ISO 7289:2018

Overview

ISO 7289:2018 specifies requirements and type tests for quick-action couplings with shut-off valves used in gas welding, cutting and allied processes. The standard covers couplings installed between the regulator and the torch (with hoses conforming to ISO 3821 or threaded unions per ISO/TR 28821) and defines design, installation, material and performance requirements so coupling/uncoupling can be performed safely while equipment remains pressurized.

Key topics and technical requirements

• Scope and application: Applies to couplings used between regulator and torch for gas welding, cutting and allied processes.
• Coupling types: Three gas-specific types defined - Type O (oxygen), Type F (fuel gas) and Type N (other welding gases) - to prevent accidental interchange.
• Dimensions and interchangeability: Standardizes critical dimensions (including a minimum length for the internal diameter) so that elements of different gas types are non-interchangeable while couplings of the same type remain interchangeable across manufacturers.
• Shut-off configuration: The shut-off device must be located in the female element; gas-tight sealing is provided on the cylindrical shaft surface.
• Materials and hardness: Materials must meet ISO 9539 requirements. Male elements must be from uncoated material with a surface hardness ≥ 270 HV10 (higher surface-hardness criteria apply for certain coated materials).
• Performance / working requirements:
  • Designed for a maximum working pressure of 2 MPa (20 bar).
  • Type-testing includes pressure-resistance (test pressures up to 4 MPa and 6 MPa specified), gas tightness, pressure drop, flashback resistance, tensile and radial load resistance, and endurance.
• Coupling/uncoupling: Must be operable without tools, resist accidental disengagement (e.g., not by simple rotation or by longitudinal traction < 1 kN), and the shut-off must operate automatically on uncoupling.
• Marking and user instructions: Requirements for identification and instructions for safe use are specified.

Applications and who uses this standard

ISO 7289:2018 is relevant to:

• Manufacturers of welding and cutting torches, regulators and hose assemblies (product design and production).
• Test laboratories and conformity assessment bodies performing type tests and certification.
• Procurement, quality and safety engineers specifying compliant quick-action couplings for workshops, fabrication shops, shipyards and industrial maintenance.
• Equipment installers and maintenance teams ensuring safe installation (female shut-off upstream) and correct gas-specific connections.

Related standards

• ISO 3821 - hoses for gas welding and allied processes
• ISO/TR 28821 - threaded unions recommendations
• ISO 9539 - materials for welding equipment
• ISO 5175-1, ISO 9090, ISO 6150, ISO 15296 - normative references used for testing, vocabulary and related safety/devices

Keywords: ISO 7289:2018, quick-action couplings, shut-off valves, gas welding, cutting, hose ISO 3821, threaded unions ISO/TR 28821, pressure resistance, gas tightness, coupling interchangeability.