PRV inlet piping sizing criteria

For existing PRV, following guideline can be used to check the adequacy of PRV inlet piping. For non-fiie case, allow 4% Ps, and for fire case, allow 5% Ps for PRV inlet line pressure loss. 

The inlet pressure of relief fluid to PRV inlet piping is the system pressiue at relief condition. This pressure for non-fire case is 110% Ps, and for fire case, it is 121% Ps. 

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