How a Air compressor makes water why you need a water trap

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Joined: Tue Sep 16, 2008 1:17 pm
Location: Pahrump NV.
PostPosted: Sun Jul 22, 2018 8:33 am
Lots of people don't understand how a Air compressor makes water.

This is a Short film that shows a large Cavity inside filled with Compressed air that once compressed is allowed to decompress rapidly which is what your Air compressor does repeatedly while operating, Its constantly filling with compressed air then decompressing while you use the compressed air. What you are about to see is NOT Smoke this is Condensation in the air Basically a Cloud of water moisture in the air from simple decompression.

Now trapping water is a little more tricky and it does require a bit of science to understand why and how. but basically due to the Hi temperatures of a Compressor in operation will drive the air temperature way up way over a 100 degrees just the compressing of air drives the air temp up.
So to remove the water in the air you need to COOL the air down first which requires 20-30 feet of Pipe after the Compressor tank this is a good area to place a water trap, It doesn't really need to be more than a Large air Tank with a drain to allow the air to briefly expand even though the air is still under pressure it will expand when it hits a Larger area Pipe or an aux tank and when it does it gives off more heat which will allow the water in the compressed air to condensate on the walls of the larger pipe or Tank to collect on the walls to be later drained from the bottom .

I use two expansion tanks one after the other mine are about 6 inches in dia. and about 2 1/2 feet tall connected by 3/4" pipe. I also have a fancy Desiccant air drier on my Booth another 20-30 feet away. I have never had to replace my Desiccant its Indicator is always Blue.

Rapid air cooling from expansion

Hope it helps some guys understand How water is created in there compressors and how to remove it. You don't need a fancy refrigerated air cooler / drier in your Hobby shop.
Dennis Barnett
A&P Mechanic, FCC General radio Telephone Operator
Line Maintenance A&P Mechanic and MOC Tech specialist.

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