US Patent 8454058 High pressure fitting for hydrogen applications

High pressure hydrogen fittings and methods of sealing a pipe to a valve body. In one embodiment, the high pressure hydrogen fitting includes a pipe having flange near one end; a nut surrounding the pipe on a low pressure side of the flange, the nut having threads mating with threads on a valve body; a lip seal surrounding the pipe on a high pressure side of the flange, the flange supporting the lip seal, the lip seal pointing toward the valve body, the lip seal having a cylindrical sealing surface, the cylindrical seal surface engaging the valve body; wherein when the pipe containing hydrogen is connected to a valve body, a seal is maintained at a pressure of up to about 87.5 MPa.