1、 ISO 2012 Road vehicles Compressed natural gas (CNG) fuel system components Part 13: Pressure relief device (PRD) Vhicules routiers Composants des systmes de combustible gaz naturel comprim (GNC) Partie 13: Dispositifs de limitation de pression INTERNATIONAL STANDARD ISO 15500-13 Second edition 2012
2、-04-15 Reference number ISO 15500-13:2012(E) ISO 15500-13:2012(E) ii ISO 2012 All rights reserved COPYRIGHT PROTECTED DOCUMENT 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, in
3、cluding photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs 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 copyrightiso.org Web www.iso.org Publ
4、ished in Switzerland ISO 15500-13:2012(E) ISO 2012 All rights reserved iii Contents Page Foreword iv Introduction .vi 1 Scope 1 2 Normative references . 1 3 T erms and definitions . 1 4 Marking . 2 5 Construction and assembly . 3 6 Tests 3 6.1 Applicability 3 6.2 Hydrostatic strength . 3 6.3 Leakage
5、 4 6.4 Bending moment . 4 6.5 Continued operation . 4 6.6 Accelerated life 5 6.7 Benchtop activation 6 6.8 Thermal cycling . 7 6.9 Condensate-corrosion resistance 7 6.10 Flow capacity 8 7 Production batch inspection and acceptance testing . 8 Annex A (normative) Determination of fusible material yie
6、ld temperature and PRD activation temperature . 9 Bibliography . 11 ISO 15500-13:2012(E) 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
7、 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 col
8、laborates 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 S
9、tandards. 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
10、 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 15500-13 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 25, Vehicles using gaseous fuels. This second edition cancels and replace
11、s the first edition (ISO 15500-13:2001), 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
12、 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
13、 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 iv ISO 2012 All rights reserved ISO 15500-13:2012(E) Part 20: Rigid fuel line in material other than stainless steel ISO 20
14、12 All rights reserved v ISO 15500-13:2012(E) 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 specificall
15、y 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. This part of ISO 15500 is based on a service
16、 pressure for natural gas used as fuel of 20 MPa 200 bar 1) 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. 1) 1 bar = 0,
17、1 MPa = 10 5Pa 1 MPa = 1 N/mm 2 . vi ISO 2012 All rights reserved INTERNATIONAL STANDARD ISO 15500-13:2012(E) Road vehicles Compressed natural gas (CNG) fuel system components Part 13: Pressure relief device (PRD) 1 Scope This part of ISO 15500 specifies tests and requirements for the pressure relie
18、f device (PRD), 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 applicab
19、le 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
20、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 sy
21、stem 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 T erms and definitio ns For the purposes of this document, the terms and definitions given in ISO 15500-1 and the
22、 following apply. 3.1 activation pressure rupture pressure pressure, as specified by the pressure relief device (PRD) manufacturer, at which a PRD is designed to activate to permit the discharge of the cylinder 3.2 activation temperature temperature, as specified by the pressure relief device (PRD)
23、manufacturer, at which a PRD is designed to activate to permit the discharge of the cylinder ISO 2012 All rights reserved 1 ISO 15500-13:2012(E) 3.3 fusible material metal, alloy, or other material capable of being melted where the melting is integral to the function of the pressure relief device (P
24、RD) 3.4 parallel-combination relief device pressure relief device (PRD) activated by high temperature or pressure acting separately NOTE This device may be integrated into one device that has independent pressure-activated and thermally-activated parts. It may also be formed by two independent devic
25、es (one pressure-activated and one thermally-activated) that act independently. Each part of the device shall not interfere with the operation/activation of the other part. The device shall be able to vent the content of the cylinder through any one of the parts of the PRD independently. The device
26、shall be able to vent the content of the cylinder if the pressure- and thermally-activated parts open simultaneously 3.5 pressure-activated relief device pressure relief device (PRD) activated by pressure 3.6 burst disc rupture disc operating part of a pressure-activated pressure relief device (PRD)
27、 which, when installed in the device, is designed to burst at a predetermined pressure to permit discharge of the cylinder 3.7 series-combination relief device pressure relief device (PRD) activated by a combination of high temperature and pressure acting together 3.8 thermally-activated relief devi
28、ce pressure relief device (PRD) activated by high temperature 3.9 yield temperature temperature at which the fusible material becomes sufficiently soft to activate the device and to permit discharge of the cylinder NOTE 1 There are several possible scenarios for a vehicle involved in a fire. The PRD
29、 is intended to reduce the risk of cylinder rupture under most of these scenarios while keeping a low risk of accidental activation. Experience shows that the best solution depends on the type of cylinder the PRD is mounted on. NOTE 2 The suggested configuration for PRDs is parallel-combination or t
30、hermal relief device for every type of cylinder. Series PRDs may only be used in type 1 steel cylinders. 4 Marking If the PRD is a stand-alone component, marking shall provide sufficient information to allow the following to be traced: a) the manufacturers or agents name, trademark or symbol; b) the
