Safety Pop-Off Valves are designed to protect the pump in the event unloader or regulator valves fail. Should be used in conjunction with a regulator or unloader valve. Brass Body, hardened stainless seat and needle design eliminates weeping. Lightweight, compact design. Internal stainless steel parts provide long life. Assures complete pressure relief. Inlet port is 1/4" MPT. Outlet is 3/4" hose barb.