Standards Development

Scope

ISO 23550 specifies safety, construction, performance and testing requirements for controls for gas burners and gas burning appliances for use with gaseous fuels (see definitions).

This document applies to controls with a declared maximum operating pressures up to and including 500 kPa with connections up to and including DN 250. This document provides the general requirements that are intended to be the basis for the specific control standards found in the ISO 23551 and ISO 23552 series. These include the following:

— automatic and semi-automatic shut-off valves;

— pressure regulators;

— valve-proving systems for automatic shut-off valves;

— manual gas valves;

— thermoelectric flame supervision controls;

— multifunctional controls;

— mechanical gas thermostats;

— vent valves;

— fuel/air ratio controls, electronic type (includes liquid fuels).

This document covers type testing only.

This document is also applicable to Gas Quick Connectors (GQC) for use inside appliances with connections up to, and including DN 25, and a maximum operating pressure up to and including 100 kPa. GQCs include:

— tube to tube connections;

— tube to control connections; and

— tube to fitting connections.

This document does not apply to mechanical controls for use with liquid fuels. It is also not applicable to corrosive and waste gases.

Purpose

The need for a revision of ISO 23550 was identified by the TC.

The following changes are planned:

— consideration of renewable and synthetic gases as a fuel type and its effects on controls;

— update and realignment with the relevant parts of IEC 60730-1:2022