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The diffusers description includes a lot of information. Let us describe what is indicated in the description for example of a 9” disc diffuser “Airtech disc diffuser 9″ Ø270 PPGF EPDM+PTFE (2-2.5) ¾” M NPT.
Airtech is the brand name of WTE products for aeration.
Disc diffuser: refers to the shape of the diffusers. Be in mind that on the market are also available, “tube diffusers” “panel diffusers” or even “plate diffusers” It is even possible to discriminate the diffusers based on the bubble size and consequently some diffusers will be “fine” “medium” or “coarse” bubbles.
9” is the conventional size of the membrane diffusers. The diameter of the membrane from one side of the retainer ring to the other side is 224 mm or 8,8”. At the same way if a 12” is offered, you have to expect that the membrane diameter is 299 mm or 11,8”.
Ø270: is the diameter of the diffusers “all out” in mm (10,6”). Use this info to calculate the minimum step between two diffusers. It will be 270 +the space your hands need to mount or to unscrew the diffusers (around 10 cm or 3,9”)
PPGF: is the material of the diffuser body. The most common materials used to mould the diffusers body are PVC (PolyVinyl Chloride), PP (Polypropylene), ABS (Acrylonitrile-Butadiene-Styrene) and PPV (Polypropylene Glass Fibre reinforced). Each material has specific mechanical characteristic and properties. Consider this point when you buy a diffuser especially when they are used in warm environment.
EPDM+PTFE: the membrane of the above diffusers is produced in EPDM (Ethylene-Propylene Diene Monomer) coated with PTFE (PolyTetraFluoroEthylene) but other usual materials are EPDM, Silicone, NBR (Nitrile Butadiene Rubber), Urethane. Membrane has a key role in the durability of the diffusers. EPDM can be safely used with most of the civil sewage, but with industrial wastewater, consider the chemical compatibility of the membrane with the liquid to be treated.
(2-2.5): indicate the perforation size and the gap between two consecutive perforation. The long perforation is the bigger is the bubble generated at constant airflow passing through the perforation. The higher is the gap between two perforations the higher is the mechanical resistance of the membrane, but the price you pay for this character of the membrane is a reduction of the efficiency i.e., you have less perforation on the membrane surface.
Example of perforation 1-1,5
¾” M NPT: indicate the type (Male) and size of the connection of the diffusers.
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