The Auto Degassing Valve greatly improves the degassing capabilities of the E-Series metering pumps. The design uses a dual check valve system to maintain proper pump operation to vent gas out the valve and back to the supply source. The ADV retains the full pressure capabilities of the pump.
The Auto Degassing Valve is available as an accessory and can be installed onto any of the 21 sized or smaller EW, EZ, EK or EWN series pumps. Installation between the pump head and the existing manual air vent valve makes field conversions simple, and maintains the functionability of the full manual air vent valve
Principle of Operation
As air or gas is pulled into the pump head, pump operation and gravity help work the gas bubble up through the pump head. Due to system pressure, the trapped gas compresses with each stroke and the discharge check valves will not open causing a gas or air lock condition. The vent of the Auto Degassing Valve, however, is under no pressure and because the discharge valves are above the vent, the gas moves toward the vent with each pump stroke. The design of the double check valve in the ADV limits the amount of liquid that passes through before sealing shut forcing the rest of the volume out the discharge while gravity, coupled with the suction stroke of the pump, reseat the valves for the suction stroke.
Being compressible, as the gas makes its way to the check valves in the ADV, it will quickly purge through the Auto Degassing Valve. Once enough of the gas is purged out the vent, and each pump stroke can overcome the discharge pressure, regular pumping will resume.
During normal operation, with each stroke a small amount of liquid will be ‘vented' out the ADV ensuring flow for the next time gas enters the pump head.
Addition of the ADV onto a metering pump will reduce the rated output of the pump by approximately 15-20% as this extra chemical is pushed through the vent side of the valve and back to the supply tank. The unique design of the ADV relies on the suction stroke of the pump with gravity to create a subtle liquid pull back into the pump head with each stroke enabling the trapped gasses to escape out of the vent. The ADV was designed specifically for suction lift applications.
For more information, please see 
Data Sheet
