Overview
EN ISO 18119:2018/A1:2021 is an amendment to the international standard on periodic inspection and testing of seamless steel and seamless aluminium‑alloy gas cylinders and tubes. Adopted by CEN in May 2021, Amendment 1 (A1) updates inspection criteria, adds terminology and clarifies acceptance/rejection guidance for defects found during internal and external inspection. The amendment is intended for national adoption across CEN member bodies and works alongside the base ISO 18119:2018.
Key topics and technical requirements
- New abbreviated term: introduction of the flaw depth ratio (a/t) expressed as a percentage for defect assessment.
- Hazard‑specific inspection: heightened attention required for cylinders containing flammable, oxidizing, corrosive or toxic gases during internal inspection; Annex C now lists gases corrosive to steel cylinder material.
- Corrosiveness note clarified: corrosiveness in Table A.1 is defined relative to human tissue (ISO 13338), not necessarily cylinder material.
- Ultrasonic thickness checks: when defects reach limiting depth or extent, remaining wall thickness must be verified with ultrasonic measurement; authorities may authorize lower-than-guaranteed wall thickness based on severity and safety factors.
- Defect sizing guidance: ISO/TR 22694 and Figures B.6/B.7 are referenced to evaluate acceptable flaw sizes. Specific allowances include:
- If a/t ≤ 5%, the flaw length may be extended for the cylinder’s parallel length.
- For seamless steel and aluminium‑alloy cylinders, linear flaws with depth ≤ 0.05 t are acceptable “whatever the length” (see Figures B.6/B.7).
- Figure B.7 includes length markers (15 mm, 30 mm, 100 mm) used in aluminium‑alloy evaluation.
- Annex update: Annex C retitled to emphasize gases corrosive to steel cylinder material.
Applications and who uses it
This amendment is essential for:
- Inspection bodies and test stations performing periodic inspections and decision-making on accept/reject.
- Cylinder manufacturers and refurbishers implementing inspection regimes and repair criteria.
- Gas suppliers, transporters and end users managing cylinder maintenance, risk assessment and compliance.
- Regulators and competent authorities setting national acceptance thresholds and authorizations.
Practical uses include defect assessment, ultrasonic wall‑thickness verification, risk mitigation for hazardous gas services, and harmonising national inspection practices with international requirements.
Related standards
For authoritative procedures and full technical details, obtain the complete standard from your national standards body or CEN.
