Why you should use an advanced filter with an Airmax Compressor

It’s written up in my big thread, but BEFORE I even did an initial power up, I had drained out the original oil, wiped the interior of the crankcase, washed the gasket membrane, completely cleaned out both cylinders, all the valves, and the water separator. It was clean as much as possible of the old oil and its residue. I wanted her in the best condition possible for an anticipated long life of service. It was cleaned of all original run residue & oil.

My very first run was with Chemlube 501. The fill whip, on which you see all this contaminant, was attached after all that. What you are seeing in the above photo is breakdown products of Chemlube 501. Even Chemlube 501 will thermal decompose in the second stage’s temperature and pressure if you have a unit that is putting loads of it into the air stream. Thermal cracked chemlube 501 also smells pretty awful as opposed to the low odor state it arrives. That awful scent really pisses you off, because even though you clean all the visible residue with solvent, the fittings still smell. It also permeates your skin.

80 minutes run time!

I would select a filter that includes hydrocarbon absorption with activated carbon post molecular sieve drying. Both dman1114 and JB’s Alpha incorporate that important, additional function in their cartridges. They also isolate their pressure walls and threads from direct contact with the drying media’s corrosive effects.

The activated carbon stage is what kept all this nasty hydrocarbon out of my tank. If I had only drying media and no activated carbon, the hydrocarbon would have gotten through. There is absolutely no scent of thermal cracked oil at the output of my Alpha. The input end, you saw what it was facing in my earlier pict. Even with thorough alcohol cleaning, that end of the alpha and the fill whip that connected it to the Airmax still smell of the cracked oil.

Personally, I like the Alpha’s PMV being present because the Airmax lacks a PMV function. It’s separator needs all the help it can get and the better the separator works the less water load gets to the drying media. This is especially helpful if you ever fill anything that is below 1600 PSI.

My Bauer’s PMV is set to 3000 PSI. The process is pressurize the compressor to 3,000. The PMV opens. Run dry air through the fill whip to remove residual moisture in it. Then, fill the tank.

Both the Alpha and dman1114 units can mounted vertically. That lets the space in the filter housing below the cartridge & above the bleed valve act as a small, secondary water separator before water (that got through the Airmax’s separator) hits the actual cartridge media. It gives you one more place to mechanically bleed off water before it reaches the drying media. Liquid water directly getting to molecular sieve is not a good thing. The exothermic reaction of liquid water + molecular sieve is super hot..

With the bare bones Airmax, strategy should be to emulate as much functionality of a dive compressor as practical. That industry has a much longer and through experience with air quality, compressor function, filtering, and cylinders than we do on the airgun side. We know less, but use higher pressures. How’s that for irony?

BTW (from that “other” forum) a nice write up about the internals of the Alpha
http://www.airgunnation.com/topic/alpha-vs-diablo-in-line-moisture-filters/page/2/