High-pressure piping means gas fuel piping with maximum working pressure greater than 10 bar. High-pressure piping means FC fuel piping with maximum working pressure greater than 1.0 MPa.In conclusion, high-pressure piping refers to pipelines and fittings that are designed to withstand high-pressure fluids and gases. These systems are used in a variety of industries and require specialised materials, fittings, and joints to ensure their safety and reliability.