Automatic air valve is installed on the pump discharge and at high points on the force main to prevent air pockets or vacuum conditions from forming in the force main. These valves are automatic devices with floats that open to drive out air when it collects in the valve body. When waste water enters, the float lifts by buoyancy and closes the orifice in the outlet of the valve so the fluid is not drived out.
The most importance of air valve cannot be overlooked. They not only maintain the flow efficiency of a pipeline by venting accumulated air, but also perform many other functions, including surge control after pump power failure by admitting air rapidly to prevent the formation of a vacuum pocket during column separation. Note, however, that maintaining equipment in waste water service is always a challenging and dirty job.
Related recommendation:
Dual Body Combination High Speed Air Vent Valve
Ductile Iron Air Release Valve Single Orifice
Single Opening Exhaust Air Valve
Related recommendation:
Threaded Thermodynamic Disc Type Steam Trap