Description The Morrison Bros. 939-0300 1V Fusible Globe Valve 3/4IN Brass Key Features Fusible element integrated into the hand-wheel melts at 165°F causing the valve to close Recommended use with fuel oil and kerosene service 10 PSI maximum operating pressure 1/4″ to 3/4″ sizes 25 PSI maximum operating pressure 1″ size Not intended for use as a block valve, intended as a normally open valve 1/4″, 3/8″, and 1/2″ are UL and ULC listed