Features Fitting is interchangeable with black cast-iron or steel. For low-pressure plumbing applications including air, water, natural gas, and steam. Nominal Pipe Size / 3/8 in Pipe Fitting Material / Malleable Iron Class / 150 Fitting Connection Type / Male NPT Temp. Range / -20 Degrees to 366 Degrees F Plug Construction / Cored Standards / ASME B16.14, ASTM A197, UL Listed