What issues do I need to consider in finding a suitable replacement device?
In the referenced valves it is possible that, over time, the elastomeric seats in contact with the spring-loaded poppets can flow into microfine grooves and surface irregularities in the poppets’ metal parts. Inlet-pressure forces that are large compared to normal opening-pressure forces are then required to overcome the resulting breakaway friction. Therefore, for valves used in safety relief applications, improved elastomeric-seat performance is a highly important consideration. A suitable replacement safety relief device must not only offer improved opening characteristics but also provide equal or better relieving capacity than the valve being replaced. Besides acceptable relieving capacity, you should carefully examine other factors that can influence opening ability and other operability concerns.