31、 fusible material yield temperature or PRD activation temperature (see Annex A), and the rupture disc pressure rating or activation pressure, as appropriate; c) the type of relief device (thermally-activated, series-combination, parallel-combination, etc.). If there is a possibility that the PRD cou
32、ld be installed with the flow in the wrong direction, the PRD shall be marked with an arrow to show the direction of flow. 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. 2 ISO 2012 All rights reser
33、ved ISO 15500-13:2012(E) 5 Construction and assembly The PRD 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. 6 Tests 6.1 Applicability The tests required to be carried out are indicated in Table 1. Table
34、1 Applicable tests Test Applicable Test procedure as required by ISO 15500-2 Sp eci fic t est requirement s of this part of ISO 15500 Hydrostatic strength X X X (see 6.2) Leakage X X X (see 6.3) Excess torque resistance X X Bending moment X a X X (see 6.4) Continued operation X X X (see 6.5) Corrosi
35、on resistance X X Oxygen ageing X X Electrical over-voltages X X Non-metallic material immersion X X Vibration resistance X X Brass material compatibility X X Accelerated life X X X (see 6.6) Benchtop activation X X X (see 6.7) Thermal cycling X X X (see 6.8) Condensate-corrosion resistance X X X (s
36、ee 6.9) Flow capacity X X X (see 6.10) aThis test is to confirm proper design and construction of stand-alone, externally-threaded PRD designs and is not required if the PRD is internally imbedded in the valve body. 6.2 Hydrostatic strength 6.2.1 Housing The manufacturer shall either physically test
37、 the housing or prove its strength by calculation. 6.2.1.1 Test procedure 6.2.1.1.1 Inlet passage strength One piece shall be tested with pressure applied to the inlet, with the internal releasing components in the normally closed position. Pressure-activated elements such as burst discs may be modi
38、fied, replaced with a plug or removed for the purpose of this test. The test shall be performed according to the procedure given in ISO 15500-2 using a pressure of 2,5 times the working pressure at 20 C 5 C. ISO 2012 All rights reserved 3 ISO 15500-13:2012(E) 6.2.1.1.2 Outlet passage strength The ou
39、tlets or venting orifices shall be plugged in a suitable way, without affecting the housing resistance. The internal triggering components such as fusible material or rupture discs shall be removed or otherwise opened or activated. Pressure shall be applied to the inlet of the device. The test shall
40、 be performed according to the procedure given in ISO 15500-2 using a pressure of 1,25 times the working pressure or the working pressure upstream of the outlet passage, whichever is greatest. 6.2.2 Fusible material 6.2.2.1 Test procedure Test the fusible material in the PRD (thermally-activated or
41、combination) with water at 20 C 5 C using the following procedure. a) Subject three randomly selected test specimens to a constant pressure of 1,2 times the working pressure for 30 min. For series-combination relief devices, the burst disc shall not be removed. For parallel- combination relief devic
42、es, only the thermally-activated part of the device shall be tested. During the test, the fusible material shall not begin to extrude out of the PRD. b) Increase the pressure at a rate of 0,5 MPa/s (5 bar/s) to 60 MPa (600 bar), or to the pressure at which the fusible material starts to extrude. 6.2
43、.2.2 Requirement If the extrusion of the fusible material begins at less than 45 MPa (450 bar), the device is considered to have failed the test. 6.3 Leakage Follow the procedure for testing leakage given in ISO 15500-2, using the test temperatures and pressures given in Table 2, below. The PRD shal
44、l be either bubble-free or have a leakage rate 2 Ncm 3 /h. Table 2 Test temperatures and pressures Temperature C Pressure MPa bar 40 or 20 15 150 82 or higher 26 260 6.4 Bending moment The purpose of this test is to confirm proper design and construction of stand-alone, externally-threaded PRD desig
45、ns. Test the PRD according to the corresponding procedure given in ISO 15500-2. 6.5 Continued operation 6.5.1 Test procedure a) Randomly select five test specimens. b) Cycle the PRD according to Table 3, with water at between 10 % and 100 % of the working pressure, at a maximum cyclic rate of 10 cyc
46、les per minute. 4 ISO 2012 All rights reserved ISO 15500-13:2012(E) Table 3 Test temperatures and cycles Temperature C Cycles 82 or higher 2 000 57 2 18 000 6.5.2 Requirements Following the test, there shall be no extrusion of the fusible material from the PRD. At the completion of the test, the PRD
47、 shall comply with the requirements of 6.3 and 6.7. The rupture pressure will be 75 % and 105 % of the activation pressure of a PRD not subjected to any previous testing. 6.6 Accelerated life 6.6.1 General Fusible materials can creep and flow within the operating temperature range of natural gas veh
48、icle PRDs. Accelerated-life testing is performed to verify that the rate of creep is sufficiently low in order that the device can perform reliably for at least one year at 82 C and for at least 20 years at 57 C. Accelerated-life testing shall be performed on new PRD designs or designs in which the
49、fusible material melt temperature or device activation mechanism is modified. For devices not using activation materials that can creep, testing and analysis shall be performed to verify that the device will perform reliably for at least one year at 82 C and at least 20 years at 57 C. 6.6.2 Test procedure a) Place the test specimens in an oven or liquid bath, holding the specimens temperature to within 1 C throughout the test. b) Elevate the pressur
