Overview
ISO 11326:2024 - Ships and marine technology - Test procedures for liquid hydrogen storage tank of hydrogen ships - establishes general inspection and test requirements for liquid hydrogen (LH2) cargo tanks on hydrogen carrier ships. It applies specifically to Type C independent metallic double‑wall tanks with vacuum insulation up to 1 000 m3 and to tanks designed to carry pure para‑hydrogen (≥95% content). The standard defines design appraisal, material and welding inspection, hydrostatic and pneumatic testing, tightness and insulation checks, cold‑spot assessment, visual inspection, marking and test reporting.
Key topics and technical requirements
- Scope and applicability: Type C independent tanks, vacuum‑insulated, capacity ≤1 000 m3; testing aligned with IGC Code containment technology requirements.
- Design appraisal: Submission and approval of tank drawings and material specifications by owner or classification society; example drawing lists in Annex C.
- Material inspection: Material property testing across service temperature range (normally up to ~45 °C and down to at least 5 °C below minimum design temperature); hydrogen embrittlement and compatibility testing per ISO 11114‑4.
- Welding inspection: Shell and dome butt welds to be full‑penetration where practicable; mandatory non‑destructive testing (radiography per ISO 17636‑1/2). Where radiography is not possible, use penetrant (ISO 3452‑1), magnetic particle (ISO 9934‑1) or approved ultrasonic methods.
- Hydrostatic and pneumatic tests: Hydrostatic test at ≥1.5× design pressure with water temperature at least 30 °C above material nil‑ductility transition temperature; hold time 2 h per 25 mm thickness (minimum 2 h). Pneumatic tests (when required) at 1.25× MAWP with special safety considerations.
- Other tests: Tightness, insulation performance, cold‑spot tests, visual inspection, marking and comprehensive test reporting. Annexes A–E provide guidance, procedures, report templates and example tank concepts.
Practical applications and users
ISO 11326:2024 is intended for stakeholders in maritime hydrogen logistics and ship construction:
- Shipowners and cargo operators planning hydrogen carrier vessels
- Classification societies and flag administrations assessing conformity and approving designs
- Shipyards and tank manufacturers producing Type C vacuum‑insulated LH2 tanks
- Testing authorities and surveyors conducting type tests, NDT and hydrostatic/pneumatic tests
- Regulatory bodies and maritime safety professionals implementing safe hydrogen transport practices
Implementing ISO 11326 helps ensure safe, consistent testing of liquid hydrogen storage tanks, supporting maritime decarbonization initiatives and commercial deployment of hydrogen shipping.
Related standards
Normative references include: ISO 11114‑4, ISO 17636‑1, ISO 17636‑2, ISO 3452‑1, ISO 9934‑1, ISO 23208. The standard should be used alongside the IGC Code and relevant IMO guidance.
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