White substance in the air lines

by Charles Wimer
(Fort Collins, Colordo)

Air line contaminant

Air line contaminant

Hi Bill,

I came across your site and found a lot of good info on it for air compressors and compressed air systems.

I then seen that you have a place to ask questions when you can’t find an answer anywhere else.

The problem I have is I have a strange white substance in my air lines after the oil mist filter and I am unsure of what this white substance is and how to remove it or if I need to.

This is how I got to this situation; I have a large Bel-Aire 80 gallon 5 hp 175psi compressor that I believe had gotten some compressor oil in the lines as I received it manufacture over full on oil. After draining it to the proper level and hooking it up it I installed an oil mist filter and membrane air dryer in the line after the compressor it ran for 8 months.

I then notice that I was getting water at the end of the 40 ft run of line and a 50 ft of air hose.

After draining the air tank and the lines I removed the filter and found that oil had gotten past the oil filter and into the membrane dryer.

I also found the white substance in the lines that starts after the oil filter and goes past the membrane dryer and on into the rest of the system.

I also found the white substance in the two air pressure regulators downstream in the hard lines and it seems to have damaged them as well.

If I install a liquid filter before the oil mist filter to keep liquids out of the line do I need to worry about cleaning all the white substance or will it just stay dry and in place? I have attached a picture for more clarity on my question.

Thank you in advance for your help

Charles Wimer
Charles, I have seen a lot of air lines, and haven't seen any with a white substance, unless there was a lot of water in the lines, and the white substance was in the water that dried, and left the residue.

Tell us a bit about the ambient air around the compressor, particularly, where the air that is entering the intake on the compressor is coming from, and is there any air borne contaminant (like some sort of white dust?) that is being sucked into the compressor intake, through the tank, out the coupler and down the lines. Could that be the problem?


Comments for White substance in the air lines

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Aug 09, 2013
White stuff
by: Doug in s.d.ca

How does this stuff feel? Caked up, powdery...?

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