For low-pressure plumbing applications including air, water, natural gas, and steam. - Galvanized to resist rust and corrosion. Nominal Pipe Size / 1/4 in Pipe Fitting Material / Steel Finish/Coating / Galvanized Class / Class 150 Fitting Connection Type / Female NPT Maximum Operating Pressure / 300 psi @ 150 Degrees F Max. Steam Pressure / 150 psi @ 350 Degrees F Temp. Range / -20 Degrees to 350 Degrees F Plug Construction / Solid Standards / ASME B16.3, ASTM A197