Metal finishing Q&As since 1989

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Messy Air Diaphragm Pumps

Has anyone had any success in controlling the oily mist that is emitted from air diaphragm pumps? After a short period of time, we find that the local area is coated with an oily film that is not only ugly but also attracts and holds dirt, making cleanup even more difficult. We know that there are new models on the market that claim to be "oil-less", but we are working with older models. Some years ago, I heard that a shop used straight anti-freeze liquid.

Steve Schulte
Hixson, Inc. - Cincinnati, Ohio, USA
2001

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2001

Hi, Steve.

I've used at least 5 different brands of air diaphragm pumps, and found that even if you are very careful in sizing them and in prepping the air to get the moisture out to make sure they don't freeze, s-t-i-l-l the tendency to stall is their worst weakness.

I'd rather put up with the mess than have a pump stall for lack of lubrication of the shuttle valve. I hope the designers are listening and figuring out some way to accumulate the blow-by to jolt a stalled pump back into running again.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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There is a special lubricant/antifreeze product we use where necessary called "KILL FROST". It comes in 1 gallon plastic jugs available from industrial equipment supply houses, and with the normal types of air oiling devices, in the air line, just ahead of the pump, can be added at the slowest possible adjustment, a couple drops per minute or so, and does the job with a minimum of vapor from the pump exhaust. Where even this much mess is undesirable, try loosely wrapping the exhaust muffler in a disposable absorbent towel made for wiping up oil spills, and periodically replace it with a fresh one. Works good, but absorbent does eventually get saturated, and if not replaced then, can cause the pump to stall too, by blocking the exhaust! W. Carl Erickson
- Rome, New York
2001

I know that this is a late response, but for the benefit of any one else coming to this link with the same problem, here is the easiest solution. Fit an exhaust cleaner, they are available from various pneumatic manufacturers altho I prefer SMC's Unit..

Richard Buddin
Diaphragm Pumps Ltd - UK
2001

You have touched on two items that will work. First install a coalescing filter on your incoming air line to remove oil carry over from the compressor. This will take out some of the water as well. Then a Tanner injection unit putting in Tannergas as a de-icer. This product also comes in a non toxic version that can be used in confined spaces. It has been used in the mining industry for years. Finally an exhaust muffler cleaner from SMC will keep any residue from going on the floor.

Cliff Morrison
C&B Industrial Supplies Ltd. - Dartmouth, Nova Scotia, Canada
2002