So about a year ago the original safety valve failed. It kept popping before full pressure. Tank pressure reads 145-150psi when it blows. Tanks rated and used to fill 170ish before it would cut off.
I've put two different safety check valves rated for 175psi and they both blew around 145-150psi.
I am going grab a new pressure gauge just to double check that the gauge is accurate. But considering the accidental 150psi one I bought first blew at 150psi and so did the ones rated for 175psi tells me the gauge isn't reading wrong.
Any other ideas of why two 175psi safety valves both blew at 150psi instead?
I also replaced the switch just to see and it didn't change anything.
Doesn't make much sense that both pop-offs are 'failing' at the same pressure. Are the pop-offs the same brand? It might be worth picking one up one from another maker. Good call on installing a new gauge as well.
Just because, think I might pull the tank plug and flush all of the piping and the tank just to take tank duff off the table as a cause. I know it's unlikely, but being clean won't hurt anything.
They are progressive. The 175 psi pressure is where it would be fully open, but I could imagine it starting at 150 psi. My Campbell Hausfeld compressor did that from the factory, but not as bad as yours. It was a 150psi compressor, but the switch didn't shut off until about 155, which I assume was an adjustment they botched a little. You could always tell when it was about to shut off because the blowoff valve started to hiss.
In reply to Curtis :
Ah, didn't know that they were progressive. I'm picking up a 200psi so that my tank will actually fill to 175psi before shutting off.
