SMA Products TEEJET DIAPHRAGM-TYPE PRESSURE RELIEF VALVE - 1/2" NPT X 300 PSI - 878-846012 Features: 8460 Series Diaphragm Type Pressure Relief Valve Bypasses excess liquid. Adjustable to maintain control of line pressure at any pressure within the valve’s operating range. Selected pressure setting firmly held in place by locknut. Extra large valve passages to handle full flow from supply line. Positive locknut to hold adjustment screw firmly in place. Not affected by jarring and vibration. TechSpecs: Brand: TeeJet Connection: NPT Connection Size: 1/2 Inch Connection Specification: 1/2" Female NPT Material: Nylon / Aluminum Max PSI Rating: 300 PSI Spray Valve Category: Pressure Regulating Valves Spray Valve Type: Manual Valves This is an aftermarket part.