ISO 12614-2:2021

Overview

ISO 12614-2:2021 - Road vehicles: Liquefied natural gas (LNG) fuel system components - Part 2: Performance and general test methods defines performance requirements and general test methods for LNG fuel system components used on motor vehicles (as defined in ISO 3833). The standard describes design principles, marking and instruction requirements, and a suite of functional tests for components (excluding fuel containers, stationary gas engines, container mounting hardware, electronic fuel management and refuelling receptacles). All pressures are treated as gauge pressures and the baseline working pressure is 1.6 MPa (16 bar) (scalable by a ratio for other system pressures).

Key topics and technical requirements

• Test environment and conditions

  • Default room temperature: 20 °C ± 5 °C; tests normally use inert gas unless otherwise stated.
  • Low-temperature testing uses < −162 °C (LNG/liq. nitrogen) and specified high temperatures (e.g., 85 °C / 120 °C).
  • Pressure tolerances: generally ±5% unless specified.

• Hydrostatic strength

  • Components must not rupture under specified hydrostatic pressure; test pressure applied for at least 3 minutes.

• Leakage (external and internal)

  • Components purged and sealed at 30% working pressure prior to conditioning.
  • Acceptance: bubble-free or leakage < 20 Ncm³/h; specific immersion, helium vacuum or equivalent methods allowed.
  • Test points include 25%, 100% and 150% of working pressure across temperature ranges.

• Mechanical robustness

  • Excess torque resistance: withstand 150% of manufacturer’s specified torque without damage, followed by leakage and hydrostatic checks.
  • Bending moment: defined force application (at 300 mm) and multi-orientation cycling with post-test leak and strength verification.
  • Continued operation (durability): cyclic opening/closing per ISO 12614 series, with defined cycle timing (one open+close within 10 s ± 2 s) and temperature distribution (e.g., 96% cycles at cryogenic temp for components intended for < −40 °C use).

• Other tests

  • Corrosion resistance, oxygen ageing, electrical overvoltage, non-metallic material immersion, vibration resistance, and brass material compatibility.

Applications and users

• Used by vehicle manufacturers, component suppliers, design and validation engineers, independent testing laboratories, certification bodies and fleet operators to:
  • Validate LNG component safety and durability.
  • Specify procurement and quality-assurance test plans.
  • Support regulatory compliance and type-approval for LNG-fuelled vehicles.

Related standards

• ISO 12614-1:2021 (general requirements & definitions)
• ISO 12614-3 (component-specific tests)
• ISO 15500 series (CNG component testing reference)
• ISO 188, ISO 9227 (material ageing and corrosion test methods)
• ISO 3833 (vehicle type definitions)

Keywords: ISO 12614-2, LNG fuel system components, performance and general test methods, LNG testing, hydrostatic strength, leakage testing, LNG vehicle components.