Pilot operated valve in crude operation

[hageye]

As far as I understand, the pilot will vent a bit of the relieved material to atmosphere each time the pilot-operated PSV opens.
What is your experience in the case of liquid crude?
Do you route the pilot vent to a safe location?

Thank you

 

[JimCasey]

There ARE nonrelieving pilot designs, or you can vent the pilot to the downstream piping.

"Liquid crude" is the part of the question that concerns me. I am reluctant to envision that crude would be compatible with the small crevices and orifices in a pilot valve, especially if it contains entrained sand.

A couple of other things to consider might be (1) a conventional spring-loaded SRV, or (2) a fail-open air-actuated valve driven by a pressure switch on the crude line, connected to a solenoid valve on the air line.