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TECHNICAL REFERENCE TR 12: 2003 NATURAL GAS VEHICLES

Compressed natural gas (CNG) vehicle refuelling stations All rights reserved. Unless otherwise specified, no part of the Technical Reference may be reproduced or utilised in any form or by any means, electronic or mechanical, including photocopying and microfilming, without permission in writing from the SPRING Singapore at the address below: Programme Director Standardisation Department SPRING Singapore 2 Bukit Merah Central Singapore 159835 Telephone: 62786666 Telefax: 62786667 Email: stn@spring.gov.sg ISBN 9971-67-XXX-X

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First published, 2003 NOTE 1. Users of this Technical Reference should refer to the relevant professional or experts for any technical

advice on the subject matter. SPRING Singapore shall not be liable for any damages whether directly or indirectly suffered by anyone as a result of reliance on this Technical Reference.

2. Compliance with this Technical Reference does not exempt users from legal obligations.

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Contents

Page

Foreword ________________________________________________________________________ 5

TECHNICAL REFERENCE

1 General __________________________________________________________________ 6

1.1 Scope____________________________________________________________________ 6 1.2 Objective _________________________________________________________________ 6 1.3 Normative references _______________________________________________________ 6 1.4 Refuelling station types ______________________________________________________ 7 1.5 Approvals_________________________________________________________________ 8 1.6 New designs and innovations _________________________________________________ 8

2 Terms and definitions ______________________________________________________ 10

3 Component requirements ___________________________________________________ 14

3.1 General _________________________________________________________________ 14 3.2 Compressors _____________________________________________________________ 14 3.3 Gas storage containers _____________________________________________________ 14 3.4 Valves and piping _________________________________________________________ 14 3.5 Overpressure protection ____________________________________________________ 15 3.6 Pressure gauges __________________________________________________________ 16 3.7 Electrical equipment and wiring_______________________________________________ 16 3.8 Dispensers_______________________________________________________________ 16

4 Installation of equipment ____________________________________________________ 18

4.1 Location of major equipment _________________________________________________ 18 4.2 Installation of compressors __________________________________________________ 20 4.3 Installation of CNG storage system____________________________________________ 20 4.4 Installation of piping________________________________________________________ 21 4.5 Installation of dispensers____________________________________________________ 22 4.6 Installation of overpressure protection _________________________________________ 22 4.7 Security and damage protection ______________________________________________ 22 4.8 Emergency shut-down______________________________________________________ 23 4.9 Site lighting ______________________________________________________________ 23 3.10 Risk assessment of total installation ___________________________________________ 23

5 Mother – daughter refuelling stations __________________________________________ 24

5.1 Mother-daughter refuelling station configurations _________________________________ 24 5.2 Mobile gas storage ________________________________________________________ 24 5.3 Mobile compressors _______________________________________________________ 25 5.4 On-site location of compressors and gas storage_________________________________ 26 5.5 On-site notices____________________________________________________________ 26 5.6 Risk assessment of installations ______________________________________________ 26

6 System installation – Safety provisions _________________________________________ 26

6.1 Safety devices for overpressure protection______________________________________ 26 6.2 Signs and notices _________________________________________________________ 27 6.3 Fire protection ____________________________________________________________ 27 6.4 Indoor installation _________________________________________________________ 27 6.5 Safety management _______________________________________________________ 28

7 System commissioning _____________________________________________________ 29

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7.1 General _________________________________________________________________ 29 7.2 Installation approvals_______________________________________________________ 29 7.3 Compressors _____________________________________________________________ 29 7.4 Piping___________________________________________________________________ 30 7.5 Electrical controls _________________________________________________________ 30 7.6 Gas system controls _______________________________________________________ 30

8 Refuelling station operation__________________________________________________ 30

8.1 Vehicle refuelling procedure _________________________________________________ 30 8.2 Security of dispensers at public refuelling stations ________________________________ 31 8.3 Security of mobile gas storage areas __________________________________________ 31 8.4 Emergency procedure and drills ______________________________________________ 31 8.5 Inspections and maintenance ________________________________________________ 31 8.6 Scheduled tests ___________________________________________________________ 32

9 On-site work procedures ____________________________________________________ 32

9.1 Work procedures __________________________________________________________ 32 9.2 Supervision ______________________________________________________________ 32 9.3 Records _________________________________________________________________ 32 9.4 Standing rules for work on site _______________________________________________ 33 9.5 Maintenance, inspection and testing ___________________________________________ 33 ANNEXES A List of regulatory authorities _________________________________________________ 34 B Requirements for compressors ______________________________________________ 35 C Typical layout of static gas storage units _______________________________________ 37 D Typical arrangement of refuelling station valving system___________________________ 38 E Vehicle refuelling procedure_________________________________________________ 39 TABLES Table 4.1 Separation distances from CNG gas storage units ____________________________ 18 Table 4.2 Separation distances from dispensers______________________________________ 19 Table 5.1 Mobile gas storage attachment design factor ________________________________ 24

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Foreword

This Technical Reference was prepared by the Working Group on Compressed Natural Gas Vehicles appointed by the Technical Committee on Engineering Support under the direction of the General Engineering and Safety Standards Committee. This Technical Reference is now endorsed under the national standardisation programme, which is coordinated by the Standards, Productivity and Innovation Board (SPRING) and guided by an industry-led Singapore Standards Council. This Technical Reference is not to be regarded as a Singapore Standard. This Technical Reference is made available for provisional application over a period of two years, but does not have the status of a Singapore Standard. The aim is to use the experience gained to modify the Technical Reference so that it can be adopted as a Singapore Standard. Users of the Technical Reference are invited to comment on its technical content, ease of use and any ambiguities or anomalies. These comments can be submitted using the feedback form provided at the end of the Technical Reference and will be taken into account in the review of the publication. At the end of the two years, the Technical Reference will be reviewed by the CNGWG to discuss the comments received and to determine its suitability as a Singapore Standard. Submission for approval by the Standards Council as a Singapore Standard will be carried out only upon agreement after review. This Technical Reference has been compiled from a number of established national and international standards, taking into account the latest technology developments, as well as operating, industrial and regulatory conditions specific to Singapore. To promote international harmonisation - thus ease of application, good availability and affordability of products - the terminology and requirements have been aligned where possible with the latest relevant ISO standards or the applicable equivalent national standards. Whilst it is inevitable that there will be discrepancies among different international and national standards, industry experience indicates they have by and large provided a satisfactory history of safety and performance. Thus this Technical Reference also accommodates the acceptance of components, systems and assembly methods which vary from those specified in it, but which comply with accepted alternative national and international standards. In addition, components need not be directly approved in Singapore. Acceptance of foreign approvals, at the discretion of Singapore’s natural gas vehicle industry and regulatory authorities, will improve the availability of safe and affordable components from a wide range of supply sources. It is intended that work on CNG refuelling stations and their associated equipment is performed only by qualified CNG gas fitters. The training of such personnel may be conducted at accredited vocational training institutions. The registration/licensing of qualified personnel may be conducted by a suitable regulatory authority or industry body. This Technical Reference is not to be regarded as being either a design specification or an instruction manual for untrained persons. The requirements are intended to be used in conjunction with, but not take precedence over, any statutory regulations which may apply. While great care and extensive research has gone into the preparation of this Technical Reference, the Committee cannot accept responsibility for any inadequacies. Furthermore, compliance with this Technical Reference does not in any way remove the responsibility from persons involved in work associated with a refuelling station for ensuring at all times that the facility is in a safe condition. In line with international practice, the terms “normative” and “informative” have been used in this Technical Reference to indicate the status of an annex. A “normative” annex constitutes a provision for mandatory compliance, while an “informative” annex is only for information and guidance.

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Compressed natural gas (CNG) vehicle refuelling stations 1 General

1.1 Scope This Technical Reference applies to the design, construction and operation of a compressed natural gas refuelling station operating on pipeline quality gas. Classification of hazardous areas shall be in accordance with AS/NZS 2430.3 as applied to natural gas compression, storage and handling. Where other standards are referred to in this Technical Reference, the reference shall be taken to include all current amendments. Subject to the approval of the relevant regulatory authorities, non-public fleet refuelling stations and special purpose refuelling stations may employ designs, layouts and components that are different from those specified in this Technical Reference. 1.2 Objective The objective of this Technical Reference is to provide designers, manufacturers, installers and regulatory authorities with technical requirements for compressed natural gas vehicle refuelling stations so as to provide functional, safe installations. 1.3 Normative references The normative documents, listed in Annex A, contain provisions which, through reference in this text, constitute provisions of this Technical Reference. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this Technical Reference are encouraged to investigate the possibility of applying the latest editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. American standards ANSI/AGA NGV 1 Compressed natural gas vehicle (NGV) fueling connection devices ANSI/IAS NGV 2 Basic requirements for compressed natural gas vehicle (NGV) fuel containers ASTM A 53 Specification for pipe, steel, black and hot-dipped, zinc-coated welded and

seamless ASTM A 269 Specification for seamless and welded austenitic stainless steel tubing for general

service NFPA 68 Guide for venting of deflagrations SAE J1453 Fitting – O-ring face seal Australian standards AS/NZS 2430.3 Classification of hazardous areas. Part 3 – Specific occupancies AS 2832 Guide for the cathodic protection of metals. Part 1- Pipes, cables and ducts

