Drawing and Connectionsair diffuser drawing

The standard diffuser arrangement is to have a 1/2" hose tail at one end and a 1/4" cap at the opposite end.  The air supply supply hose provided by Dryden Aqua is 1/2" braided urethane hose or a very heavy duty sinking hose.  The hose is secured to the hose tail by a screw clip.

Materials of construction

The male threaded fittings in the diffusers are manufactured from 316 L stainless steel.  The end cap and the female ring and tail 1/2" hose fittings are manufactured from POM plastic and are supplied with the the diffusers as standard. The diffusers can also be supplied with hose fittings in brass, or 316 L stainless steel as an optional extra.

The diffusers are manufactured from a very heavy duty polyester fabric tube, a nylon distributor hose runs down the centre of the tube. Between the nylon hose and polyester tube there is a ballast comprising of spherical glass beads.

The diffuser is banded using 316 L stainless steel compressed on to the nylon inner tube with a nitride rubber bush and covered in blue compression plastic.

The diffusers may be used in seawater or freshwater, in soft water and water with a hardness and alkalinity over 2000 mg/l.

diffuser end


Solid diffusers have problems with carbonate and iron deposition in the stones which blocks the diffusers.  Solid diffuser are very difficult to clean  and maintain. Flexible membrane diffusers stay largely free of fouling, however they need a heavy frame or are anchored to the base of the aeration tank, this makes the diffusers much more expensive and difficult to handle, it also makes them difficult to use in lagoons.

The Dryden Aqua diffuser is a hybrid unit because it is semi flexible, carbonates and metal oxide precipitates simply crack off the unit. Also because our diffuser has its own internal ballast it does not need to be anchored to the base of the tank. If any cleaning or maintenance is required, the diffuser is simple pulled our of the tank using the air hose. The tank can be full of water and the air blowers running when the diffuser is removed.
Normal operating life of an air diffuser is from 5 to 10 years.

Design pressure and temperature

The diffusers can operate in water from 0 to 50 °C.  The differential pressure when operating at their design air flow rate is 0.1 to 0.2 bar. The differential pressure may increase due to fouling. The diuffsers have been tested up to a differential pressure of 10 bar.

Product details

Item No.DiscriptionDiffuser Weight KgAir Flow m3/hr (+/-20 %)Oxygen Transfer kg of O2/day per diffuser at different depths at 20 °C and 50 % O2 saturation diameter
         2 m  3 m  4 m 32 mm 
70000 0.33 m Diffuser 0.5 1 2 2.5 32 mm
70001 0.66 m Diffuser 1.0 2 4 5.0 6 32 mm 
70002 1.00 m Diffuser 1.5 3 6 7.5 9 32 mm 
70003 1.33 m Diffuser 2.0 4 8 10 12 32 mm
70004 1.66 m Diffuser 2.5 5 10 12 15 32 mm
70005 2.00 m Diffuser 3.0 6 12 15 18 32 mm
70006 2.33 m Diffuser 3.5 7 14 17 21 32 mm
70007 2.66 m Diffuser 4.0 8 16 20 24 32 mm
70008 3.00 m Diffuser 4.5 9 18 22 27 32 mm

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