Compressor PRV Valve Opens

It can be a bit startling when a compressor PRV valve opens. The PRV is, of course, the pressure relief valve, and if it opens during compressor operation, that points to a compressor problem developing.

For folks that are not quite sure about what a PRV is and does here's info about compressor PRV's on this site.

It is one thing when your compressor runs, will not stop, and will not build compressed air pressure. It's an entirely different matter when the compressor runs, and runs, does not stop, is building compressed air pressure all the while, and eventually pops the pressure relief valve to vent too-high pressure.

This is a dangerous situation and needs to be remedied immediately.

Compressor PRV Valve Opens - Drawing of PRV valve

If the compressor PRV valve opens at a pressure level below the normal cut out of the compressor, that suggests that it is the PRV valve itself that is the problem. A good cleaning may resolve this, or, it may be necessary to replace it.

Compressor PRV Valve Opens

If the compressor PRV valve opens at a pressure level that is higher than the normal cut out pressure level of the air compressor, that points to the pressure switch being the problem, as the pressure switch is supposed to cut power to the compressor motor when the pressure in the tank reaches the switch cut out set point.

To check it, use a multi-meter to determine if the power is still flowing past the pressure switch when the tank pressure is 5-10 PSI higher than the cut out set point of the switch. Care must be taken when checking as you are dealing with live wires. If power is still flowing through the switch with the pressure higher than the normal cut out, likely the switch has failed.

If you have a PRV problem may I ask that you please see all the questions and answers already posted about this subject below, as I suspect that you will find that someone else has already written in about what you are experiencing.

If your PRV problem is not noted already, there's a form below to ask a question about what to do when your compressor PRV blows. Fill in the form and we'll see if we can help.

And, if you've got a suggestion about solving the "compressor PRV valve blows" problem for someone else, either comment on their post, or start your own thread by using the form.



Ask What to do when your Compressor PRV Valve Blows!

Please read the postings at the bottom of the page to see if it's already covered. If not, tell us about your problem.

Some of the reasons why your compressor PRV valve opens.

Click below to see the problems others have said when their compressor blows its PRV valve open.

PRV not working 
My PRV is popping before getting up to full cut-off pressure. I visited my local repair shop, and the fellow said that I have one of the adjustable types …

The prv valve pops open at 150 psi 
the pressure switch is rate for 140psi on and 175psi off. The PRV valve pops. is their a way to adjust the pressure switch to a lower setting. We have …

S econd stage safety valve blows on high pressure compressor 
Hello Sir, I've faced a problem related to second stage safety valve blows @ 70 BAR pressure. this is high pressure compressor having three stages. …

What size PRV ? 
Hello Thanks for your page. I have a model 47065 Harbor freight air compressor its a 21 gallon 125 psi unit. I needed a direct connection to the tank to …

PRV blows off on second air compressor 
We have a two three phase air compressors connected to two storage tanks at a body paint shop. The problem we are experiencing is that as soon as both …

Air leaking from inter stage PRV valve 
Hi there! I have a Gentilin air compressor C330/20 which is malfunctioning due to air leaking from inter stage safety valve and thereby compressor getting …

Pressure relief valve opens on air compressor 
Hello, my tank which max at 175 psi, will run and shut off normally, except PRV at the start of intercooler pops air every 1/2 second or so until the compressor …

Small PRV on my air compressor is fluttering 
I have a BIG craftsman compressor. The 80 gallon one. Has a 2 cyl, Cast iron V twin style pump. Just a few days ago the little 70 psi prv on the head …

prv valve blows after its full 
I have a speedaire 5f237a. It works fine at first but after about a 1/2 hour of use the prv valve blows. not sure what the problem is. should …

Air valve on compressor is popping off 

12 year old compressor blows off pressure relief valve 
My Sears compressor cutting-off pressure is not working. Also when trying to inflate the tires of my SUV it isn't doing anything even though good air …

Should pressure relief valves close? 
When you trip a prv should it return to its original closed position on its own or do you need to push it back in? __________________ While there are …

I think my compressor pressure relief valve is faulty 
I have a cast iron, single piston, oil filled crank, direct drive, 2 HP Snap On air compressor on a 5 gallon tank. At the outlet of the compressor …

blow off safety valve third stage opens 
Safety valve for third stage is blowing off ________________________ Bill says... Holy cow, Victor, you really don't provide a whole lot of information, …

Why does my compressor pressure relief valve open 
I am glad this site is here! I recently "horse traded" for an older 20 gallon Speedaire compressor. Soemwhere along the way somebody swapped the original …

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