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British standards BS 806 Specification for the design and construction of ferrous piping installations for and

in connection with land boilers. BS EN 837 Pressure gauges. Part 1: Bourdon tube pressure gauges. Dimensions, metrology, requirements and

testing. Part 2: Selection and installation recommendations for pressure gauges. BS 2050 Specification for electrical resistance of conducting and antistatic products made

from flexible polymeric material Canadian standards CSA B51 Part 2 Boilers, pressure vessels, and pressure piping code. Part 2: High pressure

cylinders for the on-board storage of natural gas as a fuel for automotive vehicles ISO standards ISO 834 Fire resistance tests – Elements of building construction. Parts 1 to 11. ISO 11439 Gas cylinders - High pressure cylinders for the on-board storage of natural gas as

a fuel for automotive vehicles ISO 15500-17 Road vehicles – Compressed natural gas (CNG) fuel system components. Part 17:

Flexible fuel line. ISO 15403 Natural gas – Designation of the quality of natural gas for use as a compressed

fuel for vehicles Singapore standards CP 5 Code of practice for electrical installations. CP 13 Code of practice for mechanical ventilation and air conditioning in buildings. CP 29 Fire hydrant systems and hose reels SS 217 Industrial safety signs SS 232 -1 Portable fire extinguishers – Description, duration of operation, Class A and B fire

tests. TR 10 Compressed natural gas (CNG) vehicle workshop and personnel requirements TR 11 Compressed natural gas (CNG) vehicle component and installation requirements. 1.4 Refuelling station types CNG refuelling stations can be classified according to the speed of vehicle filling: (a) Fast fill, where refuelling is carried out over a period of less than 10 minutes per vehicle. (b) Slow fill, where refuelling can take hours per vehicle. (c) A combination of fast fill and slow fill. Alternatively, they can also be classified based on logistical operation: (d) On-line refuelling station, where the gas is supplied by pipeline reticulation to the site. (e) Mother station, where gas supply to the CNG compressor is reticulated by pipeline to site. (f) Daughter station, where gas supply to the fuel dispenser or the station compressor is

transported by means other than pipeline reticulation to site.

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1.5 Approvals 1.5.1 The refuelling station siting and layout shall meet the requirements of all relevant regulatory authorities. Such approvals shall be obtained before site construction and equipment installation begin. 1.5.2 All equipment used shall comply with existing statutory requirements. NOTE: The list of the relevant regulatory authorities is given in Annex B. 1.6 New designs and innovations New materials, designs, configurations or procedures which differ from those specified in this Technical Reference, but which give equivalent results, may also be used, provided they are approved by the relevant regulatory authority.

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2 Terms and definitions For the purposes of this Technical Reference, the following definitions apply: 2.1 Approved, approval Approved by, or approval of, the relevant regulatory authority. 2.2 Authority (or regulatory authority) The authority having statutory powers to control any aspect of the installation and use of equipment described in this Technical Reference. Different authorities exercise different aspects of control, e.g. gas supply, electricity supply, pressure equipment safety, fire safety, land use, environmental protection, etc. 2.3 Bulk tank A gas container defined as a pressure vessel, i.e. manufactured under a pressure vessel standard, not a gas cylinder standard. 2.4 CNG Compressed natural gas. 2.5 Commercial fuel transaction A transaction where payment is determined based on the metered quantity of CNG at the dispenser for each individual fill. This type of transaction normally applies only to public refuelling stations. 2.6 Cubic metre (m3) Unless otherwise stated, all volumes of gas or CNG are expressed in this Technical Reference as standard cubic metres, i.e. in the Standard Metric Condition (MSC). 2.7 Daughter refuelling station A refuelling station which gets it gas supply not from a natural gas reticulation network but from mobile gas storage delivered from mother stations. 2.8 Dispenser A unit for dispensing CNG fuel. 2.9 Fire resistance level / Fire Rating Level (FRL) The rating of the ability of a structure subjected to a standard fire to fulfil for the stated periods of time the required load bearing capacity, integrity and thermal insulation, as defined in a fire resistance test standard. These times, in minutes, are used to express the rating of the structure, eg 240/240/240 FRL.

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2.10 Gas storage unit A group of gas cylinders or tanks manifolded together. 2.11 Hazardous area An area as defined in AS 2430.3 or an approved alternative national standard. 2.12 Ignition source A source of energy sufficient to ignite a flammable atmosphere and includes naked flames, exposed incandescent material, electric welding arcs, and electrical or mechanical equipment not approved for use in hazardous areas. 2.13 Installation owner The company owning the refuelling station equipment and installation. 2.14 Isolating valve A quarter-turn manual shut-off valve. 2.15 Master shut-off valve A quarter-turn valve to permit the quick isolation of all downstream equipment from the gas storage system. 2.16 Maximum developed pressure The pressure developed by the contents of a gas cylinder in equilibrium at the maximum service temperature. 2.17 Maximum service temperature The maximum temperature to which a cylinder may be subjected in normal service, to be taken as 65o C. 2.18 Mobile gas storage A gas cylinder system or tank system permanently mounted on a dedicated carriage or vehicle, used for the transportation of CNG to daughter refuelling stations. 2.19 Mobile compressor A compressor which is permanently mounted on a dedicated carriage or vehicle, used for the re- compression of CNG at daughter refuelling stations.

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2.20 Mother refuelling station An installation whose primary function is the compression and transfer of gas into mobile gas storage. Mother stations may also dispense CNG to vehicles on site. 2.21 MSC Metric Standard Conditions, i.e. at standard temperature (15o C) and standard pressure (101.325 kPa absolute). 2.22 Natural gas A hydrocarbon fuel gas consisting predominantly of methane. 2.23 Pressure relief device A device which prevents a predetermined pressure being exceeded in the equipment being protected. 2.24 Protected works Any of the following:

(a) Any building in which persons are present; (b) Any factory or workplace, except a building dedicated to the

storage and handling of CNG; (c) A storage or handling area of combustible or flammable

materials. 2.25 Public place A place, other than private property, open to the public and including public roads. 2.26 Public refuelling station A refuelling station which provides public access to all refuelling vehicles. 2.27 Non-public refuelling station A refuelling station, usually located within a private property, which does not service vehicles other than those of a particular fleet or fleets. 2.28 Refuelling connection, refuelling connector (nozzle) Equipment fitted at the free end of the refuelling hose to enable the transfer (dispensing) of CNG from the refuelling station into the CNG vehicle. 2.29 Refuelling hose isolating valve A manual quarter-turn valve mounted on the dispenser for the purpose of quick isolation of the refuelling hose from the upstream system.

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2.30 Refuelling hose valve A valve, located in the refuelling hose just upstream of the refuelling nozzle, to control the flow of gas to the refuelling vehicle and to depressurise the section between it and the refuelling connection. 2.31 Refuelling hose valve vent line The gas line which conducts the vented gas from the refuelling hose valve to a safe place. 2.32 Site operator The company responsible for the operation and management of the refuelling station. 2.33 Standing rules for work on site Basic rules to be observed at all times of work on-site to ensure that the safety of staff and equipment is maintained. 2.34 Temperature-compensated refuelling pressure Refuelling pressure which is automatically adjusted to take into account the temperature variations in the vehicle cylinders during refuelling.

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3 Component requirements 3.1 General 3.1.1 All components in contact with natural gas shall be compatible with natural gas and shall be rated for the maximum pressures, temperatures and loading to which they may be subjected. 3.1.2 All other components shall be suited to the requirements of the intended service, which include local ambient and operating conditions. 3.2 Compressors 3.2.1 Compressors shall be capable of operating consistently and durably with the inlet gas of the composition specified by the gas supplier. 3.2.2 Compressors shall meet the requirements specified in Annex C. 3.2.3 Natural gas shall be delivered to the compressors with the required level of odorant as specified by the relevant regulatory authority.

3.2.4 Where required, the compressors shall be fitted with treatment equipment to ensure that no liquid water will form anywhere in the refuelling station system and the CNG vehicle systems in normal operation. NOTE: ISO 15403 gives the method of determining whether liquid water will form at different temperatures and pressures of CNG fuel, for a given inlet gas water content. 3.2.5 Adequate oil removal equipment shall be fitted to minimise oil carryover at the compressor outlet. NOTES: 1. The designer should take into account that at the relatively high compressor outlet temperature, oil is

carried in the gas stream as both droplets and in the gas phase.

2. A recommended maximum level of total (droplets and vapour phase) carried over oil at the compressor outlet is 30 mg/m3.

3.3 Gas storage containers 3.3.1 Gas storage containers shall be either gas cylinders or bulk tanks. 3.3.2 Container materials which can deteriorate under ambient or operating conditions shall be suitably protected by painting or equivalent means. 3.2.3 Containers exposed to direct solar radiation shall have an external finish in white or silver grey. 3.4 Valves and piping 3.4.1 Valves The manufacturer shall stamp or otherwise permanently mark the valve body to indicate the manufacturer’s name or trademark and pressure rating.

