FIG. 942 DOUBLE ORIFICE AIR RELEASE VALVE​​

Usage for waste & sewage water.
Double orifice air valve that combines both large orifice & small orifice functions within one unit. The large orifice allows air to be expelled from the system during filling of a pipeline and admit air back into the system whenever sub-atmospheric pressure occurs.
Air is vented from the system until liquid enters the valve and lifts the float on its pivot which lifts the plug against the large orifice seat. Pressure within the body holds the plug firmly against the seat. In the event of sub-atmospheric pressure in the system, the liquid level drops causing the float and plug to lower and allow the admission of air.
During normal working of the main the valve releases the air which accumulates under pressure, without escape of fluid. With the main in operation, the float normally holds the orifice button against its seat.
As air enters the body the fluid level is depressed until a level is reached when the float drops, which allows air to vent through the small orifice. The consequent rise in fluid level returns the float and orifice button to its seat.
Efficient low pressure sealing at 0.2bar.
50mm (2″) – 150mm (6″) sizes.