IGEM Draft Technical Standards - EU Skills Network

INSTITUTION OF GAS ENGINEERS AND MANAGERS IGEM/TSP/13/224

IGEM/UP/5 Edition 2 Communication XXXX

Founded 1863 Royal Charter 1929 Patron Her Majesty the Queen

COMPRESSED NATURAL GAS FUELLING STATIONS DRAFT FOR COMMENT 1

This draft Standard IGEM/UP/5 Edition 2 has been prepared by a Panel Chaired by Dr Richard Marrow.

2

This Draft for Comment is presented to Industry for comments which are required by Monday 14th October 2013, and in accordance with the attached Reply Form.

3

This is a draft document and should not be regarded or used as a fully approved and published Standard. It is anticipated that amendments will be made prior to publication. It should be noted that this draft Standard contains intellectual property belonging to IGEM. Unauthorised copying or use by any unauthorised person or party is not permitted.

4

This is a copyright document of the Institution of Gas Engineers and Managers. Enquiries should be addressed in the first instance to: Matthew Sherwood IGEM IGEM House 26-28 High Street Kegworth Derbyshire, DE74 2DA Tel: 01509 678188 Mob: 07904 633037 Fax: 01509 678198 Email: [email protected]

The organisations to which this Draft has been circulated are: Association of Independent Gas Transporters (AIGT) Association of Registered Gas Installers (ARGI) British Standards Institution (BSI) BPEC CAPITA Chartered Institution of Building Services Engineers (CIBSE) The Chartered Institute of Plumbing and Heating Engineering (CIPHE) CITB CORGI DIRECT District Network Operators (DNO) Collaboration Forum Energy Institute (EI) Energy Networks Association (ENA) EU Skills Gas Forum Gas Industry Safety Group (GISG) Gas Safe Register Gas Vehicle Hub Health & Safety Executive (HSE) Health & Safety Executive Northern Ireland (HSENI) Building and Engineering Services Association (B&ES) (was HVCA) ICOM Energy Association *Large Business Forum Knowledge Transfer Network (Transport) Low Carbon Vehicle Partnership National Grid NGV Network Northern Gas Networks (NGN) NICEIC Office of Gas and Electricity Markets (OFGEM) Organisation of Professional Gas Operatives (OPGO) Energy and Utilities Alliance (EUA) (was SBGI) Scotia Gas Networks (SGN) UKLPG Wales & West Utilities (WWU)

Founded 1863 Royal Charter 1929 Patron: Her Majesty the Queen

IGEM/UP/5 Edition 2 Communication xxxx

Compressed Natural Gas fuelling stations

Draft for Comment

Founded 1863 Royal Charter 1929 Patron: Her Majesty the Queen

IGEM/UP/5 Edition 2 Communication xxxx

Compressed Natural gas fuelling stations

Draft for Comment

Price Code: XXX © The Institution of Gas Engineers and Managers IGEM House High Street Kegworth Derbyshire, DE74 2DA Tel: 0844 375 4436 Fax: 01509 678198 Email: [email protected]

Copyright © 2013, IGEM. All rights reserved Registered charity number 214001 All content in this publication is, unless stated otherwise, the property of IGEM. Copyright laws protect this publication. Reproduction or retransmission in whole or in part, in any manner, without the prior written consent of the copyright holder, is a violation of copyright law. ISBN XXX X XXXXXX XX X ISSN XXXX XXXX Published by the Institution of Gas Engineers and Managers Previous Publications: XXXXXXXXXXXXXXXXXXX For information on other IGEM Standards visit our website, www.igem.org.uk

IGEM/UP/5 Edition 2 (Draft for comment)

CONTENTS SECTION

PAGE

1

Introduction

1

2

Scope

3

3

Legal and allied considerations

5

4

Competency and quality assurance

12

5

General provisions

13

6

General principles of design and installation

15

7

Location and layout of equipment

20

8

Piped gas supply

24

9

Stored LNG supply

25

10

Mobile Storage Supply

26

11

Gas compressors (including ancillaries)

27

12

Storage facility (including ancillaries)

30

13

Station pipework and ancillary devices

32

14

Dispenser

35

15

Electrical equipment and wiring

38

16

Testing, purging and commissioning

39

17

Signs, markings and instructions

40

18

Procedures

41

19

Emergency shutdown procedures

42

1

Glossary, acronyms, abbreviations and units

44

2

References

47

3

Hazardous area zones

50

4

Separation distances

51

5

Example of typical CNG fuelling Station components

52

6

Fuelling station – informative diagram

53

7

General safety considerations for LNG storage facilities

54

APPENDIX

©IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk.