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3.4.2 Master shut-off valve and refuelling hose isolating valve 3.4.2.1 The master shut-off valve (see Clause 4.1.4.2) and refuelling hose isolating valve (see Clause 4.1.4.4) shall be clearly labelled, with red letters of not less than 20 mm height on a white background. The valves or valve labels shall clearly indicate the direction of closing. 3.4.2.2 The valve labels shall be located as close to the valves as practicable. 3.4.3 Rigid piping 3.4.3.1 All rigid pipe, tube, fittings and other piping components shall be designed with a factor of safety of at least four based on the minimum specified tensile strength at 20oC. 3.4.3.2 Pipes made of materials that can deteriorate under ambient or operating conditions shall be suitably protected from such occurrence. 3.4.3.3 Rigid metallic fuel lines subjected to full cylinder/tank pressure shall be one of the following types: (a) Seamless steel tubing complying with ASTM A 269; (b) Seamless steel tubing complying with ASTM A 53; (c) Other approved types. 3.4.4 Pipe joints and connections Joints and connections for piping which is subjected to full cylinder/tank pressure shall be one of the following types: (a) Screwed joints, provided that when the thread is used as a dry seal, only taper-to-taper

threads shall be used; (b) Ground faced unions in accordance with SAE J1453; (c) Other approved fittings including proprietary two-ferrule compression fittings. 3.4.5 Hose assemblies All flexible hose assemblies shall meet the requirements of ISO 15500-17. 3.5 Overpressure protection

3.5.1 General 3.5.1.1 Each overpressure protection device shall be clearly marked by its manufacturer or agent with the pressure at which it is set to activate. 3.5.1.2 The rated discharge capacity of the overpressure protection device shall be greater than the flow rate into the component being protected. 3.5.2 Pressure relief devices 3.5.2.1 Pressure relief devices shall not be fitted with lifting devices. Adjustments shall be provided with a means for sealing to prevent unauthorised tampering. 3.5.2.2 Gas cylinders and storage tanks shall be fitted with pressure relief devices specified by the cylinder or tank manufacturer, and set at activation pressures specified by the relevant cylinder/tank standard.

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3.6 Pressure gauges 3.6.1 Pressure gauges shall comply with standard BS EN 837 or equivalent and shall have a dial graduated to read no less than 1.2 times and no more than 2 times the operating pressure. 3.6.2 Pressure gauges used on gas storage vessels shall comply with BS EN 837 or equivalent standards and shall have a dial graduated to read no less than 1.2 times and no more than 2 times the maximum developed pressure. 3.6.3 Pressure gauges for operating pressures greater than 2.5 MPa shall have special safety provisions of BS EN 837. 3.7 Electrical equipment and wiring 3.7.1 All electrical wiring and equipment shall be in accordance with SS CP 5 and the requirements of the electricity supply authority. 3.7.2 Electrical equipment shall be suitable for the specific area as defined in AS/NZS 2430.3 or an approved equivalent national standard. 3.7.3 All conductive surfaces (e.g. framework, piping, etc.) shall be adequately bonded to a common earth. 3.8 Dispensers 3.8.1 The dispenser shall consist of a minimum of a refuelling hose(s), a refuelling hose valve(s), a pressure gauge to indicate the refuelling hose pressure, a hose safety breakaway coupling(s) and refuelling hose isolating valve. 3.8.2 Refuelling hose electrical conductivity To minimise the risk of ignition sparks from electrostatic charge build-up or accidental contact with live parts of the refuelling vehicle’s electrical system, some electrical conductivity shall be provided to the refuelling hose system. The resistance from any part of the refuelling hose assembly, including valve handles and handgrips, to the dispenser body or to the refuelling nozzle shall be between 1 k��DQG����M�� ZKHQ� PHDVXUHG� ZLWK� DQ� DSSOLHG� SRWHQWLDO� RI� QRW� JUHDWHU� WKDQ� ���� YROWV� G�F��� ZKHQ� PHDVXUHG�according to BS 2050 or an equivalent standard. 3.8.3 Refuelling hose safety breakaway coupling 3.8.3.1 The refuelling hose assembly shall incorporate a breakaway hose coupling designed to provide safe disconnection in the event of undue force being applied to the hose, such as a vehicle moving away while still connected to the hose. 3.8.3.2 The coupling shall be designed in accordance with the following requirements: (a) The axial force required to separate the coupling shall be:

(i) less than 600 N for hoses of nominal diameter below 12.5 mm (ii) less than 800 N for hosed of nominal diameter above 12.5 mm

(b) The coupling shall retain gas within both sections of the hose after separation. (c) The coupling shall be located to ensure that the breakaway force is applied axially. The coupling should be capable of being reassembled after separation, preferably without the use of special tools or the replacement of parts. 3.8.3.3 The refuelling hose valve (see Clause 3.8.5) vent line, if connected to a point beyond the dispenser, shall also incorporate its own breakaway coupling. This coupling shall be designed so that the axial force required to separate shall be less than 100 N.

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3.8.3.4 If the vent line is connected back to the compressor system a non-return valve shall be fitted to prevent a backflow toward the refuelling connector. 3.8.3.5 The dispenser shall be capable of withstanding twice the force necessary to separate the breakaway hose coupling without damage or deformation. 3.8.4 Refuelling connector 3.8.4.1 The refuelling connector shall meet the requirements of ANSI/AGA NGV 1, for 3000 psi service pressure. The female component (the nozzle) of the connector shall be attached to the refuelling hose. 3.8.4.2 Other approved refuelling connectors may be used by refuelling stations which service a

specific vehicle fleet using those connectors. 3.8.4.3 The use of adapters on refuelling nozzles shall be prohibited.

3.8.5 Refuelling hose valve A valve shall be installed in each refuelling hose assembly to control the refuelling of vehicles. This valve shall have a means of depressurising the refuelling connection to allow disconnection. NOTE: The refuelling hose valve and its depressurisation means may be incorporated into the refuelling nozzle. 3.8.6 Refuelling pressure control 3.8.6.1 For both fast and slow fill systems, the refuelling pressure control system shall limit the vehicle refuelling pressure in accordance with the maximum fill pressure specified by ISO 11439, i.e. 20 MPa at 15o C. 3.8.6.2 For fast fill systems with temperature-compensated pressure control, the maximum allowable refuelling pressure limit shall be 26 MPa. 3.8.6.3 For fast fill systems without a temperature-compensated pressure control system, the maximum fill pressure shall be 20 MPa. For non-public and special purpose refuelling stations which service vehicles with CNG cylinders made to standards other than ISO 111439, CSA B51 Part 2 or ANSI/IAS NGV 2: (a) the refuelling pressure shall comply with the limits specified by the vehicle fuel cylinder

standard; (b) the refuelling nozzle shall be of an approved type, if it differs from that specified in Clause

3.8.4.1. 3.8.7 Dispensers with CNG flow meters 3.8.7.1 Where CNG flow meters are fitted for the purpose of commercial fuel transactions, the entire dispenser including the CNG flow meters shall be approved by the relevant regulatory authority. 3.8.7.2 The CNG flow meter/dispenser system shall meet the accuracy requirements at type approval time and at periodic recertification as specified by the relevant regulatory authority.

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4 Installation of equipment 4.1 Location of major equipment 4.1.1 CNG gas storage units 4.1.1.1 CNG gas storage units located outdoors shall be placed at distances specified in Table 4.1. 4.1.1.2 CNG gas storage units located outdoors and contained within weatherproof enclosures shall be regarded as not being indoors. Table 4.1 Separation distances from CNG gas storage units

Minimum distance from a fixed source of ignition (see Note 2)

Total capacity of CNG gas storage units (m3) Lateral

(m) Above (m)

Minimum distance from protected works, public place, property boundary and above ground flammable liquid tank (see Note 2) (m)

Up to 30

0 0 0

>30 to 90

1.5 1.5 1

>90 to 600

3 3 2

>600 to 2500

4

>2500 to 10 000

8

>10 000

5 3

as approved by the relevant regulatory authority

NOTES: 1. For the purposes of refuelling, a motor vehicle entering a hazardous zone is not considered as a

source of ignition. 2. The separation distances may be reduced where a 240/240/240 FRL concrete or masonry wall is

provided in accordance with ISO 834. The wall shall be a minimum height of 0.4 m above the top of the storage units and be of a length to achieve the “tightwire” distances in Table 4.1.

4.1.2 Compressors 4.1.2.1 Compressors should preferably be located outdoors. 4.1.2.2 Compressors which are located outdoors within weatherproof enclosures shall be regarded as not being indoors. 4.1.2.3 If located indoors (also see Clause 6.4), ventilation shall be adequate to meet the cooling requirements of the compressor. 4.1.2.4 Unless otherwise specified by the manufacturer a minimum clearance of 1 m shall be provided around compressors for maintenance purposes. NOTE: An access door for maintenance access may reduce this clearance requirement.

