ISO 23551-10:2025

Overview

ISO 23551-10:2025 - Safety and control devices for gas burners and gas-burning appliances - Particular requirements - Part 10: Vent valves - specifies the safety, constructional, performance and testing requirements for normally open automatic vent valves used in gas control trains. The standard applies to valves up to DN 100 (4") and with declared maximum operating pressures up to 500 kPa, for use with gaseous fuels such as natural gas, manufactured gas and LPG. It covers electrically operated valves and fluid-actuated valves where the fluid control is electrically actuated, and includes valves fitted with open position indicator switches (OPS). ISO 23551-10:2025 covers type testing only and excludes corrosive and waste gases.

Key Topics and Requirements

The standard provides detailed, testable requirements across construction, performance and electrical aspects. Major technical topics include:

• Classification and definitions - scope, classes of control and types of DC-supplied controls.
• Construction requirements - housing, moving parts, breather holes, vent limiters, seals, materials and corrosion resistance.
• Connections and sizes - nominal connections up to DN 100, threads, flanges and fittings suitable for gas appliance integration.
• Performance tests - leak-tightness, rated flow rate, torsion and bending resistance, opening/closing forces and times, delay time, and endurance.
• Durability and endurance testing - cyclic operation and functional reliability over life expectancy.
• Hydrostatic withstand test - verification of pressure integrity.
• Electrical and EMC requirements - protection by enclosure, switch and connector requirements, immunity and surge tests for electrically actuated valves.
• Open position indicator switch (OPS) - functional and test requirements for position feedback.
• Type testing scope - procedures and tolerances for consistent verification.

(Key SEO terms: ISO 23551-10:2025, vent valves, gas burners, leak-tightness, rated flow rate, endurance test, EMC)

Applications and Who Uses This Standard

ISO 23551-10 is practical for organizations involved in the design, manufacture, testing and certification of gas appliance safety components:

• Valve and gas control manufacturers - design and validate automatic vent valves to comply with international safety requirements.
• Test laboratories and certification bodies - perform type testing and conformity assessment per the standard.
• Appliance OEMs and system integrators - select compliant vent valves for gas burners and gas-burning appliances.
• Regulatory authorities and safety engineers - reference for compliance, approvals and risk assessment.
• Procurement and quality teams - specify valves with verified performance for commercial and industrial gas applications.

Related Standards

ISO 23551-10:2025 is part of the broader ISO 23551 series on safety and control devices for gas burners and appliances. Manufacturers and test labs should also consult relevant national appliance standards and other ISO parts addressing complementary gas control devices and testing methods.