Need help with a rotary screw compressor

[BullfrogJohnson]

My new to me service truck has an ingersoll rand VHP90CMH hydraulic driven rotary screw compressor. I am having an issue with really excessive oily water discharge in my air lines. The compressor has 630hrs on it and I just serviced the oil and all filters but it didn't make much of a difference.

Any ideas?

 

[pop pop]

Not familiar with your unit, but the really large ones have an oil separator with a serviceable element. How about yours?

 

[BullfrogJohnson]

Mine has an oil separator filter which I just changed and the has an external coalescing filter in the discharge pipe. I can clean the coalescing filter and run the compressor once and it will be full of milky oil again

 

[Fixnair]

Either your separator is bad or the scavenge line check valve is not working and allowing oil laden air to flow back into your air discharge.

 

[unashamedlaborer]

I'm not super familiar with your unit, but does it have a screw on seperator, or is it a element in the sump?

 

[unashamedlaborer]

Either your separator is bad or the scavenge line check valve is not working and allowing oil laden air to flow back into your air discharge.

Basically... Seperator failure, scavenge failure (obstructed orifice/check valve, tube too short, etc), or running consistently without 60psi or more. That is the way you pass oil with a screw

 

[BullfrogJohnson]

I'm not super familiar with your unit, but does it have a screw on seperator, or is it a element in the sump?

Screw on filter separator.

I think I have more than one problem though. The compressor never unloads. It builds 180psi then just vents out what I think is a safety blow off valve right next to the oil separator .

I will try to take some pictures cause I can't find any info on the compressor.

 

[unashamedlaborer]

Yeah you got more issues for sure. If you can get me a model serial number on that unit I can get a book for you and walk you through it.

 

[BullfrogJohnson]

At initial start up it will sometimes build to 180psi then unload and purge from the bottom brass fitting. Then the compressor will kick back in and build to 180 then will not unload and continuosly vent from the top brass fitting.

The rest of the time it will just build to 180 and continuosly vent from the top brass fitting until I shut it off. Which I know cant be good becuase I have been told you never want to shut down a rotary screw compressor when its loaded.

 

[unashamedlaborer]

Yeah. Looks like a mess. I can't even see the airend in those pics.
Basically from what I can see it is using an aux valve and a pilot valve for controls. And the obvious drive side which is just the PTO. Check the inlet valve to make sure it isn't stuck open, other than that get me a model number and a serial number.

 

[BullfrogJohnson]

Yeah. Looks like a mess. I can't even see the airend in those pics.
Basically from what I can see it is using an aux valve and a pilot valve for controls. And the obvious drive side which is just the PTO. Check the inlet valve to make sure it isn't stuck open, other than that get me a model number and a serial number.

Forgive my ignorance, but when you say inlet valve you are talking about the piece on top of the screw housing that acts like a carburetor?

Where would I find the serial number? The model is a VHP90CMH.

 

[unashamedlaborer]

Forgive my ignorance, but when you say inlet valve you are talking about the piece on top of the screw housing that acts like a carburetor?



Where would I find the serial number? The model is a VHP90CMH.

Yes. Inlet is the "throttle body" the serial number is usually on a metal tag with the model number. On stationary machines it is always on one of the outside panels.

 

[BullfrogJohnson]

Hers the s/n tag

 

[DDunkle]

Did you ever find the solution to your problem??? I'm having the same problem with my vhp90cmh. I can adjust the pressure as high as I need but it's constantly blowing past the pop off.

 

[dnschmidt]

Isn't this why Ingersoll-Rand has service centers? Why guess when they have people available who's sole job is to fix air compressors.