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4.1.3 Fuel dispensers Fuel dispensers shall be located outdoors and the zone around them shall meet the following requirements: (a) No part of a vehicle being refuelled shall be in a public place; (b) The dispensing zone, being the area swept by the end of the refuelling hose, shall not encroach

on a public place or protected works; (c) Separation distances shall be not less than those given in Table 4.2. Table 4.2 Separation distances from dispensers

Distance (m) From dispenser body From edge of dispensing

zone (see Clause 4.1.3(b)) Public place Protected works: • Buildings

• Combustible material storage

• Other fuel dispensers

• Above ground flammable liquid

tank Fixed ignition source (see Note 1) CNG gas storage Openings in buildings

1 1 3 1 3 3 0 3

0 0 3 (see Note 3) 0 0 3 0 2 (see Note 3)

NOTES: 1. For the purposes of refuelling, a motor vehicle entering a hazardous zone is not considered as a source of

ignition. 2. The separation distances may be reduced where a 240/240/240 FRL concrete or masonry wall

is provided in accordance with ISO 834. The wall shall be a minimum height of 0.4 m above the top of the dispenser and of a length to achieve the “tightwire” distances in Table 4.2.

3. The distance from the dispensing zone may be reduced to 1 m if the refuelling hose valve vent is piped away to a safe location.

4.1.4 Essential manual operational valves 4.1.4.1 Storage unit isolating valve - An isolating valve of the quarter-turn type shall be installed in the outlet pipe of each storage unit. This valve shall be within the security fence enclosure (see Clause 4.7.1). 4.1.4.2 Master shut-off valve - If the storage unit is located within an enclosure, a master shut-off valve shall be installed in each pipe outside the enclosure but immediately adjacent to the storage system. This valve shall be of the quarter-turn type. 4.1.4.3 In refuelling stations where there is no enclosure surrounding the storage unit, or when refuelling is carried out immediately adjacent to the storage unit, the storage unit isolating valve may act as the master shut-off valve. For a multipipe system, i.e. one where there are more than one pipe from the storage unit to the dispenser(s), these valves shall be installed adjacent to one another.

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4.1.4.4 Refuelling hose isolating valve - A quarter-turn valve shall be installed in the dispenser outlet pipe in a position readily accessible to the vehicle refueller.

NOTE: Annex E gives a typical arrangement of essential manual operational valves. 4.2 Installation of compressors 4.2.1 Compressor foundations Compressor foundations shall be in accordance with the manufacturer’s recommendation. The design shall take into account vibration, dynamic balance, damping characteristics and all relevant loads under normal operating conditions. 4.2.2 Inlet gas equipment The following shall be provided on the inlet gas line to a compressor: (a) An isolating valve; (b) A non-return valve which shall have a minimum pressure rating equal to that of the first stage

relief valve setting. This valve shall be fitted upstream of the flexible connection; (c) A flexible connection; (d) A pulsation damper as required by the relevant gas supply authority; and (e) A filter as specified by the compressor manufacturer. 4.2.3 Outlet gas equipment The following shall be provided on the outlet line: (a) A flexible connection to prevent mechanical vibration being transmitted to the fixed gas outlet

equipment; and (b) A non-return valve which shall be fitted downstream of the flexible connection and upstream

of any storage unit. 4.2.4 Noise levels The compressor and its enclosure, if fitted, shall emit sound levels which do not exceed the legally allowable noise level at the property boundaries of the refuelling station. 4.3 Installation of CNG storage system 4.3.1 CNG storage shall be installed on an appropriately design foundation. 4.3.2 Multiple cylinder storage units which have cylinders stored in a vertical position shall be limited to a width of 1.1 m and a height of 1.6 m above the floor level unless access arrangements are provided not more than 1.6 m below the cylinder valves. 4.3.3 Multiple cylinder storage units which have cylinders stored in a horizontal position shall be limited to a height of 2 m unless access arrangements are provided for safe and effective operations and maintenance. 4.3.4 The cylinders shall be separated from one another using a material that does not entrap moisture. Special precaution shall be taken at the points of contact to avoid corrosion. 4.3.5 To ensure ready access, all cylinder valves shall be arranged on one end of each unit. NOTE: When cylinders are stored in direct sunlight, consideration may be given to a shield to prevent pressure build-up induced by solar heating.

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4.3.6 Storage units may be grouped up to an aggregate volume of 4000 m3. Storage units should be separated from one another by a minimum distance of not less than the protected works distance for the largest group (Refer to Table 4.1). 4.3.7 Every storage unit shall be fitted with its own pressure gauge. 4.3.8 Storage units shall be installed on a firm, compacted, well-drained foundation. 4.3.9 Storage units may be protected by a roof or housed in an enclosure designed to facilitate the dispersion of gas in the event of a leak. NOTE: Isolation distances and equipment layout of gas storage units at a typical refuelling station are shown in Annex D. 4.4 Installation of piping 4.4.1 General 4.4.1.1 Flexible piping shall only be used: (a) in connections to and from the compressor and any inter-stage pipework. The flexible piping

shall be kept to a minimum sufficient for the purpose of vibration elimination; (b) downstream of the refuelling hose isolation valve; and (c) for the transfer of CNG to and from mobile gas storage. 4.4.1.2 Flexible piping installation shall be take into consideration the prevention of mechanical damage due to movements during operation as a result of changes in gas pressure. 4.4.1.3 All piping and tubing shall be run as directly as practicable with adequate provision for expansion, contraction, jarring, vibration and settling. 4.4.1.4 The number of joints in a pipeline shall be kept to a minimum. 4.4.1.5 All welded piping shall be fabricated and tested in accordance with BS 806 or equivalent standards. 4.4.1.6 All welding in high pressure pipelines throughout the storage and compressor system shall be carried out by a certified welder.

4.4.2 Above-ground piping All piping shall be adequately supported and protected against mechanical and corrosive damage. Where overhead piping crosses the vehicle access way it shall be at least 4.5 m above the road surface or as determined by the relevant regulatory authority. 4.4.3 Underground piping 4.4.3.1 All piping shall be coated and cathodically protected in accordance with the requirements of AS 2832.1 or equivalent standards. 4.4.3.2 The minimum buried depth for underground piping shall be 800 mm subject to local conditions and traffic patterns. 4.4.3.3 As-built drawings containing underground pipeline location details shall be provided to the station operator.

4.4.4 Provisions for system depressurisation

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4.4.4.1 Means shall be provided in piping systems downstream of the compressor to permit the safe depressurisation of NGV pipelines before servicing. 4.4.4.2 Normal pipework connections such as flanges and pipe fittings shall not be used for system depressurisation. 4.4.4.3 An approved sealant shall be used on all pipe joints. 4.5 Installation of dispensers 4.5.1 Dispensers shall be installed on a firm, compacted, well-drained foundation. 4.5.2 The vehicle refuelling hose shall be adequately supported to prevent kinking and the hose assembly shall facilitate easy withdrawal after completion of refuelling. 4.5.3 The hose assembly shall not come into contact with the ground during normal use. This may be achieved by using an overhead hose assembly supported from the dispenser. 4.5.4 Gas vented from the refuelling hose valve at the completion of refuelling shall be piped away to a safe location (also see Clause 3.8.3.3). 4.6 Installation of overpressure protection 4.6.1 All pressure relief device vents shall be oriented such that gas discharge will directed away from gas storage cylinders/tanks, other equipment or structures, and service personnel working in the immediate area. 4.6.2 All pressure relief devices, other than burst discs or those integral with the service valves on gas storage cylinders/tanks, shall be fitted with suitable covers to prevent the ingress of water, dirt or other extraneous materials. 4.6.3 The discharge piping system shall comply with the requirements of Clause 6.1.3. 4.7 Security and damage protection 4.7.1 Security 4.7.1.1 Compressors and gas storage units shall be protected against unauthorised entry by use of : (a) A specific equipment enclosure with lockable access panels which are of sufficient size to

give complete access to the equipment; or (b) A rugged steel mesh fence or equivalent protection with a nominal height of 1.8 m and at a

minimum distance of 1 m from the equipment. 4.7.1.2 For non-public refuelling stations, the requirement of Clause 4.7.1.1 may be met by an existing enclosure, or a fence that secures the whole property site. 4.7.1.3 For public refuelling stations, the measures of Clause 4.7.1.1 shall isolate the equipment from the rest of the site. 4.7.2 Damage protection 4.7.2.1 A dispenser shall be protected from vehicle impact by its location, or by external guard rails or bollards. NOTE: When selecting the distance between the guards and the dispenser, consideration should be given to dispenser accessibility to allow ease of operation. 4.7.2.2 Any other gas equipment, which because of its location, is susceptible to damage from manoeuvring vehicles shall be protected against impact by such vehicles.

