This part of ISO 15500 specifies general requirements and definitions of compressed natural gas fuel system components, intended for use on the types of motor vehicles as defined in ISO 3833. It also provides general design principles, and specifies requirements for instructions and marking.

This part of ISO 15500 is applicable to vehicles using natural gas in accordance with ISO 15403 (mono-fuel, bi-fuel or dual-fuel applications). It is not applicable to the following:

• liquefied natural gas (LNG) fuel system components located upstream of, and including, the vaporizer;
• fuel containers;
• stationary gas engines;
• container mounting hardware;
• electronic fuel management;
• refuelling receptacles.