Zoobie,
You didn't give full details on the pilot-op, so beware of these issues:
If the nonrecoverable losses on the inlet side of the pilot-op exceed 3% and you are using a remote sense line location, then capacity should be derated. The simplest way is to reduce the relieving pressure in...
EGT01:
The Consolidated catalog itself answered the basic question: the back pressure limits were quoted for different valve designs. What I found intersting is that the allowed limit was not constant, it varied quite a bit. E.G. the 1511 model valve can see up to 20% of Pset backpressure...
This thread goes into much detail on how to calculate the back pressure on a ASME Section I safety valve: thread408-63173
But the basic question is: what is the allowable back pressure on such a valve?
I have scoured the codes and some vendor catalogs for guidance. The only thing I find is...