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NOTE: The following are examples which are considered to provide adequate damage protection. Other arrangements may be used to provide equivalent protection. (a) 75 mm diameter steel pipes filled with concrete, spaced at a maximum of 1.2 m apart and at least 1.2

m high. They shall be at least 1.5 m from the gas equipment. (b) Highway crash barrier (e.g. steel railing) at least 700 mm high and 1.5 m from the equipment being

protected. (c) A combination of 1.8 m high rugged steel mesh fence, or equivalent protection, at least 1 m from the

equipment, together with a raised kerb, at least 200 mm high and at least 2 m from the equipment (see Annex D).

4.8 Emergency shut-down 4.8.1 For emergency situations, a readily accessible manually reset push button shall be mounted on each of: (a) the exterior of the compressor enclosure; and (b) the fuel dispensers. 4.8.2 The operation of the emergency push buttons shall completely shut down the entire CNG refuelling station and shall isolate all incoming gas supply to the compressors and from the CNG gas storage units to the dispensers. 4.8.3 The emergency push buttons shall be clearly marked with signs in accordance with Clause 6.2.1. 4.9 Site lighting Installations where fuel dispensing will take place at night on a regular basis shall be equipped with fixed lighting capable of providing illumination at a level of not less than 50 lux within the dispensing area. 4.10 Risk assessment of total installation It shall be demonstrated, by an accepted risk assessment methodology, that the entire installation will in operation: (a) not impose unacceptable risks of injury or fatality to operating personnel, customers and

persons in public areas and adjacent properties; and (b) not impose unacceptable risks of material damage to structures and materials within the site

as well as in adjacent properties. The risk assessment shall be conducted by competent person(s) with adequate knowledge of CNG refuelling system components and systems and their operational characteristics. The risk assessment shall take into account: (a) the equipment/components used, including compressors, pipework, pipe fittings, gas storage

systems, valves and pressure relief systems; (b) the equipment arrangement and plant layout; (c) the surrounding land use; and (d) the site geometry and topography. The design of the entire CNG refuelling station shall ensure that the calculated risks fall within limits accepted by the relevant regulatory authority. Operating measures recommended by the risk assessment shall be incorporated into the Safety Management System (see Clause 6.5).

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5 Mother – daughter refuelling stations 5.1 Mother-daughter refuelling station configurations 5.1.1 The mother station may service only mobile gas storage units, or it may also supply CNG to its own on-site vehicle refuelling dispensers. 5.1.2 The daughter station may dispense gas directly from the mobile storage, or it may use on-site compressors to recompress gas from the mobile gas storage to on-site CNG gas storage. 5.1.3 The mobile gas storage may also incorporate an on-board gas compressor for the same purpose as the on-site daughter station compressor of Clause 5.1.2. 5.1.4 In all cases the total full mass (including gas) of the vehicle on which mobile CNG station equipment is transported shall not cause the legal axle load limits to be exceeded by the vehicle on which the equipment is mounted. 5.1.5 Each vehicle performing the function of the mobile CNG fuel storage, compression or refuelling station shall have the gas equipment installed and operated/maintained in accordance with TR 10 and TR 11. 5.1.6 Each vehicle performing the function of the mobile CNG fuel storage, compression or refuelling station shall be equipped with at least two fire extinguishers of dry powder type having a rating of 21A/70B in accordance with SS 232 -1 and a capacity of at least 9 kg. The extinguishers shall be securely mounted, using attachments with strength complying with Table 5.1, in a readily and externally accessible position on either side of the vehicle. 5.2 Mobile gas storage 5.2.1 Gas cylinder/tank mounting attachments 5.2.1.1 The mobile gas storage shall be attached to the vehicle such that the force necessary to separate the cylinders/tanks from the vehicle in any direction shall be not less than the mass of the full cylinders/tanks times the design factor shown in Table 5.1. 5.2.1.2 The strength of the attachments may be established by dynamic test (deceleration over 20 milliseconds), static test (with forces directed through the centre of mass of the gas storage units and the individual cylinder/tanks), or by calculations by a competent designer. 5.2.1.3 The design of the cylinder/tank attachments shall in addition take into account fatigue factors resulting from vehicle operation. 5.2.1.4 The mounting method shall not significantly weaken the vehicle structure. 5.2.1.5 Supports shall not be welded to gas cylinders. Supports and other attachments may be welded to pressure vessels only during manufacture and prior to post-weld heat treatment and testing of the pressure vessels. Table 5.1 Mobile gas storage attachment design factor

Acceleration direction Design factor Longitudinal 10 g Lateral 5 g Vertical 4.5 g NOTE: “g” is the gravitational acceleration. “Longitudinal”, “lateral” and “vertical” refer to the directions of the principal axes of the vehicle on which the CNG equipment is mounted.

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5.2.2 System protection 5.2.2.1 All components of the mobile gas storage system shall be mounted within the perimeter of the vehicle body as determined by the vehicle manufacturer. 5.2.2.2 The cylinders/tanks shall not be in contact with any part of the vehicle, any piping, or any objects which could cause rubbing or the entrapment of moisture. 5.2.2.3 The cylinders/tanks together with their associated attachments shall be located and protected so that the possibility of damage from impact, accident, or loose objects is minimised. 5.2.2.4 The cylinder/tank manufacturer’s instructions regarding exposure to sun, water or chemicals (e.g. battery acids) shall be considered in the design of the mobile gas storage unit. 5.2.2.5 Engine exhaust outlets shall be directed away from the mobile gas storage cylinders/tanks. 5.2.3 Pressure relief devices Pressure relief devices fitted on the gas storage unit shall have their discharges directed vertically upward. 5.2.4 CNG storage system information plate The following information shall appear on a durable plate which shall be installed near the storage unit filling connection location: (a) “CNG fuel storage unit”; (b) The rated working pressure, in MPa; (c) The cylinder identification numbers and the stamped date of the next periodic recertification.

When a cylinder(s) is changed, this information shall be accordingly updated. 5.2.5 Signs and notices Clear, concise and durable signs in accordance with SS 217 in letters at least 50 mm high shall be affixed to the mobile gas storage unit in a highly visible location stating: (a) the product being carried is compressed natural gas; (b) the dangerous goods classification of the gas; (c) “NO SMOKING”, “NO NAKED FLAMES” and “NO ELECTRICAL APPLIANCES” in red letters

on a white background; (d) “EMERGENCY SHUT-OFF VALVE(s)” (at the valve location), in red letters on a white

background, together with an arrow indicating the closing direction; (e) The owner/operator’s emergency contact numbers; and (f) The fire brigade phone number. 5.3 Mobile compressors 5.3.1 All requirements of the static station compressors, specified in all other Sections of this Technical Reference, shall be met by compressors mounted on vehicles when they are in operation. 5.3.2 Vehicle mounting attachments for the compressors shall have strength meeting the design factors of Table 5.1. 5.3.3 Where mobile compressors are not mounted on the same vehicle as the mobile gas storage, the signs and notices of Clause 5.2.5, with the exception of item (d), are to be used on mobile compressors.

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5.4 On-site location of compressors and gas storage 5.4.1 The location of on-site static compressors and static CNG gas storage units at mother and daughter stations shall comply with the requirements of Clause 4.1. 5.4.2 For mobile storage units, in addition to the separation distance requirements of Clause 4.1, a parking bay shall be provided at both the mother station and mother station. The parking bay shall have a firm, compacted, well-drained foundation. 5.4.3 Where a security fence is not provided at the property boundary of the mother and daughter stations, the mobile CNG gas storage unit parking area shall be provided with its own security fence, with a minimum width of 5 m, a minimum clearance of 1 m all round the mobile storage unit, and access gates provided at both ends. The gates shall open only outward. 5.5 On-site notices Clear, legible, concise and durable operating instructions shall be posted in an obvious position adjacent to any area where CNG is being loaded onto or unloaded from CNG mobile storage units. 5.6 Risk assessment of installations All mother and daughter installations, including mobile facilities, shall be assessed to have acceptable risks as specified in Clause 4.10. 6 System installation – Safety provisions 6.1 Safety devices for overpressure protection 6.1.1 Refuelling overpressure protection 6.1.1.1 A pressure relief valve shall be fitted on the dispenser delivery line downstream of the refuelling hose isolating valve. 6.1.1.2 The pressure relief valve shall be designed to prevent the pressure in the dispensing line from exceeding 110% of the refuelling pressure limit specified in Clause 3.8.6. 6.1.2 Static gas storage overpressure protection 6.1.2.1 Each storage unit shall be equipped with a means for preventing it from being filled to a pressure higher than that for which it is designed. The selection of the device shall be in accordance with the standard to which the storage cylinders/tanks are made, or as approved by the relevant regulatory authority. NOTE: The final stage relief valve of the compressor may be considered as serving this purpose. 6.1.2.2 All pressure relief devices, other than burst discs or those integral with service valves on bulk tanks or cylinders, shall be fitted with suitable covers to prevent the accumulation of water, dirt or extraneous material. 6.1.3 Pressure relief discharge piping Any discharge piping of overpressure protection devices shall comply with the following requirements when installed: (a) It shall be designed for the pressure of, and the forces generated by, the discharged gas; (b) It shall be adequately sized to ensure the required relief flow rate is achieved; (c) Its direction shall not permit escaping gas to impinge on any piping or structure;

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(d) Venting shall be to a safe place direct to atmosphere (except for the presence of the protective cover); and

(e) Its outlet shall not be vulnerable to physical damage. 6.2 Signs and notices

6.2.1 Signs The following durable signs in bright red letters on a white background, in accordance with SS 217, shall be installed: (a) NO SMOKING, FLAMMABLE GAS and NO NAKED FLAMES adjacent to the compressor

and gas storage area and located in a position obvious to anyone approaching the area. Letters shall be at least 50 mm high.

