Pressure Relief Valve

by Sheldon
(Apex, NC)

Just a cool old engine

Just a cool old engine

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 2hp electric motor for a 5hp Gas Clinton. I have the Clinton starting on the first pull now and need to replace the PRV. The previous owner hastily replaced it and it "pops" at 130 and does not reset until 50. I would like one that resets back at 90 or so. What are my options?


Thanks!

_____________________
Bill says...

That your PRV is "popping" at all tells me that your compressor pressure switch cut out pressure level is too high, or your PRV isn't suited to the compressor.

That you have one that resets is good, most of them on smaller DIY type air compressors simply need to be pushed back to reset them.

I can't tell you if the 130 PSI "pop off" is right for your compressor, though it seems a bit low, since PRV's are a safety device.

If it were me, I'd take the PRV out of the line, and run the compressor, keeping a careful watch on the tank pressure level. Be ready to turn the motor off. Watch the pressure. Maybe the pressure switch is set to shut off at, say, 150 PSI (which is not a too high range normally) and the compressor will shut off then.

That being the case, visit your local compressor repair shop and ask to buy a PRV that opens at about 10 PSI higher than the cut off, and one that needs a manual reset.

Good luck.

Bill

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Why does my pressure release valve open?

by chris daniel
(mooresville, nc)

I do not know how to adjust the pressure release settings so the safety valve does not blow for a Speedaire 5Z185A. Thanks

Chris daniel
cdaniel677@aol.com






Bill answers...

Hey Chris, nice to hear from you.

Listen, if your PRV is going off, that means that the pressure in your tank is above the safety release pressure of your compressor system.

First off, stop using it. Unplug it and drain the air.

Second, that your pressure continues to rise after your compressor has achieved high pressure cut-out in the tank, and the compressor continues to compress air without shutting off, you've got a pressure switch problem.

Install a new one. Check out this page for help in getting parts for your Speedaire.

My ebook, The Home Compressor, covers many aspects of troubleshooting the home compressor, including changing out the pressure switch. It should be (finally :-) ready end of next week. Check it out on this site soon.


Cheers,

Bill

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PRV valve pulsing

The aftercooler prv valve pulses air out while running. I think it may be a stuck valve.






Bill comments...

Howdy, and thanks for writing in.

If the PRV valve is pulsing, it's because it's venting pressure from your system. That is it's job.

What is the pressure in your system when the PRV pulses? I'm going to guess that it's above the normal cut out pressure, and that you may have a pressure switch malfunction.

Pull the ring on the PRV and open it manually, and then shut it again by pushing in. If it's pulsing, then I think it's working fine, and you have a problem elsewhere.

Bill

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