed only when certain conditions have been fulfilled. When there is a remote control of engines, it is essential to have interlocks. This reduces the possibility of engine damage and any hazards to the operating personnel. Turning gear Interlock . This device prevents the engine from being started if the Turning gear is engaged. Running Direction Interlock . This prevents the fuel from being supplied if the running direction of the engine does not match the Telegraph. Starting Air Distributor in end position . This prevents starting from taking place if the shifting of the Distributor has not been completed. Main Lube. oil pressure, Piston cooling pressure, Jacket water pressure, and important parameters must be above the required minimum. Auxiliary Blower Interlock . The Auxiliary Blower is provided in case of Constant pressure turbo charging. Air Spring pressure Interlock . In case of the present generation...

Differences between MC/MC-C and ME/ME-C engines

The electrohydraulic control mechanisms of the ME engine replace the following components of the conventional MC engine: Chain drive for camshaft Camshaft with fuel cams, exhaust cams and indicator cams Fuel pump actuating gear, including roller guides and reversing mechanism Conventional fuel pressure booster and VIT system Exhaust valve actuating gear and roller guides Engine driven starting air distributor Electronic governor with actuator Regulating shaft Engine side control console Mechanical cylinder lubricators. The Engine Control System of the ME engine comprises: Control units Hydraulic power supply unit Hydraulic cylinder units, including: Electronically controlled fuel injection, and Electronically controlled exhaust valve activation Electronically controlled starting air valves Electronically controlled auxiliary blowers Integrated electronic governor functions Tacho system Electronically controlled Alpha lubricators

Shell Expansion Plan

It is a two dimensional drawing of a three dimensional surface of the ship’s hull form. This plan is very useful for the following information:It is used for marking the location of a hull Damage on this plan by identifying the strake number , letter and frame number so that the exact location of the damage and also suggested repairs are marked in a localised copy. The shell expansion can be used for finding areas of painting surfaces such as topside, boot topping and bottom areas by applying Simpsons rules directly. In the shell expansion the vertical scale used is different from the horizontal scale and a suitable adjustment has to be made when calculating areas. This becomes useful in solving disputes concerning areas of preparation and painting. It gives information on the thickness of the original strake which is indicated by the number in the circle shown in the strake. The quality of steel used is also shown by letters A,B,D E and AH, BH,DH, EH.

MEOclassIIexamnotes

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