When consumption stops, the regulator must close and the downstream pressure must stabilize. This final pressure is called lock-up pressure.
What is lock-up
It is the pressure that forms after the regulator closes, when there is no longer any flow.
What is creep
If the pressure continues to rise slowly after closing, there may be a small internal leak from the regulator seat.
Potential causes
Contaminants, wear on the seat, a problem with the pilot, or poor alignment can cause regulator creep.
Why it is important
Excessive creep can trigger a high pressure switch, monitor regulator, or slam-shut.
Checking
The pressure is recorded immediately after closing consumption and is monitored for a specific period of time.
