ISO/TC 161/WG 4 - Multifunctional Controls

This document specifies safety, constructional and performance requirements for manual gas valves intended for use with gas burners and gas-burning appliances, hereafter referred to as "valves", unless otherwise specified. This document applies to the following types of manual gas valves: — manual gas shut-off valves; — gas burner valves; — appliance connector valves; — delta C valves. This document applies to valves for gas burners and gas-burning appliances of nominal connection size up to and including DN 100 that can be used and tested independently of these appliances using fuel gases, as natural gas, manufactured gas or liquefied petroleum gas (LPG) at inlet pressures up to and including 500 kPa. This document is not applicable to corrosive and waste gases. This document covers type testing only.

This document specifies safety, construction, performance and testing requirements for multifunctional controls with integral overpressure protection safety function (OPSF) intended for use with portable gas appliances. This document is applicable to: — multifunctional controls which consist of a pressure-limiting device and at least one or more controls, including but not limited to a manual gas valve, a pressure regulator and a thermoelectric flame supervision device; and — multifunctional controls with declared maximum operating pressures in normal use, up to and including 500 kPa for use with a butane gas cartridge specified by ISO/TS 21985. This document does not apply to multifunctional controls with OPSF having thread connections for mounting butane gas cartridges. This document covers type testing only.

This document specifies safety, construction, performance and testing requirements for mechanical gas thermostat intended for use with gas burners and gas burning appliances hereafter referred to as “thermostats”. This document applies to mechanical gas thermostats of nominal connection sizes up to and including DN 50 with declared maximum inlet pressures up to and including 50 kPa, for use with natural gas, manufactured gas or liquefied petroleum gas (LPG). It is not applicable to corrosive and waste gases. This document applies to mechanical thermostats: — controlling the gas flow directly or indirectly through an integral gas valve, and which do not require external electrical energy for their operation; — used on gas appliances where the thermostat is not directly exposed to the outdoor environment; and — which are intended for operating control functions. This document covers type testing only.

This document specifies safety, constructional, and performance and testing requirements for thermoelectric flame supervision controls, energized by a thermocouple, intended for use with gas burners and gas-burning appliances, hereafter referred to as “controls”. This document applies to thermoelectric flame supervision controls for gas burners and gas-burning appliances of nominal connection size up to, and including DN 50, that can be used and tested independently of these appliances. These thermoelectric flame supervision controls are suitable for fuel gases, such as natural gas, manufactured gas or liquefied petroleum gas (LPG) at inlet pressures up to and including 50 kPa. It is not applicable to corrosive and waste gases. This document covers type testing only. This document is not applicable to: a) the thermocouple; and b) controls which use auxiliary energy (e.g. electrical energy supplied externally).

This document specifies safety, construction, performance and testing requirements for pressure regulators and pneumatic gas/air ratio pressure regulators intended for use with gas burners and gas-burning appliances. This document applies to pressure regulators and pneumatic gas/air ratio pressure regulators of nominal connection size up to and including DN 250 at inlet pressures up to and including 500 kPa, for use with natural gas, manufactured gas or liquefied petroleum gas (LPG). It is not applicable to corrosive and waste gases. This document is specifically applicable to: — positive, zero and negative pressure regulators which can use auxiliary energy to change the outlet pressure setting; — pneumatic gas/air ratio pressure regulators, which function by controlling a gas outlet pressure in response to an air signal pressure, air signal differential pressure, and/or to a combustion chamber pressure signal; — gas/air ratio pressure regulators, which function by controlling an air outlet pressure in response to a gas signal pressure or a gas signal differential pressure. This document does not cover: — pressure regulators connected directly to gas distribution network or to a container that maintains a standard distribution pressure; — pressure regulators intended to be installed in the open air and exposed to the environment; — mechanically linked gas/air ratio controls; — electronic pressure regulators and gas/air ratio regulators, which are contained in ISO 23552-1. This document covers type testing only. NOTE Annexes A to H reference the relevant annexes of ISO 23550, general requirements and are applicable where required.

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.