TEEJET DIAPHRAGM-TYPE PRESSURE RELIEF VALVE - 1/2" NPT X 300 PSINylon Body with Aluminum Bonnet Interchange 2334878 846012,846012, Net Weight (lbs) 0. 75 Size 1 2 inch NPT Brand TeeJet 8460 Series Diaphragm Type Pressure Relief Valve Bypasses excess liquid. Adjustable to maintain control of line pressure at any pressure within the valves 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