Overview
EN ISO 9090:2019 (CEN adopted) defines acceptable external gas leakage rates and measurement procedures for individual components used in the gas supply to a blowpipe for gas welding, cutting and allied processes. It covers type and routine testing, test pressures, test gases, and measurement methods (including correction procedures). The standard applies to components from the hose outlet or cylinder valve to the blowpipe connection - it does not apply to whole gas supply plants. Individual product standards (e.g., ISO 9012 for some blowpipes) take precedence for specific test details.
Key topics and technical requirements
- Expression of leakage: leakage is given in cubic centimetres per hour (cm3/h) of the gas for which equipment is designed, corrected to standard conditions (23 °C, 1,013 bar).
- Test gases:
- Devices intended for helium and/or hydrogen shall be tested with helium (hydrogen is no longer used as test gas).
- Devices for other gases: dry oil-free air or nitrogen. Routine tests may use air or nitrogen.
- Test pressures:
- Regulators: tested at pressures p1 and p2 as defined in ISO 2503.
- Other equipment (type tests): tested at manufacturer’s maximum working pressure and at 10% of that pressure or 0.5 bar (whichever is lower).
- Routine tests: performed at the pressure that proved most unfavourable during type testing.
- Maximum permissible external leakage rates (total leakage for complete component including inlet connections):
- Regulators: ≤ 10 cm3/h
- Blowpipes: total ≤ 8 cm3/h; leakage through each valve ≤ 4 cm3/h (detailed blowpipe test methods in Annex B)
- Safety devices: ≤ 8 cm3/h
- Quick-action couplings: connected ≤ 10 cm3/h; unconnected female elements ≤ 10 cm3/h
- Devices with combined functions: must meet the most stringent requirement of the constituent functions
- Hose assembly: leakage requirement is specified in the standard (value provided in the full text)
- Measurement & methods: Clause 8 describes measurement principles (immersion method included), test apparatus, procedures and Annex A covers correction of measurements.
Applications and who uses this standard
- Manufacturers of welding, cutting and allied-process equipment (regulators, blowpipes, couplings, safety devices, hose assemblies)
- Test and certification laboratories performing type and routine leakage tests
- Quality, safety and compliance engineers in welding shops and fabrication plants
- Procurement and standards teams verifying supplier conformance and product specifications
- Inspectors and regulatory bodies concerned with welding safety and gas leak risk mitigation
Related standards (referenced)
- ISO 2503 - Pressure regulators for gas welding equipment (test pressures for regulators)
- ISO 15296 - Vocabulary for gas welding equipment
- Product-specific standards (e.g., ISO 9012 for certain hand blowpipes) take precedence for test method details.
Keywords: EN ISO 9090:2019, gas tightness, gas welding equipment, leakage testing, blowpipe leak rate, pressure regulators, quick-action coupling, hose assembly, welding safety.
