Auto Degassing Valve (ADV) Auto Degassing Valve The new Auto Degassing Valve greatly improves the degassing capabilities of the E-Series metering pumps. The new 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: Manual air vent valve Vent port Disharge port 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 Automatic Degassing Valve 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 Check Valve before sealing shut forcing the rest of the volume out the discharge while gravity, coupled with the suction stroke of the pump, reseat the Pump head valves for the suction stroke. Discharge check valves 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. Suction port 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

1 Auto Degassing Valve 2 Materials of Construction VC = PVC Housing FKM Seats and Seals Titanium Separation Pin VE = PVC Housing EPDM Seats and Seals Hastelloy C276 Separation Pin VCH = PVC Housing FKM Seats and Seals Hastelloy C276 Separation Pin See Exploded views on www.walchem.com for part numbers Installation: 1. Remove the entire discharge assembly of the pump (MAW, Lock nut, Valve Housing, Valve Guides, Seats and Seals) from the pump head. 2. Install the new Lock Nut, Valve housing, Spacer, two Gaskets and O-ring of the ADV into the pump head. 3. Use the Lock Nut to secure the Auto Degassing Valve...