ISO 18119:2018

Overview - ISO 18119:2018 (Gas cylinders periodic inspection and testing)

ISO 18119:2018 specifies requirements for the periodic inspection and testing of seamless steel and seamless aluminium‑alloy gas cylinders and tubes to verify integrity before re‑introduction into service. It applies to transportable gas cylinders (single or in bundles) intended for compressed and liquefied gases - generally for water capacities from 0.5 L up to 150 L (cylinders) and >150 L (tubes), and, where practical, to cylinders below 0.5 L. The standard excludes acetylene cylinders and composite cylinders. Its principal aim is safe requalification through documented inspection, testing and marking.

Key topics and technical requirements

ISO 18119 covers the full periodic requalification process, including:

• Inspection intervals and procedures - defined requirements for timing and sequence of periodic inspections and tests.
• Preparation and depressurization / de‑valving - safe procedures to prepare cylinders for inspection.
• External and internal visual inspection - examination of body, neck, threads, footrings and internal surfaces.
• Neck and thread inspection - assessment of valve threads and neck conditions, plus remedies for damaged threads.
• Non‑destructive testing (NDT) - ultrasonic testing (UT) procedures, calibration, performance and interpretation; guidance for cylinders with footrings or convex bases.
• Pressure tests - proof pressure and hydraulic volumetric expansion tests, plus acceptance criteria and test equipment requirements.
• Supplementary tests - specific checks for heat‑damaged aluminium‑alloy cylinders, hammer tests on footrings, cleaning procedures.
• Valve and accessory inspection - examination, replacement and re‑valving practices.
• Repair, rejection and decommissioning - definitions of defects, repair limits, rejection criteria and processes to render cylinders unserviceable.
• Final operations and records - drying, painting/coating, retest marking, stamping, next inspection date and record keeping.
• Informative annexes - guidance on test periods, defect evaluation, corrosive gases list, volumetric expansion testing, test date rings and aluminium cleaning.

Practical applications and users

ISO 18119 is intended for organizations responsible for cylinder maintenance, safety and transport compliance:

• Cylinder inspection and testing facilities and service centers
• Gas suppliers and distributors managing cylinder fleets and bundles
• Fleet managers, rental companies and industrial gas users
• Regulatory authorities and transport safety inspectors
• Manufacturers and technical personnel developing inspection procedures

Using ISO 18119 helps ensure safe requalification, consistent periodic inspection and testing, regulatory compliance, and traceable records for return to service.

Related standards

• Replaces and consolidates earlier ISO 6406 and ISO 10461 series (and associated amendment).
• Suitable for reference in UN Model Regulations and for alignment with national transport and pressure‑vessel requirements.