Overview
SIST EN ISO 11439:2013 (ISO 11439:2013) defines minimum requirements for lightweight, refillable high‑pressure cylinders used for the on‑board storage of compressed natural gas (CNG) as a fuel in automotive vehicles. The standard applies to seamless steel, seamless aluminium‑alloy and non‑metallic cylinder constructions (it explicitly does not cover stainless‑steel cylinders). ISO 11439:2013 uses 200 bar as a reference working pressure, although other working pressures may be used. The service conditions exclude external loadings such as those from vehicle collisions.
Keywords: ISO 11439, SIST EN ISO 11439:2013, natural gas cylinders, high pressure cylinders, on‑board storage, CNG.
Key technical topics and requirements
- Cylinder types and scope
- Designations: Type 1, Type 2, Type 3, Type 4 (metal, hoop‑wrapped, fully‑wrapped, composite constructions).
- Materials and construction
- Permitted materials: seamless steel, aluminium alloy, non‑metallic liners/composites. Stainless steel is excluded.
- Design and service conditions
- Reference working pressure (200 bar) and allowance for alternative ratings.
- Service environment factors: temperature range, gas composition, and design filling cycles.
- External surface requirements and limitations (no collision loading coverage).
- Testing, inspection and type approval
- Prototype testing, batch testing and tests on every cylinder.
- Non‑destructive examination (NDE), ultrasonic examination and fracture performance considerations.
- Type approval procedure, documentation (design/manufacturing data, specification sheet) and type approval certificates.
- Manufacturing controls and quality
- Construction/workmanship requirements, batch acceptance certificates, and failure handling.
- Marking and dispatch
- Mandatory marking and preparation for shipment to ensure traceability and safe handling.
Practical applications
- Ensuring design and manufacturing compliance for vehicle fuel systems that use CNG.
- Guiding prototype validation, production testing and type approval for on‑board gas cylinders.
- Informing procurement, inspection and maintenance procedures for fleets, OEMs and cylinder manufacturers.
- Supporting safety assessments, regulatory compliance and certification activities for CNG vehicles.
Who should use this standard
- Automotive OEMs and vehicle systems engineers
- Cylinder designers and manufacturers (metal and composite)
- Certification and testing laboratories
- Regulatory authorities, inspection bodies and fleet operators
- Maintenance and safety personnel involved with CNG fuel systems
Related standards and governance
- Prepared by ISO/TC 58 (“Gas cylinders”) in collaboration with CEN/TC 23 (“Transportable gas cylinders”).
- EN ISO 11439:2013 is the adopted European version and supersedes earlier editions (EN ISO 11439:2000).
Using ISO 11439 helps stakeholders achieve consistent safety, performance and regulatory alignment for high‑pressure on‑board natural gas storage in automotive applications.