ul-404.8Gauges, Indicating Pressure, for Compressed Gas Service
UL 404
1 Scope
1.1 These requirements cover indicating pressure gauges of the elastic element type usually employed in the high-pressure side of regulators or reducing valves used on compressed gas containers or cylinders of oxygen, hydrogen, nitrogen, and other gases. Such gauges usually have pressure ranges of 0 - 1500, 0 - 2000, 0 - 3000, 0 - 4000, 0 - 5000, or 0 - 6000 pounds per square inch (psi) (0 - 10.34, 0 - 13.78, 0 - 20.68, 0 - 27.56, 0 - 34.47, or 0 - 41.36 MPa).