With compressor running the relief line blows off
The line coming from the check valve to the pressure switch does not leak air when compressor is off but when the compressor run the line blows off.
Plumbing - Campbell Hausfeld - Single Stage Air Compressor. Single Stage Cast Iron...
Answers & Comments
Check that the non return valve is not stuck closed
hope this helps ian
You must install an unloader valve right at the compressor discharge before the check valve.
Without it, the line is pressurized such that when it
starts, it blows off the line.