Champion compressor - faulty safety valve?

[ccrunch]

I know that lots of folks on Garage Journal are very knowledgeable about compressors (among other things), so I'm hoping that someone can provide some guidance on a problem I'm having.

I have a 120 gallon Champion duplex compressor that has been pretty much problem free since I purchased it used 3-4 years ago. Just changed the oil and air filter in each pump when I got it, and have been running it since.

Last summer, one of the pressure relief valves on the right-hand pump started popping off repeatedly during a pressurize cycle. I shut the circuit down, manually worked the valve back and forth by hand, flipped the breakers back on and it worked fine until a week or two ago.

Now, as soon as the right hand pump turns on and begins to pressurize the valve pops off every 1-2 seconds. It has done this when the tank is as low as 80psi, so the valve is definitely releasing prematurely (upper tank pressure threshold is 175psi).

In the meanwhile I've just been bringing the tank up to pressure using the left hand pump. Is the valve just shot and needs replacement? Or can this be indicative of a larger issue?

The manual has some troubleshooting recommendations, but I'm not sure if this is a "discharge pressure relief valve" or an "interstage pressure relief valve".



This is the valve in question:



It's on the left side of the right-hand pump, rear air pipe.



I think it's a P09704A:

P09704A

I appreciate anyone's thoughts/input...

 

[ccrunch]

Whoops, posted to wrong section...reposted to General Tool Discussion:

http://www.garagejournal.com/forum/showthread.php?t=277173

Sorry about that, got overzealous...Mods please delete.

 

[mikegt4]

Looks like a standard safety pressure relief valve, available at anyplace that sells air compressors for around $10. Make sure you get the proper pressure rating (embossed on your valve) and thread size.

 

[Bill Bowman]

My Champion does that sometimes. I've adjusted the pressure switch just a tad lower, and it's okay. Seems like 2-3 times per year it acts up.

 

[redmondjp]

My Champion does that sometimes. I've adjusted the pressure switch just a tad lower, and it's okay. Seems like 2-3 times per year it acts up.

It's not a bad idea to manually open these relief valves periodically to ensure that they are not stuck closed. That's why they install the ring on the pintle - so you can pull on it to open the valve.

 

[2gslse]

I can't tell in the pics but when I worked on the compressor at work and it had safety valve issues it was usually related to the intake valves on the 2nd stage not sealing and causing the interstage safety to lift when running. If the first or second stage exhaust valve goes bad then capacity is reduced because the compressed air just travels back into the cyl instead of being compressed ,the intake valve on the 1st stage will usually make a fluttering/honking noise in the air cleaner

 

[redmondjp]

I can't tell in the pics but when I worked on the compressor at work and it had safety valve issues it was usually related to the intake valves on the 2nd stage not sealing and causing the interstage safety to lift when running. If the first or second stage exhaust valve goes bad then capacity is reduced because the compressed air just travels back into the cyl instead of being compressed ,the intake valve on the 1st stage will usually make a fluttering/honking noise in the air cleaner

I've seen that exact same thing happen on a 2-stage compressor where I used to work (interstage relief valve popping open) - it was the inlet valve on the second stage leaking back.

Another thing to check is the accuracy of the pressure gauge (if there is one) - the actual compressor output pressure may be higher than indicated.

 

[ccrunch]

Thanks for the replies, everyone. Per replies in the other thread the valve is on the discharge line, so it's not the interstage valve.

The valve is marked with a 270 PSI pressure rating, 1/4" NPT thread. Confirmed with IAP that P09704A is the correct part #, and ordered it.

Ordered a new pressure gauge (#M519C) as well since the one on the compressor always seemed to read low.

 

[rlitman]

Could it be the check valve at the tank that is sticking, so the line pressure is significantly higher than the tank?

 

[ccrunch]

Could it be the check valve at the tank that is sticking, so the line pressure is significantly higher than the tank?

Interesting thought...I'll look into that if the new valve doesn't fix it.

 

[2gslse]

Instead of buying parts at random you could swap the valve from the other side that is not having issues and if the problem moves then thats the bad componant