(b) Where compressors are subjected to automatic starting: CAUTION: THIS MACHINE MAY START AUTOMATICALLY AT ANY TIME, to be located in an obvious position and of letters of at least 30 mm high. (c) STOP ENGINE, NO SMOKING, FLAMMABLE GAS, NO NAKED FLAMES and NO

ELECTRICAL APPLIANCES, adjacent to dispensers and in letters at least 50 mm high. (d) EMERGENCY SHUT-DOWN adjacent to the emergency shut-down push buttons (see

Clause 4.8) in letters at least 30 mm high. 6.2.2 Notices Clear, legible, concise and durable operating instructions shall be posted in an obvious position adjacent to any area where CNG dispensing takes place. 6.3 Fire protection 6.3.1 There shall be at least one fire extinguisher of dry powder type with a rating of at least 21A/70 B, as rated in accordance with SS 232 -1 and a capacity of at least 9 kg. This extinguisher shall be located within 4 m of the gas compressor and gas storage area and a fire extinguisher shall be provided within ready access of the dispensing area. NOTE: One extinguisher may in some cases satisfy both requirements. 6.3.2 For aggregate gas storage greater than 600 m3 (MSC) a fire hose reel shall be provided in addition to the requirements of Clause 6.3.1. 6.3.3 The fire hose reel shall comply with CP 29. 6.3.4 The hose reel shall be located such that the nozzle end of a fully extended fire hose, fitted to the reel and laid to avoid any partitions or other physical barriers, shall reach every part of the storage. Where this cannot be achieved within the maximum hose length of 30 m, additional hose reels shall be provided. 6.3.5 The fire hose reel(s) shall be fitted with nozzles which can provide a fog spray. 6.4 Indoor installation 6.4.1 Fuel dispensers shall not be located indoors. 6.4.2 CNG refuelling station equipment housed in closed underground installations shall be

considered as indoor.

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6.4.3 Compression and gas storage equipment if located indoors shall comply with the following requirements. 6.4.3.1 Explosion venting shall be provided in exterior walls or roof only. . NOTE: NFPA 68 gives information on the venting of explosions. 6.4.3.2 The room containing CNG equipment shall be sealed from other parts of the building and have walls and roof constructed of non-combustible materials with a fire resistance level (FRL) of at least 120/120/120 as measured in accordance with ISO 834. At least one wall shall be an exterior wall. Windows and doors shall be located to be readily accessible in case of emergency. Access to the room shall be from outside the primary structure. 6.4.3.3 The CNG equipment room shall be equipped with a ventilation system arranged to provide uniform air movement to the extent practicable with inlets near floor level and outlets at the high point of the room in exterior walls or the roof: (a) Continuously operating mechanical ventilation shall be provided, interlocked with a

continuously operating gas detection system. The system shall shut down the CNG installation in the event of failure of the ventilation system or when the gas/air concentration reaches 20% of the gas’s lower flammability limit. The system shall sound an alarm and visually indicate, in the relevant staffed working areas, when this limit is reached.

(b) The ventilation rate shall be a minimum of five air changes per hour. (c) The ventilation system for the CNG installation shall be separate from any other ventilation

systems for the building. 6.4.4 For the purposes of selection of electrical equipment, the entire indoor compressor and/or storage area shall be considered equivalent to a compressor inside an enclosure. 6.4.5 Pressure relief device discharges from all gas containing systems shall be piped to the outside of the building and meet the requirements of Clauses 4.6 and 6.1.3. 6.4.6 Access doors shall have warning signs on the outside with the words “WARNING – FLAMMABLE GAS – NO SMOKING”, in legible, bright red letters on a white background with letters not less than 30 mm high. 6.5 Safety management 6.5.1 Safety management system A safety management system shall be established incorporating the following elements: (a) The site safety management policy; (b) The emergency procedures; (c) Staff response training; and (d) Documentation of (a), (b) and (c) to be retained on site by the station operator. 6.5.2 Emergency procedures 6.5.2.1 The emergency procedures shall cover action to be taken in the event of fire, gas leakage, accident, equipment failure or other abnormal occurrences. 6.5.2.2 The emergency procedures shall contain at least the following, as appropriate to the particular installation: (a) List of contacts, emergency services and their phone numbers; (b) Chain of command; (c) Duty list;

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(d) Co-operation with relevant authorities; (e) On-site staff response; (f) Debriefing and reporting; (g) Contractors; and (h) Site plan 5.5.3 Safety management training material Safety management training material shall contain basic but adequate information on the functions of all major components of the system, in particular with respect to how they affect the safety of the site. The training procedures shall cover all aspects of station operation and emergencies. 7 System commissioning 7.1 General 7.1.1 The system commissioning procedures shall comply with the requirements of, and approved by, all relevant regulatory authorities. 7.1.2 Performance tests are required to verify that the supplied equipment meets all requirements of the purchase and supply specification. 7.2 Installation approvals 7.2.1 The electricity supply authority is responsible for approving the electrical equipment, wiring and operation. 7.2.2 The local gas supply authority is responsible for approving the inlet gas connection, gas equipment and piping installation. 7.2.3 In considering the approvals, the authorities shall be satisfied that the operation of the facility will not adversely affect gas and electricity supply equipment upstream of the facility. 7.2.4 Other relevant authorities are responsible for approvals of other aspects, e.g. land use, noise and pollution. 7.2.5 Such approvals shall be obtained before the commissioning phase is considered to be completed. 7.3 Compressors 7.3.1 The compressors shall be verified to have been installed in accordance with the requirements of this Technical Reference. 7.3.2 The commissioning of compressors shall be carried out in accordance with the procedures produced by the manufacturer. 7.3.3 At first start-up of the compressors it is essential for commissioning personnel to ensure that all conditions of the manufacturer’s warranty have been observed and met. 7.3.4 The compressors shall be confirmed to be completely leak-free. 7.3.5 If specified by the purchase or supply specification, verification carried out for the compressor capacity and the maximum discharge gas pressure and temperature shall use methods accepted by the compressor purchaser.

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7.4 Piping 7.4.1 All piping shall be verified to have been installed in accordance with this Technical Reference. 7.4.2 Rigid piping 7.4.2.1 All piping and tubing shall be tested after assembly to a pressure equal to that of the associated safety device setting and shall be free of leaks. NOTE: It is recommended that this test be carried out using liquid (e.g. kerosene) or an inert gas. 7.4.2.2 Safety precautions appropriate to the pressurising medium used shall be rigidly applied.

7.4.3 Flexible piping Hose assemblies shall be hydrostatically tested, after assembly and prior to use, to at least twice the maximum operating pressure for a minimum of one minute. The hose assembly shall not leak, burst or suffer damage from pressurisation. 7.5 Electrical controls 7.5.1 All electrical equipment shall be of the approved type to meet the requirements of the classified hazardous areas. 7.5.2 All electrical functions shall be verified to be working as designed or intended in the expected operating mode. 7.5.3 All emergency shut-down alarms and sequences shall be verified as working. 7.6 Gas system controls 7.6.1 All gas systems shall be confirmed to have the correct pressure rating and, where applicable, the correct overpressure protection equipment fitted. 7.6.2 All gas system controls shall be verified to be working as designed or intended in the expected operating mode. 7.6.3 CNG dispenser flow meters, if fitted, shall be verified as having been approved by the relevant regulatory authority and as performing within the approved accuracy. 7.6.4 If required by the purchase or supply specification, the CNG compression, verification of the refuelling and dispensing system performance, e.g. refuelling speed and capacity, shall be carried out using agreed methods. 8 Refuelling station operation 8.1 Vehicle refuelling procedure 8.1.1 The station operator shall be trained to become totally conversant with the vehicle refuelling procedure and dispenser operating and safety characteristics. 8.1.2 The station operator shall ensure that all site staff involved in the CNG retail/dispensing activity are correctly trained and conversant with the safe vehicle refuelling operation and dispenser operating and safety characteristics.