8

Guidelines for minimum operational and maintenance requirements

61

9

Inspection of gas carrying equipment, operation and emergency procedures and maintenance schedules

66

10

CNG storage in below ground pits

68

©IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk.


SECTION 1 : INTRODUCTION 1.1

This Standard supersedes withdrawn Standard IGE/UP/5 Part 3 – Natural Gas Vehicles: Filling Station Operations, which is obsolete.

1.2

This Standard has been drafted by a Panel appointed by the Institution of Gas Engineers and Managers’ (IGEM’s) Gas Utilization Committee, subsequently approved by that Committee and published by authority of the Council of the Institution.

1.3

The intent of this Standard is to provide requirements for design, construction, testing, commissioning and guidance on general operation and maintenance of compressed natural gas (CNG) fuelling stations and facilities. It is addressed to both manufacturers and installers, for whom this document provides the basic principles for the design and installation of facilities and parts thereof, and to operators, for whom the minimum requirements for safe operation are given. It also serves as a basis for the inspection of Natural Gas (NG) fuelling stations. It is necessary to ensure, through the use of appropriate components and materials, that CNG fuelling stations and their components, when correctly constructed, operated and maintained are permanently safe and operational. Preventive measures shall be taken to ensure protection against fire and explosion.

1.4

It is now widely accepted that the majority of accidents in industry generally are in some measure attributable to human as well as technical factors in the sense that someone's actions initiated or contributed to the accidents or someone could have acted better to avert them.

1.5

It is therefore necessary to give proper consideration to the management of these human factors and the control of risk. See for instance HSG48 and HSG65.

1.6

The document makes use of the terms "should", "shall" and “must” when prescribing particular requirements:

•

the term “should” prescribes a requirement which, it is intended, will be complied with unless, after prior consideration, deviation is considered to be acceptable.

•

the term “shall” prescribes a requirement which, it is intended, will be complied with in full and without deviation

•

the term “must” identifies a requirement by law in Great Britain (GB) at the time of publication

1.7

Such terms may have different meanings when used in legislation, or Health and Safety Executive (HSE) Approved Codes of Practice (ACoPs) or guidance, and reference needs to be made to such statutory legislation or official guidance for information on legal obligations.

1.8

Requests for interpretation of this Standard in relation to matters within its scope, but not precisely covered by the current text, should be addressed in writing to Technical Services, IGEM, IGEM House, High Street, Kegworth, Leicestershire, DE74 2DA, and will be submitted to the relevant Committee for consideration and advice, but in the context that the final responsibility is that of

1 ©IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk.


the engineer concerned. If any advice is given by, or on behalf of IGEM, this does not relieve the engineer of his or her obligations. 1.9

This Standard was published in xxxx.



SECTION 2 : SCOPE 2.1

This Standard covers the design, construction, installation, testing, commissioning and operation and maintenance of fuelling stations which deliver CNG for use as a vehicle fuel or for filling mobile storage units (Mother Station), which are supplied by either:

• • • • 2.2

piped Natural Gas (NG) from the supply network, liquefied natural gas (LNG) supply from on-site storage, a mobile CNG storage unit, or a piped biomethane supply.

This Standard applies to CNG fuelling stations for Maximum Operational Pressure (MOP) not exceeding 300 bar. Note 1:

This Standard may be used as general guidance for stations for higher MOPs providing due cognisance is given to specifications, safety distances and hazardous areas etc.

Note 2:

Fuelling station the system.

inlet

valve

to

be

defined

as

a

transition

designed material point

in

2.3

This Standard applies to fuelling stations delivering CNG as defined by BS EN 437.

