Alpha In-Line Moisture Filter

Original price was: $499.00.Current price is: $399.00.


When Filling a PCP airgun or airtank from a Shoebox, Alpha, Omega (or similar inexpensive high pressure compressor without a true water separator filter), a quality in-line moisture filter should be used to remove all oil, water and particulates from the air. This is an absolute must to prevent the accumulation of something that looks like mayonaise inside your tank. We guarantee that we offer the best and most safest filter made for this application. Call in for more information or to purchase.

We gaurantee our AlphaFilter is the best for the following reasons:

1). We use Molecular Sieve, (not Silica Gel); Recognized in the industry as being the “best”, it is used in almost all breathing filters and other types of high pressure filters where one needs to “scrub” the air.

PropertyMolecular SieveCaOCaSO4Montmorillonite ClaySilica Gel
Absorptive Capacity at low H2O ConcentrationsExcellentExcellentGoodFairPoor
Rate of AbsorptionExcellentPoorGoodGoodGood
Capacity for Water @ 77F 40% RHHighHighLowMediumHigh
Separation by Molecular SizesYesNoNoNoNo
Absorptive Capacity at Elevated TemperaturesExcellentGoodGoodPoorPoor

2. Moisture separation works best at High Pressure. When filling a tank with an inline filter, ensure the filter has some kind of the proper valving mechanism to allow the pressure to build up, prior to flow through the filter. The pressure needs to be held back up inside the filter to a point, and then allowed to flow through the filter media. (That’s the reason for the gold thing on the top of our filter). It costs us more, but without the proper valving, the air and moisture basically rushes over the media at low pressures, and doesn’t get scrubbed. Also the filter media needs a “dwell time” as well as high pressure to work best. Simply running air through a cylinder with a filter element doesn’t work well, and using loose packed beads doesn’t work at all. Make sure the filter has the proper valving to allow pressure to build up before the air runs through it.

3. Filters require a place to let out the condensate. If the filter is working, it should be collecting moisture and it needs to be let out immediately. Letting the condensate sit in the filter allows the moisture to saturate the filter media, rendering it useless.

4. One can’t just pack beads in a cylinder for 2 VERY important reasons.

a) It doesn’t work because of “Channeling” : We’d all like to just make a filter that uses cheap beads packed in a cylinder, but the first issue is that without proper packing, “channeling” will occur between the media. Simply put, channeling is the situation where air just goes around the individual filter “beads” instead of being “scrubbed”. In order to work, the media need to be properly “jam packed” into the a container element, and this filter element put in a filter tube. Filter elements are manufactured to be “jam packed”. Putting the media into a tube doesn’t pack it tight enough to prevent channeling at high pressures. Replacement filter elements are inexpensive, so it isn’t an issue.

b) Most importantly SAFETY. NEVER make a high pressure filter where the filter material directly touches the cylinder walls of a high pressure filter. This is filter element 101. The moisture in filter media leaches acid, and hence must not come in direct contact with the filter tube. Acid that leaches out will eventually make it to the walls of the vessel and threads on the end-caps of the filter, weakening them, and eventually causing the high possibility of catastrophic failure. This point can’t be stressed enough.

Points A) & B) are why every high pressure filter uses media that is jam-packed into either a plastic or stainless steel sleeve. So it works, and works SAFELY!

We would rather see you use no filter at all, and ruin an airgun, that use an unsafe product, and risk the dangers of doing so.

Additional information




1 review for Alpha In-Line Moisture Filter

  1. 5 out of 5

    Donna Davis

    Glad I found the alpha filter .its by far the best on the market . My ebay (filter) i had was dangerous. it somehow had some air pressure stuck inside and made loud pop when I opened it to change the media…thats when I went looking and found the alpha. 400 is a small price to pay for safety. Thankyou joe b

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