False Load on Centrifugal Compressor

[Chance17]

Can the False Load control valve activate the suction drum safety valve when the compressor is running ?? I have seen numerous analysis saying control valve failure directly activates the suction drum PSV - he required flow being control valve "blow thru" rate. It appears to me to be a double contingency. i.e control valve failure & blocked suction drum outlet. What am I missing ??

FOR EXAMPLE: suction pressure = 40 psig
suction drum safety valve = 75-psig
compressor discharge = 100-psig.
false load control vave = fail open

 

[dcasto]

what if the compressor discharge is connect to a surge drum 10 times bigger than the suction drum. Of course you would have a check valve between the compressor and surge drum?

 

[ChEMatt]

If the recycle valve (I assume this is the "false load" valve, right?) fails it should fail open, and this flow should be accounted for by the suction/inlet drum PSV. It may not be the controlling case, depending on the size of the inlet drum and amount of expected liquid in the drum (fire case) or if the suction control valve fails (if you're controlling suction pressure on a PD compressor).

No, it's not automatic, but it should be taken into consideration.

With a centrifugal I would be more concerned about stonewalling the unit.

Onwards,

Matt