2.4

Mobile storage units containing on-board ancillaries to enable vehicle fuelling from the mobile unit (i.e. a mobile fuelling station) are covered by the applicable parts of this Standard. Note:

2.5

Mobile storage units (with or without on-board ancillaries are covered by the Regulations Concerning the International Carriage of Dangerous Goods by Rail (RID) / European Agreement concerning the International Carriage of Dangerous Goods by Road (ADR).

Fuelling stations dispensing LNG are not covered by the scope of this Standard. Note: Fuelling stations dispensing LNG are covered by British Compressed Gases Association (BCGA) CP41.

2.6

Vehicle Refuelling Appliances (VRA) are not covered by this Standard.

2.7

The scope of the Standard includes fuelling stations of the following types (as shown in Appendix 6):

•

public access (self-service or assisted) fast fill (metered/not metered)

•

private access (metered/not metered)

• •

timed on-site fill of vehicles fast fill of vehicles

•

fuelling stations supplying mobile storage units (Mother Stations)

•

daughter fuelling stations supplied from mobile storage units (Daughter Stations)

•

mobile refuelling stations (Daughter Stations)



2.8

The CNG fuelling facility may be integrated with new or existing fuelling facilities for other fuels, noting that by doing so this may impact the site licensing conditions.

2.9

This Standard applies to private and commercial stations having fast and/or timed fuelling dispensers. If fuelling stations are intended to be used by the general public, due regard needs to be taken to any additional public safety, security and trading standards issues.

2.10

Guidance on the operation and maintenance of fuelling stations is given in Appendix 8.

2.11

All pressures quoted are gauge pressures, unless otherwise stated.



SECTION 3 : LEGAL AND ALLIED CONSIDERATIONS This Standard is set out against a background of legislation in force in GB at the time of publication. Similar considerations are likely to apply in other countries and reference to the appropriate national legislation will be necessary. The following legal and allied considerations outlined are particularly relevant. Appendix 2 lists legislation, guidance notes, Standards etc. which are identified within this Standard as well as further items of legislation that may be applicable. Where Standards are quoted, equivalent national or international Standards etc. equally may be appropriate. Unless otherwise stated, the latest version of the referenced document should be used. 3.1

THE GAS ACT

3.1.1

In particular, the Gas Act stipulates requirements for:

•

notification to the gas supplier and the gas transporter (GT) of the intention to install a compressor

• •

the fitting and maintenance of a supply protection device the avoidance of affecting the supply system.

3.1.2

The user of a gas compressor must provide written notification to the gas supplier and the GT of the intention to connect a compressor to the public gas supply network. The user must provide adequate protection for the gas supply pipework against high pressure being fed back into the supply so exceeding the maximum operating pressure (MOP) of that pipework or of any component contained within it. For this reason, the gas supplier and the GT must be provided with evidence that all appropriate safeguards have been taken.

3.1.3

Before a compressor that is to be fitted to an installation connected to the public gas supply network is considered acceptable for operation, it is required (as permitted by the Gas Act) by the gas supplier and the GT that suitable protective devices be fitted and maintained by the compressor operator. The gas supplier and the GT must also be satisfied that no undue compressor induced perturbations are imposed on the metering system nor into the gas supply. Usually, this will mean demonstrable compliance with relevant published Standards.

3.2

HEALTH AND SAFETY AT WORK ETC. ACT (HSWA) HSWA applies to all persons involved with work activities, including employers, the self-employed, employees, designers, manufacturers, suppliers etc. as well as the owners of premises. It places general duties on such people to ensure, so far as is reasonably practicable, the health, safety and welfare of employees and the health and safety of other persons such as members of the public who may be affected by the work activity. All persons engaged in the design, construction, commissioning, operation, maintenance and alteration of pipework must be competent to carry out such work. Competency is achieved by an appropriate combination of education, training and practical experience.



3.3

MANAGEMENT OF HEALTH AND SAFETY AT WORK REGULATIONS (MHSWR) Linked closely with specific duties under GS(I&U)R (see Sub-Section 3.4) MHSWR impose a duty on employers and the self-employed to make assessments of risks to the health and safety of employees, and non-employees affected by their work. They also require effective planning and review of protective measures.

