Overview
EN ISO 7291:2010 (ISO 7291:2010) defines safety, design and test requirements for pressure regulators used in manifold systems for gas welding, cutting and allied processes. It covers regulators for compressed gases up to 30 MPa (300 bar), plus specific gases including dissolved acetylene, LPG, MPS (methylacetylene‑propadiene mixtures) and carbon dioxide (CO2). The standard applies to regulators used in cylinder manifold assemblies and is not applicable to pressure regulators fitted directly to gas cylinders (see ISO 2503).
Key topics and technical requirements
- Scope & terminology: Definitions for manifold regulators and related components are aligned with ISO 15296 vocabulary.
- Materials & manufacturing: Materials must conform to ISO 9539 and components for oxygen service must be cleaned and degreased to prevent internal ignition.
- Gas-specific design:
- Oxygen regulators: Designed to resist ignition; pass ignition testing (see clause 9.4.4).
- Acetylene regulators: Constructed to withstand acetylene decomposition and subject to decomposition testing (clause 9.4.6).
- Filters: A non‑removable (tool‑required) particle filter is required upstream of the valve; the filter must retain particles ≥ 0.1 mm.
- Pressure-adjusting device: Must prevent the valve from being held fully open (e.g., spring fully compressed) and must not allow adjustment that causes the pressure relief device to vent.
- Pressure gauges: Upstream and downstream gauges required in accordance with ISO 5171; gauge connections must follow applicable thread standards and also withstand acetylene decomposition testing (clause 9.4.7).
- Performance & testing: Detailed type tests for functionality, mechanical resistance, gas tightness and durability of markings are specified (see Clause 9). Flow rates are measured in m3/h corrected to a standard atmosphere (ISO 554).
- Gas tightness: Internal and external leakage limits and test methods reference ISO 9090.
Practical applications and users
- Manufacturers of gas welding and cutting equipment designing manifold pressure regulators.
- Welding equipment designers and R&D teams ensuring regulatory compliance and safe product performance up to 300 bar.
- Quality, test and certification labs performing type tests and safety verification according to ISO 7291 clauses.
- Procurement, safety officers and workshop managers specifying safe manifold systems for welding, cutting and allied processes.
- Standards bodies and regulatory authorities aligning national rules with the EN ISO version.
Related standards
- ISO 2503 - Regulators fitted directly to gas cylinders (excluded by ISO 7291)
- ISO 5171 - Pressure gauges for welding/cutting
- ISO 9539 - Materials for gas welding equipment
- ISO 15296 - Vocabulary for gas welding equipment
- ISO 9090 - Gas tightness of welding equipment
- ISO 554 - Standard atmosphere for flow corrections
Using EN ISO 7291:2010 ensures safety, interoperability and consistent testing for high‑pressure manifold regulators in professional welding and cutting environments.