ISO 15501-2:2016 PDF

Overview

ISO 15501-2:2016 specifies test methods for verifying the minimum safety requirements for compressed natural gas (CNG) fuel systems in road vehicles (as defined in ISO 3833). It is the Part 2 companion to ISO 15501‑1 (safety requirements) and focuses on practical tests for system functionality after installation, covering cylinder mounting strength, leak tightness, functional operation and receptacle mounting.

Key topics and technical requirements

• Cylinder mounting strength tests
  • Inertia (dynamic) test: cylinders mounted to vehicle/body or body part; cylinders filled to at least 90% of 20 MPa (200 bar) capacity (density 0.2 kg/l); trolley deceleration measured with channel frequency class CFC 60 (ISO 6487); deceleration maintained for ≥30 ms.
  • Static test: applies a traction force F = (M + 0.9 ρ V) a to the cylinder centre of gravity; force applied within 0.2 s, held ≥0.2 s.
  • Alternative methods: compliant crash tests or approved calculation methods may be accepted.
  • Acceptance: cylinders must remain attached and not interfere with seat structure; calculations require authority approval.
• Leak test
  • Per-vehicle test after installation at ambient temperature.
  • System upstream of the first-stage regulator pressurized at 1 MPa (10 bar) ±0.1 MPa and then 20 MPa (200 bar) ±1 MPa; inspect connections with gas detector or foam; no bubbles for 3 minutes or leak rate