Wednesday, April 8, 2020

What is the routine maintenance, checks on the PV breaker?

a. Check the seal liquid periodically and replenish the liquid in case 
• Liquid levels of inner and outer pipes do not coincide 
• “0” points of inner and outer pipes do not coincide when the pressure inside 
the cargo tanks is atmospheric pressure 
b. Clean the flame screen in the cover at the top when the ships makes a dock-in 

a. Checking the liquid level of the inner pipe (open the vent cock located at most top of 
the gauge, close the upper gauge cock and open the lower gauge cock) this is also 
termed as “bigger range” 
b. Checking the liquid level of the outer pipe (close the vent cock, open the upper gauge 
cock also open the lower gauge cock) this is also termed as “smaller range” 
Two distinct scales are provided for the liquid gauge one “higher” and other “lower” the 
respective readings (as in ‘a’ and ‘b’) should match numerically 

Disconnect and remove top cover with attached internal stand pipe. Disconnect and remove 
Flame Arrestor Assembly. Remove flame screen. Thoroughly clean internal of flame arrestor. 
Renew flame screen with shipyard supplied equivalent type mesh. Drain breaker liquid, 
thoroughly clean internal breaker body, and stand pipe. Apply two coats of shipyard supplied  tar epoxy by hand brushing to all internal surfaces. Level gauges, cocks and protective  housing to be removed and transported to workshop for cleaning and overhaul. Dismantle  sight glass tubes and cocks for overhauling and cleaning. Upon completion, re-assemble and  re-install onboard with new shipyard supplied approved type jointings, studs, and nuts. 
Prove filling and level cocks clear and free. Disconnect and remove PV Breaker valve. 
Dismantle and clean surfaces. Lap valve and disc. Set valve to +0.21kg/cm2 and 
0.07kg/cm2 in the presence of the attending superintendent. Record and submit calibration 
of valve settings. Close on completion with new shipyard supplied approved type jointings 
and sealing compound and bolts and nuts.

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