Foamy compressor oil

[Winchester]

I recently changed complete oil charge on 2 RDB Plus Frick compressors and I have one that when running will foam completlely over top sight glass and appear the same in the bottom glass. Any insight would be greatly appreciated.

[josef]

Liquid injection oil cooling, check thermal expansion valves+solenoid valve

[Winchester]

Sorry, themosyphon oil cooling.

[josef]

Hi Winchester, you have the suction pipe 2 valves, 1 for manual valve should be closed, 2 strainer + on the return valve, it is sufficient to be open about 2x, offset pressures on 20-30 minutes

[ART KUHN]

Hey,

oil temp ok?
heating rods oke?

Reagards.

[Magoo]

Generally foaming oil indicates either saturated suction or oil is too cold, if too cold check the secondary oil recovery line after coalesars, if that is going hard out, oil is too cold. If the thermo system is controlled by one of those 3 way thermo valves wack it with a large hammer, as they can tend to stick after a prolonged shut down.
thinking outload again.
Magoo

[josef]

Foam although other species (mineral-synthetic) or other oil producers

[TXiceman]

Did you change oil or add a different oil. No matter what the oil manufacturers say, mixing oils in a system can cause oil foaming...I've seen it happen.

Ken

[Winchester]

Oil anylisis came back that oil viscosity was high and change complete charge with same oil.

[Winchester]

Oil temp at 138 running and all oil heating elemets working.

[Winchester]

Amot valve is working and holding a running oil temp. of 138. Oil return from coalescent filters is warm and no oil in sight glass.

[Frank Day]

What is your saturated condensing temp and refrigerant? Condensing temp may be too low!

[nh3wizard]

Are both compressors you changed the oil on running at the same pressures? Were all the filters changed (Oil and coalescent) on both compressors. As TXiceman stated mixing manufacturers oil can cause oil foaming.

[Segei]

This is booster or high stage compressor.

[RANGER1]

Winchester ,
Does your compressor have an economizer conected to comps and what conditions is it running at ?
I think if you touch/feel/ observe frost patterns on and around compressor then you may spot some form of flood back .
Rotor housing should get hotter as it approaches discharge end of machine .
It would be nice to know temps and pressures ie discharge temp , suction / discharge pressures , oil level ( may be low ) ,economizer if any .
Sometimes you can shut a plant down for a few hours and oil can settle in level control columns etc .
Also check for unusual frost or lack of it on control columns on vessels . Float switches become sluggish and probes go haywire causing flood overs .

[Winchester]

This is booster or high stage compressor.

This a booster compressor.

[Segei]

This a booster compressor.

Usually, oil foaming happen when you overcharge oil or when liquid ammonia enter the oil separator. In your case may be thermosiphon heat exchanger has a leak. Check it.

[josef]

You good choice oil filter?

[J.D]

On single stage screws, you will see the oil foam if the discharge pressure drops, such as when condenser pumps or fans start. Is the intemediate pressure stable or is there loads going on and off that may cause pressure flucuations.

J.D

[Frank Day]

Good Call J.D.

Winchester, are you working on a booster high stage plant and are both compressors running at the same suction and discharge conditions or is one high stage and the other low stage?

Frank Day