ISO 23551-8:2016 specifies the safety, construction and performance requirements for multifunctional controls intended for use with gas burners, gas appliances and similar use, hereafter referred to as "MFC".
ISO 23551-8:2016 is applicable to MFC with declared maximum inlet pressures up to, and including, 50 kPa (500 mbar) of nominal connection sizes up to, and including, DN 150 for use with one or more fuel gases.
MFC consist of two or more functions, at least one of which is a mechanical control, as specified in the relevant control standards.