ISO 11119-4:2016

Overview

ISO 11119-4:2016 - "Gas cylinders - Refillable composite gas cylinders - Design, construction and testing - Part 4" - specifies requirements for fully wrapped fibre-reinforced composite (Type 3) gas cylinders with load-sharing welded metallic liners. It covers cylinders from 0.5 L to 150 L water capacity and a maximum test pressure of 450 bar for storage and transport of compressed or liquefied gases. Liners may be welded stainless steel, ferritic steel or aluminium alloy and are overwrapped with carbon, aramid, glass fibre (or combinations) in a resin matrix. Cylinders have a minimum design life of 15 years (cylinders with test pressure ≤ 60 bar have unlimited design life). The standard excludes seamless liners (see ISO 11119-2) and removable protective sleeves.

Key topics and technical requirements

• Materials and construction: requirements for welded metallic liners and composite overwrap materials (carbon, aramid, glass fibres) and compatible matrices.
• Design & manufacture: submission of design documentation, manufacturing controls and quality levels for welds and liners.
• Type approval & prototype testing: detailed test suite for design approval, including proof pressure, hydraulic volumetric expansion, liner burst/integrity, full cylinder burst, ambient and environmental cycling, flaw, drop, high-velocity impact (gunfire), fire resistance, salt water immersion, torque, leak and environmentally assisted stress rupture tests.
• Batch inspection & production testing: procedures for liner and overwrap material testing, sample testing and criteria for failure and corrective actions.
• Marking & documentation: cylinder identification, markings and certification requirements to support regulatory compliance.
• Design life and applicability: minimum 15-year design life; limitations and exclusions (no seamless liners, no removable sleeve requirements).

Practical applications and users

ISO 11119-4 is intended for worldwide application where lightweight, high-pressure composite gas cylinders are required. Typical users and stakeholders:

• Cylinder designers and manufacturers producing Type 3 composite cylinders
• Test laboratories and certification bodies performing type approval and batch testing
• Gas producers, distributors and end-users (industrial, medical, diving, transport)
• Regulators, transport authorities and conformity assessment organizations
• OEMs integrating composite cylinders into systems (vehicles, breathing apparatus, portable storage)

Adopting ISO 11119-4 helps ensure safety, repeatable performance, international acceptance and regulatory alignment for composite gas cylinders.

Related standards

• ISO 11119-1, ISO 11119-2, ISO 11119-3 (other parts of the composite cylinder series)
• ISO 11623 (periodic inspection and re‑testing of composite cylinders)
• ISO 11114-1, ISO 13341, ISO 13769, ISO 18172-2, ISO 20703 and other normative references cited for materials, welding and testing methods

Keywords: ISO 11119-4, composite gas cylinders, fully wrapped cylinders, load-sharing welded liner, Type 3 cylinders, cylinder testing, gas cylinder design, cylinder standards.