Mercer Valve P/N 91-56H11T84U1, Series 9100, Connections 1-1/2"300#RF x 3"150#RF, Orifice H, Seat Teflon, Inlet and Body Carbon Steel, PSIG Pressure Limit 740, Top Closed, Service Gas, PSIG Setting Range 451-700, Soft Seat Safety Relief Valve