compressor problem - repair

[bigchrisb]

Having some issues with my Bauer Utilis, and wanted to pick a few brains for possible solutions before I take her to the compressor doctor.

Problem: Compressor runs fine until output pressure comes up to about 50 bar / 700 psi - about where the 2nd stage cylinder can boost it to. Then a knocking noise starts (akin to the noise when first starting the compressor, when the third stage floating piston dosent have adequate back-pressure). At that point, the head temp and leaving temp on the 2nd stage shoot up dramatically, the output falls off considerably, and sometimes the 2nd-3rd stage pressure relief valve on the line vents.

I have pulled the third stage apart, and cant find too much visibly wrong with it. Have also pulled the 2nd-3rd stage line off the 3rd stage inlet, and it flows freely (i.e, I dont think its blocked).

At this point, I have tried the obvious things that come to mind, to no avail. Any suggestions on where to go from here? I suspect that it might be a valving issue on the third stage - any comments?

Thanks in advance,

Chris.

 

[Scuba_Steve]

Are you SURE about the third? You've gone this far already. As a total guess by a w4nker, I wouldn't toss the PSI relief valve venting problem too far away as an good indicator. Can we assume head temp, relief valve venting is an indication of a restriction/lack of flow down stream of the V/Valve.

Let us know how you make out.

.

 

[tbrady]

The most common problem in any compressor is leaky or broken valves. Sometimes the bad valve will be in the stage before or after what you suspect. A leaking OPV mostly indicates a leaking intake valve in the following stage. Also, don't overlook a problem in an autodrain system. (This has bitten me more than once).

 

[COVCI]

Having some issues with my Bauer Utilis, and wanted to pick a few brains for possible solutions before I take her to the compressor doctor.

Problem: Compressor runs fine until output pressure comes up to about 50 bar / 700 psi - about where the 2nd stage cylinder can boost it to. Then a knocking noise starts (akin to the noise when first starting the compressor, when the third stage floating piston dosent have adequate back-pressure). At that point, the head temp and leaving temp on the 2nd stage shoot up dramatically, the output falls off considerably, and sometimes the 2nd-3rd stage pressure relief valve on the line vents.

I have pulled the third stage apart, and cant find too much visibly wrong with it. Have also pulled the 2nd-3rd stage line off the 3rd stage inlet, and it flows freely (i.e, I dont think its blocked).

At this point, I have tried the obvious things that come to mind, to no avail. Any suggestions on where to go from here? I suspect that it might be a valving issue on the third stage - any comments?

Thanks in advance,

Chris.

If the 3rd stage intake valve is faulty, it can cause the 2nd stage to overheat, 2nd stage safety valve to blow and fail to provide enough pressure for the floating piston to function properly. Replace the 3rd stage intake valve and see if that fixes the issue.

Hope this helps.

Chris
COVCI

 

[bigchrisb]

Yep, turned out to be stuffed valves in the third stage, both the intake and exhaust. Getting the valves replaced, should see me right.