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8.1.3 When required, the station operator or designated site staff shall assist vehicle operators in the correct refuelling procedure. NOTE: The refuelling procedure is given in Annex F. 8.2 Security of dispensers at public refuelling stations The dispensers at public refuelling stations shall be secured against unauthorised use when the station is unattended. 8.3 Security of mobile gas storage areas Where a security fence is provided around a mobile gas storage parking bay (see Clause 4.4.4), all gates shall be left open while the mobile gas storage is being moved or when there are personnel working within the bay. 8.4 Emergency procedure and drills 8.4.1 The station operator shall be trained to become totally conversant with the site safety management system (see Clause 6.5.1). 8.4.2 The station operator shall ensure that all site staff involved in the CNG retail/dispensing activity are correctly trained and conversant with the site safety management system. 8.4.3 All site staff involved in CNG retail/dispensing activity shall be given emergency drills at regular intervals . 8.5 Inspections and maintenance 8.5.1 Routine checks Routine checks shall be conducted to provide good housekeeping of the site. The interval of inspection shall be appropriate to the equipment under consideration. The routine checks may include: (a) clearing the site of unwanted extraneous material; (b) signs and notices are kept in a legible condition; (c) daily testing to confirm that emergency shut-down push buttons are in working order; (d) inspecting fire protection equipment; and (e) inspecting the general condition of pipes, hoses, cylinders, valves and pressure relief

devices. 8.5.2 Scheduled maintenance 8.5.2.1 Scheduled maintenance shall be conducted in accordance with the manufacturer’s specifications and instructions. NOTE: Where a scheduled maintenance event involves the replacement or re-setting of components, certain critical or important performance parameters , e.g. fast refuelling rate and dispenser metering accuracy, may need to be reconfirmed or reverified. 8.5.2.2 An annual inspection of the whole installation shall be carried out by suitably qualified personnel. The tasks include: (a) A leakage check of pipework and joints, and rectification of leaks found; (b) Visual inspection of all components. Substandard components shall be replaced.

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Particular attention shall be given to pressure regulators, safety devices and flexible piping.

8.5.3 A record of all inspections and maintenance shall be kept by the station operator and shall be available to the relevant regulatory authority on request.

8.6 Scheduled tests 8.6.1 Gas storage cylinders/tanks shall be periodically recertified by inspection and tests as specified by the cylinder/tank standard, or as directed by the relevant regulatory authority. 8.6.2 Safety devices other than burst discs and fusible plugs shall be inspected and tested at intervals not exceeding five years, to the requirements of the relevant regulatory authority. 8.6.3 Fusible plugs/burst discs shall be externally inspected at intervals not exceeding one year, for signs of damage or extrusion of the fusible material. 8.6.4 Refuelling hose assemblies shall be tested annually in accordance with Clause 7.4.3. 8.6.5 Refuelling hose safety breakaway couplings shall be tested annually by applying an axial force to ensure the coupling safely operates in accordance with the requirements of Clause 3.8.3.2. 8.6.5 A record of all inspections and tests shall be kept by the station operator and shall be available to the relevant authorities on request. 9 On-site work procedures 9.1 Work procedures It shall be the responsibility of the station operator to establish procedures appropriate to the installation. The procedures shall cover as a minimum: (a) Operating procedures, covering all aspects of the installation; (b) Routine checks as specified in Clause 8.5.1; (c) Scheduled maintenance as specified in Clause 8.5.2; (d) Scheduled tests as specified in Clause 8.6; (e) Emergency procedures, as specified in Clause 6.5.2; and (f) Training procedures, as specified in Clause 6.5.3. 9.2 Supervision All operating and maintenance work shall be planned and supervised by responsible and suitably qualified staff who shall ensure that all necessary safety precautions are observed. 9.3 Records All procedures specified in Clause 9.1 shall be fully documented and maintained by the station operator, with at least one copy of each being kept on site. The documents shall be reviewed at least every two years to include any changes occurring in the period leading to the review. Records shall be kept of: (a) Training and retraining of staff; and (b) Safety incidents and accidents, including “near-miss” events.

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9.4 Standing rules for work on site 9.4.1 Commissioning new or replacement equipment No part of the installation shall be put into operation until the following are available on site: (a) Operating and emergency procedures and associated equipment; and (b) Adequate personnel to cope with any possible fault condition. 9.4.2 Gas outlets not in use Any gas outlets which are not in use shall be capped or otherwise blanked off to prevent inadvertent release of gas, irrespective of the fitting of a valve. 9.4.3 Ignition sources No ignition sources shall be introduced into a hazardous area without authority. Welding, cutting and similar operations shall be conducted at all times only if authorised and in accordance with the provisions of an approved hot work permit system. 9.4.4 Illumination No work shall be carried out without adequate illumination. Portable lamps taken into hazardous areas shall be approved for the purpose. 9.4.5 Contract work Any contractor engaged to carry out work within any hazardous area shall be subject to the following conditions: (a) Methods and safety procedures appropriate to the work and the area; and (b) All work shall be planned and supervised by qualified responsible staff. All work shall comply with the requirements of work permit system applicable to the work site. 9.5 Maintenance, inspection and testing 9.5.1 Routine checks A routine check procedure shall be prepared for each installation appropriate to that installation. Such a procedure shall cover: (a) All operating valves, instruments and systems; (b) Emergency shut-down systems; (c) Safety valve protective caps and discharge provisions; (d) Fire protection equipment. A record of all tests and inspections shall be kept by the refuelling station operator. 9.5.2 Authorisation of work No work shall be allowed within hazardous areas without authorisation by the refuelling station operator and the gas and electricity supply authorities as appropriate in the form of: (a) A written procedure, in the case of standardised and repetitive normal activity; and (b) A work permit, in the case of potentially hazardous activities requiring close attention, e.g.

cutting, welding, grinding.

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Annex A List of regulatory authorities

(Informative)

National Environment Agency • Environmental pollution control; e.g. venting of CNG to atmosphere, disposal and recycling of

CNG cylinders.

Singapore Civil Defence Force and National Environment Agency • Risk assessment of CNG refuelling stations and CNG gas storage trailers. Singapore Civil Defence Force • CNG gas storage cylinder recertification inspection and testing. • Inspection and testing of safety devices other than cylinder safety relief devices (burst discs and

fusible plugs). • Off-site emergency plans. SPRING Singapore (Weights and Measures Office) � Pattern approval and periodic verification of CNG flow meters/dispenser systems.

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Annex B Requirements for compressors

(Normative) C.1 General C.1.1 All electrical wiring and equipment shall be in accordance with SS CP 5. C.1.2 Compressors and their associated equipment shall be manufactured in a manner that will facilitate operation, servicing and replacement of parts. C.1.3 Compressors intended for outdoor service shall have all parts suitably protected to ensure safe and reliable operation. C.1.4 Compressors shall be supplied with clear and readily accessible permanent markings which include: (a) Manufacturer’s name; (b) Model number; (c) Serial number and date of manufacture; (d) Rated capacity at designated inlet pressure; (e) Maximum and minimum allowable inlet pressure; (f) Maximum allowable outlet pressure; (g) Operating speed (rpm); and (h) Electrical markings as required. C.1.5 Compressors shall have an adequate gas cooling system, incorporating interstage, and discharge cooling if necessary, to give the lowest practicable gas outlet pressure. C.1.6 Compressors shall be supplied with installation, operating and servicing data and instructions. C.2 Operational equipment Compressors shall be fitted with the following operational equipment: C.2.1 Hour meter - A meter shall be fitted to record the total compressor operating time. C.2.2 Cut-out switches - The following switches shall be fitted: (a) Low inlet pressure; (b) High inlet pressure; (c) High outlet pressure; (d) Low oil pressure and/or low oil level; (e) High hydraulic oil temperature (if applicable); and (f) Low hydraulic oil level (if applicable) All of the switches above except (c) shall, after tripping, lock out the compressor. An outlet overpressure switch which will lock out the compressor should also be considered. C.2.3 The following shall be fitted: (a) High outlet temperature switch on the final stage; and (b) Indicators to indicate which fault has initiated the shut-down. C.3 Safety requirements The compressor shall be fitted with the following safety features:

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C.3.1 Condensate drainage system Provision shall be made for the removal and collection of liquid condensate from the discharge oil/gas separator. Gas escaping with the drained liquid shall be separated and piped to the supply line. C.3.2 Unloading system The unloaded gas shall be returned to the compressor inlet in such a manner that no part of the inlet system is overpressurised. The unloading system may be combined with the drainage system. C.3.3 Relief valves Each stage of compression shall be fitted with an approved spring-loaded relief valve sized for the compressor capacity. The set pressure shall be at least 15% above the operational discharge pressure of the associated stage but shall not exceed the design pressure, except that the final stage safety valve may be set at 10% above the maximum operational discharge pressure. Relief valve discharge piping shall be in accordance with Clauses 4.6 and 6.1.3. C.3.4 Indicators The following shall be fitted to allow monitoring of operating conditions: (a) Gas pressures – A pressure gauge complying with Clause 3.6 shall be mounted in each

stage of gas compression. (b) Lubricating oil pressure(s) (if applicable) – Equipment utilising a pressure lubrication system

shall be fitted with an oil pressure gauge(s). (c) Crankcase pressure (if applicable) – Compressors with a crankcase operating under positive

pressure should be fitted with a crankcase pressure gauge to monitor machinery wear. (d) Temperature(s) – Temperature measurement points shall be provided on the inlet and outlet

of each stage of compression (outlet of intercooler). (e) Oil levels – Provision shall be made for checking all oil levels.

