Most modern air filtration systems utilize disposable chemical cartridges. Some dive shops still prefer to use bulk chemicals to repack their own steel towers or to use repackable stainless liners within aluminum housings. Although somewhat time-consuming and inconvenient, repacking can be economical when compared to disposable cartridges.
B.A.S. sells high quality bulk filtrants for repacking purposes.
Chemicals Available Include:
BAS 070-J-HOP2 HOPCALITE 300
A Brown/ Black, granule composed of a manganese dioxide based catalyst that oxidizes carbon monoxide (CO) in diving air to the more tolerable carbon dioxide (CO2). The latter gas will then be absorbed and removed by avtivated carbon. Use Hopcalite whenever:
(a) The quality of your air intake is questionable, ie. in metropolitan/ industrial areas etc., or
(b) the compressor operating conditions are marginal causing it to run hot or pump for extended periods.
NOTE: Hopcalite is deactivated by moisture, so it must always be placed after the dessicant in the filtration train, but before the charcoal. Active charcoal will remove the (CO2) from the compressed air stream.
BAS-07-R-RAF-01-205374 ACTIVATED CARBON
A specialized form of charcoal, this is the final filtering agent which removes tastes and odors from your compressed air. It aborbs oil and water vapor, chlorine, nitrous oxide, and small amounts of carbon monoxide and carbon dioxide. NOTE: Activated carbon should be the final chemical in the filtration train and must always be preceeded by dessicants. When damp, the effectiveness of charcoal is reduced and may even release previously absorbed contaminants. Also, wet activated carbon of even high quality may form small amounts of Sulfuric Acid which in time can do serious damage to the inside of a filter housing.
BAS-07-13X MOLECULAR SIEVE 13 X
Molecular sieves are a group of chemicals known as Zeolites which have outstanding filtration abilities. Their chemical structure is a narrow, rigid, and uniform crystalline lattice which has such a precise pore size that it restricts the movement of substances based upon their molecular size. Even small molecules such as water can enter the filter but are retained by the lattice hence the name "Molecular Sieve". Molecular sieves are highly effective filtrants for moisture, nitrogen oxide, oil vapor, and limited amounts of carbon monoxide and dioxide. Variety 13X is the best fomulation for processing diver's air because it is designed to trap water vapor.
BAS-07-D111 O-RING LUBRICANT: Dow-Corning Silicone grease valve lubricant and sealant is a chemically inert high pressure seal lubricant.
BAS also has a line of filter towers which utilize disposable cartridges. BAS has final seperator columns, back-pressure regulators and various other accessories available for many different type of compressor systems. The filter towers are constructed from high tensile 7075 aluminum for 5000 PSI and 6000 PSI services. Each filter tower has easy to open threaded, o-ring sealed end caps.
Final Seperator towers, also called a coalescers, fit between the compressor and the chemical towers to mechanically dry the air to less than 1% moisture. A manual vent on the bottom of the column allows the oil/water sludge to be periodically drained off. Without adequate final seperation, the effectiveness of the chemical filters is impaired and the useful life of chemical filter cartidges will be dramatically shortened. All units are designed for a 6000 PSIG service and come without a drain valve.
Short Filter Towers (14") use a 10" disposable chemical cartidge to clean the compressed air. The threaded end caps make replacing the cartridges a swift and simple task. Each tower will process about 12,000 cu.ft. of air per cartridge.
Tall Filter Tower (33") will treat about 22,000 cu.ft. of air per 27" filter cartridge.