The isolation flange is a combination of an isolation ball valve and a companion flange for circulators. The isolation flange allows easy service or replacement of the circulator without the need to drain the system. The isolation flange fits the Bell and Gossett NRF/NBF/SSF wet rotors, Series PL, Series 100, PR and LR circulators. Bell and Gossett Isolation Flange, 1-1/4 in Nominal Size, NPTF, 150 psig, 200 deg F, Handle Actuator, Brass Body, Brass Stem Trim, PTFE Packing/Seat Ring, Chrome Plated, 4-7/16 in Flange, 2-57/64 in Inlet to Outlet Length x 2-5/324-7/16 in Flange, 3-19/64 in Inlet to Outlet Length x 3 in Top to Inlet Center Valve