Overview
ISO 19078:2013 - "Gas cylinders - Inspection of the cylinder installation, and requalification of high pressure cylinders for the on‑board storage of natural gas as a fuel for automotive vehicles" - defines visual inspection, installation and requalification requirements for high‑pressure natural gas cylinders used on vehicles. It applies to cylinders manufactured to ISO 11439 and provides acceptance, permitted rework, or rejection/destruction criteria when manufacturer guidance is absent. The standard is intended for safe on‑board storage of compressed natural gas (CNG) and supports consistent inspection practice for NGV fleets, service providers and regulators.
Key Topics and Technical Requirements
- Scope and definitions: Clear terminology for cylinder types (CNG‑1 to CNG‑4), components, damage levels (Level 1, 2, 3), liner, resin, delamination, etc.
- Inspection bodies and inspectors: Requirements for organizations and qualified personnel who perform inspections.
- Inspection equipment and preparation: Guidance on tools and procedures required before examination.
- Cylinder, valve and PRD inspection: Visual checks, valve and pressure relief device (PRD) evaluation, and marking verification.
- Damage assessment and requalification: Criteria for identifying Level 1 (minor), Level 2 (repairable or further evaluation) and Level 3 (condemned) conditions; guidance on allowed rework or destruction.
- Additional checks for composite cylinders: Specific inspection points for CNG‑2, CNG‑3 and CNG‑4 composite constructions (e.g., delamination, fibre damage).
- Installation and mounting inspection: Verification of mounting brackets, straps, gas‑tight housings and venting to ensure safe on‑board installation.
- Condemned cylinders and destruction: Procedures and considerations for cylinders declared unfit for service.
- Informative annexes: Practical guidance such as depressurization/purging, inspection checklist examples and hydrostatic/internal inspection considerations.
Practical Applications and Users
ISO 19078 is practical for:
- Inspection bodies and certified inspectors performing periodic visual examinations and requalification of NGV cylinders.
- Vehicle and cylinder manufacturers referencing acceptance/rejection criteria where manufacturer guidance is absent.
- Fleet operators and maintenance workshops establishing inspection checklists, installation audits and cylinder replacement policies.
- Regulators and safety authorities harmonizing inspection rules for on‑board CNG storage.
Keywords: ISO 19078, gas cylinders inspection, CNG cylinders, natural gas vehicle (NGV), requalification, cylinder installation, PRD inspection, ISO 11439.
Related Standards
- ISO 11439 - high pressure cylinders for on‑board NGV storage (design/qualification)
- ISO 15500‑13 / 15500‑15, ISO 15501‑1 / 15501‑2 - CNG system components and safety/test requirements
- ISO 25760 - safe removal of valves from gas cylinders
Use ISO 19078 as the inspection and acceptance framework alongside design and periodicity guidance found in ISO 11439.