Ashereng is correct. You do not credit the equipment "trip" unless it is as reliable as the PSV itself, i.e. redundant switches or a triconex type safety system.
Will this valve also protect the separator? If so, have you evaluated the fire case?
If blocked outlet is the limiting...
(1) built up backpressure too high. 10% of set pressure for a conventional valve, 30% (i think) for a balanced valve.
(2) Inlet pressure drop too high. 3% of set pressure in hydraulic losses for a conventional or bellows valves. Inlet pressure drop does not affect remote sensed pilot...