ISO 15500-4:2020

This document specifies tests and requirements for the manual valve, a compressed natural gas (CNG) fuel system component intended for use on the types of motor vehicles defined in ISO 3833.
This document is applicable to vehicles (mono-fuel, bi-fuel or dual-fuel applications) using natural gas in accordance with ISO 15403-1.
It is not applicable to the following:
a)   liquefied natural gas (LNG) fuel system components located upstream of, and including, the vaporizer;
b)   fuel containers;
c)   stationary gas engines;
d)   container-mounting hardware;
e)   electronic fuel management;
f)    refuelling receptacles.