The pop is the snap-open action of a safety valve on steam or gas, caused by the huddling chamber suddenly adding lift area once flow starts. People say the valve popped, lifted or blew. A valve that pops often is a symptom: something upstream is overpressuring the system, or operating pressure sits too close to set.
Drum safety popped at 3 a.m., scared the night shift half to death, pull the trend and see what pressure did.
Also heard as
- lift
- blow
- popped
Related terms
Safety valve
A spring-loaded pressure relief valve for steam, gas or vapor that opens with a rapid full lift at set pressure.
Simmer
For a safety valve to leak with an audible hiss or seep just below its set pressure, before it pops.
Chatter
Rapid, violent opening and closing of a relief or check valve that hammers the disc against the seat.
Gag
A clamp or screw fitted to a safety valve to hold its disc shut during a system pressure test.