ISO 15500-4:2020

Road vehicles - Compressed natural gas (CNG) fuel system components - Part 4: Manual valve

This document specifies tests and requirements for the manual valve, a compressed natural gas (CNG) fuel system component intended for use on the types of motor vehicles defined in ISO 3833. This document is applicable to vehicles (mono-fuel, bi-fuel or dual-fuel applications) using natural gas in accordance with ISO 15403-1. It is not applicable to the following: a) liquefied natural gas (LNG) fuel system components located upstream of, and including, the vaporizer; b) fuel containers; c) stationary gas engines; d) container-mounting hardware; e) electronic fuel management; f) refuelling receptacles.

Véhicules routiers — Composants des systèmes de combustible gaz naturel comprimé (GNC) — Partie 4: Valve manuelle

General Information

• Status: Published
• Publication Date: 12-Nov-2020
• ICS: 43.060.40 - Fuel systems
• Technical Committee: ISO/TC 22/SC 41 - Specific aspects for gaseous fuels
• Drafting Committee: ISO/TC 22/SC 41/WG 3 - Fuel system components and refuelling connector for vehicles propelled by gaseous fuel
• Current Stage: 9092 - International Standard to be revised
• Start Date: 14-Feb-2023
• Completion Date: 13-Dec-2025

Relations

• Revises: ISO 15500-4:2012 - Road vehicles - Compressed natural gas (CNG) fuel system components - Part 4: Manual valve
• Effective Date: 09-Jun-2018
• Revises: ISO 15500-4:2012/Amd 1:2016 - Road vehicles - Compressed natural gas (CNG) fuel system components - Part 4: Manual valve - Amendment 1
• Effective Date: 09-Jun-2018

Overview

ISO 15500-4:2020 specifies tests and requirements for the manual valve used in compressed natural gas (CNG) fuel system components for road vehicles (as defined in ISO 3833). The standard applies to mono‑fuel, bi‑fuel and dual‑fuel vehicles using natural gas in accordance with ISO 15403‑1. It defines essential marking, construction and performance criteria and references general requirements and test methods in ISO 15500‑1 and ISO 15500‑2.

Key topics and technical requirements

• Scope and exclusions: Applies to CNG manual valves for vehicle use; excludes LNG components upstream of the vaporizer, fuel containers, stationary engines, container‑mounting hardware, electronic fuel management and refuelling receptacles.
• Marking: Components must be traceable with manufacturer/agent name or trademark, model/part number, working pressure (and temperature range), and serial number or date code. Additional recommended markings include flow direction, fuel type and certification symbols.
• Construction and assembly: Requirements follow ISO 15500‑1 and ISO 15500‑2. Handles must be securely attached; 90° (quarter‑turn) valves require rigid stops and specific handle orientation; valves shall close when turned clockwise unless otherwise specified.
• Performance tests (referenced procedures in ISO 15500‑2 and described limits in ISO 15500‑4):
  • Hydrostatic strength: Test pressure = 2.5 × working pressure.
  • Leakage: Leakage testing at specified temperature/pressure combinations (e.g., fractions and multiples of working pressure across –40/–20 °C, 20 °C, 85/120 °C conditions).
  • Continued operation: Cycle testing for 10 000 cycles (or 50 cycles for service valves) with downstream pressure adjustments and post‑cycle leakage verification; valves must operate within maximum torque limits in Table 3 (e.g., 1.7–2.8 N·m at max temperature depending on inlet size).
  • Valve stem retention: Must withstand >16.5 N·m counter‑clockwise torque while pressurized at 125% WP (upstream of first‑stage reducer) or 100% WP (downstream) and remain functional.
• Other applicable tests: Excess torque, bending moment, corrosion, ageing (oxygen/ozone/heat), automotive fluids, vibration, brass compatibility and non‑metallic immersion (as indicated in ISO 15500‑2).

Applications and who uses it

ISO 15500-4:2020 is used by:

• CNG valve and component manufacturers for design validation and product certification.
• Automotive OEMs and system integrators specifying compliant CNG fuel systems.
• Testing laboratories and conformity assessment bodies performing performance and safety tests.
• Regulatory agencies, procurement teams and fleet operators requiring standardized safety and traceability for vehicle CNG systems. Practical uses include ensuring safe shut‑off performance, leak tightness, durability under cycling and suitability for vehicle installation and service operations.

Related standards

• ISO 15500‑1: General requirements and definitions for CNG fuel system components
• ISO 15500‑2: Performance and general test methods
• ISO 15403‑1: Natural gas quality for vehicle fuel
• ISO 3833: Vehicle types - terms and definitions

Keywords: ISO 15500-4:2020, CNG manual valve, compressed natural gas, CNG fuel system components, hydrostatic strength, leakage testing, valve stem retention, continued operation.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 15500-4
Third edition
2020-11
Road vehicles — Compressed natural
gas (CNG) fuel system components —
Part 4:
Manual valve
Véhicules routiers — Composants des systèmes de combustible gaz
naturel comprimé (GNC) —
Partie 4: Valve manuelle
Reference number
©
ISO 2020
© ISO 2020
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ii © ISO 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Marking . 2
5 Construction and assembly . 2
6 Tests . 2
6.1 Applicability . 2
6.2 Hydrostatic strength . 3
6.3 Leakage . 3
6.4 Continued operation . 3
6.5 Valve stem retention . 4
Bibliography . 5
Foreword
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This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 41,
Specific aspects for gaseous fuels.
This third edition cancels and replaces the second edition (ISO 15500-4:2012), which has been
technically revised. It also incorporates the Amendment ISO 15500-4:2012/Amd.1:2016. The main
changes compared to the previous edition are as follows:
— serial number or data code becomes mandatory in marking;
— update of 6.4 "continued operation";
— added test for "valve steam retention".
A list of all parts in the ISO 15500 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved

Introduction
For the purposes of this document, all fuel system components in contact with natural gas have
been considered suitable for natural gas as defined in ISO 15403-1. However, it is recognized that
miscellaneous components not specifically covered herein can be examined to meet the criteria of this
document and tested according to the appropriate functional tests.
All references to pressure in this document are considered to be gauge pressures unless otherwise
specified.
1)
This document is based on a service pressure for natural gas used as fuel of 20 MPa [200 bar ] settled
at 15 °C. Other service pressures can be accommodated by adjusting the pressure by the appropriate
factor (ratio).
...