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Annex C Typical layout of static gas storage units

(Informative)

Building Gas storage unit

Gas storage unit

1 m

1 m

Boundary (240/240/240 FRL wall)

See Table 4.1

See Table 4.1

see Clause 4.3.6

Edge of kerb (required only if manoeuvring vehicles in this area)

Security fence

1 m

Public place

A

A

SECTION A- A

0.2 m

1.8 m

Roof (optional)

1.6 m max.

1.1 m max.*

* if vertical cylinders

PLAN VIEW

Ventilation

Gas storage unit

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Annex D Typical arrangement of refuelling station valving system

(Informative)

Gas storage unit Gas storage

unit

Storage security fence

Storage unit isolating valve

Supply line

Master shut-off valve

Refuelling hose isolating valve

Refuelling hose

Refuelling hose valve

Refuelling nozzle

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Annex E Vehicle refuelling procedure

(Normative) It is the responsibility of the refueller to ensure that the correct refuelling procedure is used and appropriate actions are taken in the event of dispensing equipment malfunction or failure. F.1 Before refuelling (a) The CNG vehicle identification labels are approved and on the vehicle registration plate(s). (a) There is no naked flame, no smoking, no electrical appliance being used, within 3 m of the

refuelling vehicle. (b) The vehicle hand brake is applied and the vehicle parked in gear or “P” with automatic

transmission. (c) The engine is switched off. (d) The vehicle CNG cylinders are within periodic retest life. This is done by checking that the

retest date displayed on the CNG vehicle Information Plate has not passed. (e) There are no leaks. F.2 Refuelling procedure (a) Remove the dust cap from the vehicle’s refuelling receptacle. (b) Ensure that the refuelling receptacle is in good condition. (c) Connect the refuelling hose to the vehicle refuelling receptacle. (d) Open the refuelling hose valve and ensure that the refuelling connection is not leaking. (e) Slowly open the refuelling hose isolating valve. (f) Close refuelling hose isolating valve on (automatic) completion of fill. (g) Close refuellling hose valve. (h) Remove refuelling hose from the vehicle refuelling receptacle and replace it on the

dispenser. (i) Check that there are no leaks. (j) Replace dust cap. F.3 Action in the event of mechanical failure of dispenser equipment or on-

board CNG equipment F.3.1 If major hose or piping leaks develop during refuelling, push the nearest emergency shut-down push button in the fuel dispensing area. F.3.2 Inform refuelling station staff immediately. F.3.3 In the event of identified or suspected leaks, do not attempt to start vehicle and drive away. The vehicle, if it needs to be moved away from the dispensing area, shall be manually pushed or pulled by external power (e.g. another vehicle) which is at least 3m away from the leaking vehicle. F.3.4 Gas can leak back from the vehicle due to malfunction of the on-board refuelling receptacle check valve (the symptom of which is the inability of the refuelling connection to be disconnected after the refuelling hose valve is closed). In this event, take the following steps: (a) Close the on-board service isolation valve. (This will isolate the on-board CNG cylinders from

the refuelling receptacle to prevent more gas from flowing back through the faulty check valve, thus enabling the refuelling connection to be depressurised for disconnection).

(b) Disconnect the refuelling hose from the vehicle.

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Feedback Form

To : Programme Director Standardisation Department SPRING Singapore

2 Bukit Merah Central Singapore 159835

E-mail: stn@spring.gov.sg Fax : (65) 62786990 Technical Reference for (input title) Specific: (Please use the format below)

S/No Clause no. in the

TR

Comments (To be supported with

reasons)

Proposed changes

General:

Submitted by : Name (Spelt in full) :

Company :

Designation :

Postal address :

Tel no. :

Fax no. :

E-mail :

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ABOUT THE STANDARDS, PRODUCTIVITY AND INNOVATION BOARD (SPRING SINGAPORE) The mission of the Standards, Productivity and Innovation Board, or SPRING Singapore in short, is to raise productivity so as to enhance Singapore’s competitiveness and economic growth for a better quality of life for our people. In carrying out its mission, SPRING Singapore focuses on three areas: productivity and innovation, standards and conformance, and small and medium-sized enterprises (SMEs) and the domestic sector. Productivity and Innovation The Productivity and Innovation focus has four key thrusts: promotion, business excellence, people excellence and service excellence. Under its promotion thrust, SPRING Singapore spearheads the national Productivity and Innovation Movement. The movement aims to cultivate strong commitment to productivity and innovation in all sectors of the economy and to develop a creative workforce and innovative enterprises. SPRING Singapore serves as Secretariat to the National Innovation Council. Using its internationally recognised Business Excellence programme, SPRING Singapore assists organisations to systematically achieve world-class standards of business excellence. At the apex of the programme is the Singapore Quality Award (SQA). Under its People Excellence thrust, SPRING Singapore initiates leading-edge programmes to enhance the capabilities of the workforce. This enables them to scale new heights and achieve higher levels of productivity. SPRING Singapore administers the Skills Development Fund (SDF), which provides incentives to help companies defray the cost of training their employees. The incentives are financed through collections from the Skills Development Levy imposed on employers. In view of the importance of service quality to competitiveness, SPRING Singapore spearheads Service Excellence in Singapore. The goal is to raise service quality levels in Singapore to world-class standards. Standards and Quality The focus area of Standards and Quality has two major thrusts: standardisation and conformity assessment, and measurement infrastructure development. These are aimed at enhancing productivity, facilitating market access, ensuring safety and health, and protecting the environment. As the national standards body, SPRING Singapore administers the Singapore standardisation programme, which involves the development and implementation of standards in industry. Please visit www.standards.org.sg for more information. As standards and conformance issues can be potential barriers to trade, SPRING Singapore actively supports the government’s Free Trade Agreement (FTA) strategy to ensure market access. As the national authority for the accreditation of conformity assessment bodies, SPRING Singapore audits and accredits quality systems and the competence of quality system certifiers, inspection bodies, and testing and calibration laboratories. SPRING Singapore enforces the Weights & Measures Act and Regulations to protect consumers by ensuring that market transactions based on weights and measures are accurate, fair and comply with the relevant standards. As the Safety Authority, SPRING Singapore administers the Singapore Consumer Protection (Safety Requirements) Registration Scheme to ensure that the controlled goods used by consumers in Singapore are safe. As Singapore's national metrology institute, SPRING Singapore ensures that the measurement infrastructure adequately supports the growing needs of industry. It maintains Singapore’s national

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measurement standards for use by the industry, and provides the vital link between measurements carried out in Singapore and those in the international system. SMEs & Domestic Sector The SMEs and Domestic Sector area of focus has two thrusts: broad-based enterprise upgrading and industry transformation. SPRING Singapore serves as the first point of contact for SMEs that need information and assistance for upgrading. As the lead agency spearheading the upgrading of SMEs, it adopts a total approach to developing SMEs into vibrant and resilient enterprises. SPRING Singapore spearheads the transformation of the domestic sector. The goal is to create a vibrant, dynamic and resilient domestic sector that is able to contribute significantly to the overall economy. SPRING Singapore administers two key financial incentive schemes for SMEs. The first is the Local Enterprise Finance Scheme (LEFS), which is a fixed interest rate loan for SMEs to expand and develop new capabilities. The second is the Local Enterprise Technical Assistance Scheme (LETAS), which is a consultancy grant scheme to help SMEs acquire new competencies in operational management. SPRING Singapore 2 Bukit Merah Central Singapore 159835 Tel: (65) 6278 6666 Fax: (65) 6278 6667 E-mail: queries@spring.gov.sg Website: http://www.spring.gov.sg

ABOUT THE NATIONAL STANDARDISATION PROGRAMME

Under the national standardisation programme, SPRING Singapore helps companies and industry to meet international standards and conformity requirements by creating awareness of the importance of standardisation to enhance competitiveness and improve productivity, co-ordinating the development and use of Singapore Standards and setting up an information infrastructure to educate companies and industry on the latest developments. SPRING Singapore is vested with the authority to appoint a Standards Council to advise on the preparation, publication and promulgation of Singapore Standards and Technical References and their implementation. Singapore Standards are in the form of specifications for materials and products, codes of practice, methods of test, nomenclature, services, etc. The respective standards committee will draw up the standards before seeking final approval from the Standards Council. To ensure adequate representation of all viewpoints in the preparation of Singapore Standards, all committees appointed consist of representatives from various interest groups which include government agencies, professional bodies, tertiary institutions and consumer, trade and manufacturing organisations. Technical References are transition documents developed to help meet urgent industry demand for specifications or requirements on a particular product, process or service in an area where there is an absence of reference standards. Unlike Singapore Standards, they are issued for comments over a period of two years before assessment on their suitability for approval as Singapore Standards. All comments are considered when a technical reference is reviewed at the end of two years to determine the feasibility of its transition to a Singapore Standard. Technical References can therefore become Singapore Standards after two years, continue as Technical References for further comments or be withdrawn.

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In the international arena, SPRING Singapore represents Singapore in the International Organisation of Standardisation (ISO), the International Electrotechnical Commission (IEC), the Asia-Pacific Economic Co-operation (APEC) Sub-committee for Standards and Conformance (SCSC) and in the ASEAN Consultative Committee for Standards and Quality (ACCSQ).