Compressor backflow
Compressor backflow
(OP)
I've observed backflow via antisurge valve on two trains centrifugal compressor. One compressor tripped and gas flow backwards from the other train via failed ESDV and single check valve through antisurge line into the suction scrubber. PSV lifted (sized for fire case), blowdown valve opened but the inlet pressure still exceeded design pressure of the scrubber by about 15% until operator commanded the antisurge valve to close. There was another check valve d/s compressor which hold so the compressor didn't experienced backflow.
The issue was fixed installing double check valve. The question is how sensitive is compresor and gas trubine to spinning in reverse direction? Is it worth to install check valve u/s of recycle line?
The issue was fixed installing double check valve. The question is how sensitive is compresor and gas trubine to spinning in reverse direction? Is it worth to install check valve u/s of recycle line?





RE: Compressor backflow
I had a 4000 HP compressor come apart after running backwards for several hours. The check valve failed (elastomer seat literally gone after 25 years of operation) and the two downstream isolation valves failed to fully shut to the extent that it was able to rotate the compressor with the blow off valve fully open.
The investigation uncovered numerous operation and mainteneance issues to say the least.
RE: Compressor backflow
Anti surge valve should never be used!! I would suggest to revise/conduct HAZOP asessment for this compressor design. If this happened, something wrong with your compressor design. It looks very unsafe.
RE: Compressor backflow
The discharge check valve failed and the 200 psig propane flooded back into the compressor. The gas turbine went from 5200 RPM forward spin to 5200 rpm backwards in under 40 seconds. The gas turbine sucked air through the exhaust and started blowing air through the intake.
the seal pumps ran backwards an blew seal oil out all over the engine.
no fire, but it took several mill to fix.
RE: Compressor backflow