A relief valve chatters when it is oversized for the actual relieving flow, when inlet piping loses too much pressure on opening, or when built-up backpressure is excessive. The disc lifts, pressure under it collapses, it slams shut, and the cycle repeats many times a second, destroying seats and loosening piping. A common design rule keeps inlet pressure loss under 3 percent of set pressure.
PSV on the separator was chattering so hard the gauge needles were bouncing, it's way oversized for this flow.
Also heard as
- chattering
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.
Pop
For a safety valve to lift suddenly and fully open, discharging with a loud blast at set pressure.
Check valve
A self-acting valve that lets fluid pass in one direction and closes on its own when flow tries to reverse.