6815-1/2-50 Piston-Type Pressure Relief/Regulating Valve.
Brass, 1/2" Inlet & Pipe Connection, 50 psi max.
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 large flows.
Also available in 3/4" and in 50 and 300 psi.