ISO 15500-9:2012

INTERNATIONAL ISO
STANDARD 15500-9
Second edition
2012-04-15
Road vehicles — Compressed natural gas
(CNG) fuel system components —
Part 9:
Pressure regulator
Véhicules routiers — Composants des systèmes de combustible gaz
naturel comprimé (GNC) —
Partie 9: Régulateur de pression
Reference number
©
ISO 2012
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s
member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International
Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 15500-9 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 25, Vehicles
using gaseous fuels.
This second edition cancels and replaces the first edition (ISO 15500-9:2001), which has been technically revised.
ISO 15500 consists of the following parts, under the general title Road vehicles — Compressed natural gas
(CNG) fuel system components:
— Part 1: General requirements and definitions
— Part 2: Performance and general test methods
— Part 3: Check valve
— Part 4: Manual valve
— Part 5: Manual cylinder valve
— Part 6: Automatic valve
— Part 7: Gas injector
— Part 8: Pressure indicator
— Part 9: Pressure regulator
— Part 10: Gas-flow adjuster
— Part 11: Gas/air mixer
— Part 12: Pressure relief valve (PRV)
— Part 13: Pressure relief device (PRD)
— Part 14: Excess flow valve
— Part 15: Gas-tight housing and ventilation hose
— Part 16: Rigid fuel line in stainless steel
— Part 17: Flexible fuel line
— Part 18: Filter
— Part 19: Fittings
— Part 20: Rigid fuel line in material other than stainless steel
iv © ISO 2012 – All rights reserved

Introduction
For the purposes of this part of ISO 15500, all fuel system components in contact with natural gas have been
considered suitable for natural gas as defined in ISO 15403. However, it is recognized that miscellaneous
components not specifically covered herein can be examined to meet the criteria of this part of ISO 15500 and
tested according to the appropriate functional tests.
All references to pressure in this part of ISO 15500 are considered to be gauge pressures unless otherwise specified.
1)
This part of ISO 15500 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). For example, a 25 MPa (250 bar) service pressure system will require pressures to be multiplied by 1,25.
5 2
1) 1 bar = 0,1 MPa = 10 Pa; 1 MPA = 1 N/mm .
INTERNATIONAL STANDARD ISO 15500-9:2012(E)
Road vehicles — Compressed natural gas (CNG) fuel system
components —
Part 9:
Pressure regulator
1 Scope
This part of ISO 15500 specifies tests and requirements for the pressure regulator, a compressed natural gas
(CNG) fuel system component intended for use on the types of motor vehicles defined in ISO 3833.
This part of ISO 15500 is applicable to vehicles (mono-fuel, bi-fuel or dual-fuel applications) using natural gas
in accordance with ISO 15403.
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.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
ISO 15500-1, Road vehicles — Compressed natural gas (CNG) fuel system components — Part 1: General
requirements and definitions
ISO 15500-2, Road vehicles — Compressed natural gas (CNG) fuel system components — Part 2: Performance
and general test methods
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 15500-1 and the following apply.
3.1
lock-up pressure
stabilized outlet pressure of the regulator at 0 (zero) flow
4 Marking
Marking of the component shall provide sufficient information to allow the following to be traced:
a) the manufacturer’s or agent’s name, trademark or symbol;
b) the model designation (part number);
c) the working pressure or working pressure and temperature range;
d) the maximum outlet pressure.
The following additional markings are recommended:
— the direction of flow (when necessary for correct installation);
— the type of fuel;
— electrical ratings (if applicable);
— the symbol of the certification agency;
— the type approval number;
— the serial number or date code;
— reference to this part of ISO 15500.
NOTE This information can be provided by a suitable identification code on at least one part of the component when
it consists of more than one part.
5 Construction and assembly
The pressure regulator shall comply with the applicable provisions of ISO 15500-1 and ISO 15500-2, and with
the tests specified in Clause 6 of this part of ISO 15500.
The components downstream of the pressure regulator shall be protected from exposure to full upstream
pressure. The pressure relief valve used for this purpose shall reset after relieving.
A pressure relief valve may be integral to the pressure regulator.
The pressure regulator shall have a factory-set maximum outlet pressure. The maximum outlet pressure rating
and the inlet working pressure rating shall be marked on the regulator.
6 Tests
6.1 Applicability
The tests required to be carried out are indicated in Table 1.
2 © ISO 2012 – All rights reserved

Table 1 — Applicable tests
Test procedure as Specific test requirements
Test Applicable
required by ISO 15500-2 of this part of ISO 15500
Hydrostatic strength X X X (see 6.2)
Leakage (external) X X X (see
...