2 Answers

+1 vote
answered Jun 26, 2014 by ekwuemesam (3,660 points) | selected Jun 26, 2014 by Normandy
 
Best answer
Allow ballast piping from one ballast tank to be run through another ballast tank without check valve installed inside the ballast tank or at tank boundary. Same to apply for void compartment bilge piping run through another void tank (Note: both tanks should be from the same piping system). Check valves are not required by Class and API-RP-2T if ballast piping does not run through void compartment or void compartment bilge piping does not run through ballast tank.

This will allow all ballast and bilge valves to be located in central location such as pump room/service space for Operator’s convenience, easy operation, inspection and maintenance and will eliminate valves inside access tunnels.

It is not recommended to install check valves inside tanks/confined space due to accessibility for inspection and replacement and system operation due to valve failure.
+2 votes
answered Jun 26, 2014 by alsieg (2,780 points)
It is acceptable to run ballast pipes or bilge pipes through other ballast tanks without check valve provided there are no valves inside any ballast tank provided it is acceptable for Class.

It is NOT acceptable to run ballast pipes or bilge pipes through void spaces.
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