Interstage relief valve pops on high pressure side of Champion

by Tommy
(Wake Forest, NC)

Champion 2 stage  air compressor

Champion 2 stage air compressor

Champion 2 stage  air compressor
Champion air compressor model number label
Champion air compressor showing PRV valves
Champion air compressor high pressure cylinder PRV

Bill,


I have a older Champion 2 stage 175psi max 80 gallon air compressor.

On start up the pressure will build to about 50 psi and then the relief valve on the high pressure side starts releasing.

Noticed that someone had installed 200psi interstage relief valves, I guess to over come the issue instead of trying to fix the real problem.

I since replaced the relief valve with the correct psi of 75.

Now back to the original issue, what would be the most likely cause of the high pressure relief to pop at 50psi?

thanks,

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Oct 23, 2014
Interstage relief valve pops on high pressure side of Champion Air Compressor
by: Tommy

Doug,
Please send me the link you found the manual for my compressor at. I only have a portion of a manual that I was able gather small pieces of information from.

Thanks
Tommy

Oct 22, 2014
PRV, etc
by: Doug in s.d.ca

I see the manual for this is 25 bucks. Do you have it?

It still seems that the HP PRV should be more than 75psi, but in any case, it looks like there must be some failure/obstruction in the HP cylinder.

Depending on your resources, you best get the manual and or a rebuild kit or some gasket material, and take the head off to see what you can see. E.g., a piece of valve or something blocking the outlet.

Oct 22, 2014
Image are loaded
by: Bill

Tommy, I've added your images and the text from your new comment in the ASK forum.

Maybe now that we can see them, we can come up with something.

Bill

Oct 22, 2014
Images
by: Tommy

Bill,

Here are attached photos of my Champion Air Compressor. As you can see, there is a relief valve on each cylinder. The relief valve on the left cylinder (High Pressure) is the one that pops at 50psi and it has a 75 psi relief pressure installed. Each one of these were replaced as there were originally 200psi. I am assuming that these are interstage relief valves? Should they both be 75 psi? The original 200 psi relief valve on the HP side released at 147psi and that is what started me investigating. What are your thoughts on what the problem could be?

thanks,
Tommy

Oct 22, 2014
Pictures
by: Bill

Tommy, to add photos please start a new thread, refer in it to this one, and add up to four images.

Once they come in, I'll move them over to this thread so there is continuity and all folks can see what you and we are talking about.

B.

Oct 22, 2014
hmmm
by: Doug in s.d.ca

Can you direct us to your source for the prv info? It is unclear how both could be 75PSI. I suspect the second one SHOULD be 200, but can't tell because I'm not sure where it is.

Pictures of your unit, or a model number or link to where you got your info may help us understand.

Oct 21, 2014
PRV
by: Bill

So the high pressure PRV is letting go at 75 PSI?

OK, so it's likely a back pressure issue doing that I would think. Sure, it might be the HP valve, but before checking that, maybe pull the tank check valve and make sure it's not crudded up and not allowing good air flow into the tank.

Drain the tank first, off course.

Oct 21, 2014
PRV Lets Go
by: Tommy

Bill,

My compressor, Champion Air-On_Line Model 6.5V80E has a relief valve located on both the HP and LP cylinders. The HP cylinder relief is releasing at around 50psi and the low pressure relief is working fine. The manual I have says that both relief valve should be 75psi. Someone had previously installed 200psi relief valves for what reason I don't know but it too started releasing that is when I started troubleshooting. I now have the correct 75 psi relief valves installed and having the problem as indicated. Do you think the in line check valve could be bad or the intake valves. If intake valves, on the HP or LP side?

Thanks,

Oct 21, 2014
PRV
by: Bill

My understanding was that the PRV that was letting go is on the line between the low pressure and high pressure cylinders.

It is that PRV that I refer to.

B.

Oct 21, 2014
Interstage relief valve pops on high pressure side
by: Tommy

Bill,

For clarification, when you say the intake valve on the second cylinder, are you referring to the low pressure cylinder/side even though the relief that is releasing is on the high pressure side?

thanks,

Oct 21, 2014
PRV lets go
by: Bill

Tommy, for my money the most frequent reason for an inter-stage PRV to start letting go is that the intake valve on the second cylinder isn't working properly, blocking air entry, and back-pressuring the line.

Bill

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What specific type of oil for older Champion air compressor?

by Mike
(Lewistown IL)

First off, I'm working with a standup 80 gal champion air compressor circa 1957. Has worked perfectly until lately. I noticed the oil getting a little discolored so I drained it and replaced it with SAE 30. Now, every time it kicks on, it smokes a little bit and now it's starting to smell. I'm kinda curious if today's standard of compressor oil is different than back then and it's too thin? Should I drain it and use an automotive 30 weight? If not, are there any ideas as to why it's acting up?

Comments for What specific type of oil for older Champion air compressor?

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Mar 08, 2014
oil
by: Doug in s.d.ca

Have you checked

www.industrialaircompressors.biz?

E-mailed?
What did they say?

Mar 08, 2014
oil
by: Doug in s.d.ca

"Maybe I will drain what's in there now and try the full synthetic"

Yes, that's what I'd do, under the circumstances.

Keep us posted, will you please?

Mar 08, 2014
Ok
by: Anonymous

What I took out and what I put in seemed to be of a different consistency. I put in standard 30sae air compressor oil. Now I'm having the problems. I actually have a few bottles of full synthetic Mobil 1 30sae. Maybe I will drain what's in there now and try the full synthetic

Mar 08, 2014
oil
by: Doug in s.d.ca

Are you using synthetic SAE30 non-detergent?

I'd try that, or, you might try "compressor oil" from your local big-box.

Mar 07, 2014
compressor oil
by: Anonymous

the oil i've used for years in all reciprocating compressors is from Grainger, it's a Mobil product and what I like is it's a synthetic oil that's worked well in cold temperatures also. this is a link that should take you right there.

http://www.grainger.com/product/MOBIL-Air-Compressor-Oil-4ZF21?s_pp=false

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