Watts RK 770 CK4 8 Part of the RK 770 Series Z100F 8NH 225 psi pressure relief valve 225 psi pressure relief valve is designed to relieve thermal expansion in fire protection systems Specifications Air Precharge 12 PSI Air Valve Yes Bladder Material Butyl Brand Watts Buy American Act Compliant NO Color Gray Diameter 21 IN EAN 098268219593 Electricity Required No Fuel Gauge No Inlet Connection Size 1 1 4 IN Inlet Connection Size Metric 32 MM Inlet Connection Type Female Threaded Inlet Thread Type NPT Lead Free Not In Scope Liner Material Does Not Apply To Product Maximum Operating Temperature Fahrenheit 220 Maximum Working Pressure PSI 100 Mount Type Free Standing Orientation Vertical Part Number 0066613 Series ETX Stand Included Yes Tank Acceptance 24 This 8 IN check valve repair kit for series 770 is designed to protect drinking water supplies from dangerous cross connections in accordance with national plumbing codes and water authority requirements Specifications Kit Type Check Kit Lead Free YES Product Group BACKFLOW KITS UPC 098268385991