3.4

GAS SAFETY (INSTALLATION AND USE) REGULATIONS (GS(I&U)R) GS(I&U)R are relevant statutory provisions of HSWA setting out general and detailed requirements dealing with the safe installation, maintenance and use of gas systems, including gas fittings, appliances and flues. Note:

GS(I&U)R do not apply to certain premises (see HSL56 Guidance Notes 28 and 29). However, where they do not apply, the principles of GS(I&U)R need to be applied.

GS(I&U)R place responsibilities on those installing, servicing, maintaining or repairing gas appliances, pipework etc. as well as suppliers and users of gas. GS(I&U)R define the type of work that requires persons carrying out such work, or their employers, to be an “approved class of person”, for example Gas Safe registered. The installer must check the safety of any appliance or pipework they install or work on and take appropriate action where they find faults. Where the premises are let or hired out, the landlord or hirer has special responsibilities to ensure that any installer they use for the gas fitting, service or maintenance or safety is a member of an approved class of persons and is competent to carry out such work. If any serious fault is found, the installer must inform both the landlord/hirer, as well as the user, so that such faults can be rectified before further use. 3.5

PROVISION AND USE OF WORK EQUIPMENT REGULATIONS (PUWER)

3.5.1

Work equipment has a wide meaning and includes tools such as hammers, laboratory apparatus, for example Bunsen burners, ladders, lifting equipments and machinery for use at work.

3.5.2

PUWER place duties on employers in relation to selection, suitability, maintenance, inspection, installation, instruction and training, prevention of danger and control of equipment.

3.5.3

More information on PUWER can be found in HSL22. Free leaflets include INDG 291 and INDG 229.

3.6

PRESSURE EQUIPMENT DIRECTIVE (PED)

3.6.1

PED applies to the design of pipework of MOP exceeding 0.5 bar which is designed and installed for a site user, for example a factory occupier. PED is implemented in the United Kingdom (UK) by the Pressure Equipment Regulations (PER) and the Pressure Systems Safety Regulations (PSSR). Compliance with PED can be demonstrated by the use of a harmonised Standard. BS EN 15001-1 and -2 have been specially prepared for the gas industry and include a wide range of materials. Systems falling within the scope of PED must display a CE mark and this must be affixed by an approved person or body. 6 ©IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk.


3.6.2

Other pipework systems “designed and specified” by the consumer and which are thereafter installed and tested by a contractor will not normally fall within the scope of PED. Sections of pipework designed and manufactured “off-site” will, generally, always fall within the scope of PED if designed and specified by the contractor, as is the normal procedure within the UK. Systems in which the pressure (bar) times the volume (litres) is less than 250 are partially exempt from PED on the basis that they have a low contained energy. Pipework of diameter not greater than 25 mm nominal size is also partially exempt.

3.6.3

There is also a duty on the user of an installed system within the scope of PED not to allow the system to be used until they have a written scheme of examination covering protection devices, pressure vessels and parts, which if they fail, give rise to danger. The scheme of examination must be drawn up by a “competent person” and the system must be examined in accordance with the written scheme of examination by a “competent person”. The more complex a system is, the more qualifications, experience and training are needed to ensure competence. Guidance on the selection of competent persons is given in HSL122. Users (or owners) of pressure systems are free to select any competent person they wish, but they have to take all reasonable steps to ensure that the competent person selected can actually demonstrate competence i.e. the necessary breadth of knowledge, experience and independence. In judging levels of competence, users or owners may wish to know that a national accreditation scheme has been developed by the United Kingdom Accreditation Service (UKAS) for bodies that provide services of this nature.

3.7

PRESSURE EQUIPMENT REGULATIONS (PER) PER are intended to allow the free trade of pressure equipment throughout the European Union (EU). PER deal with the manufacture, design and supply of pressure equipment. They impose duties on the responsible person. Note 1:

A “responsible person” is defined as “the manufacturer or his authorised representative established within the Community; or where neither the manufacturer nor his authorised representative is established within the Community, the person who places the pressure equipment or assembly on the market or puts it into service as the case may be.”

Note 2:

“Pressure equipment” is defined as “vessels, piping, safety accessories and pressure accessories; where applicable, pressure equipment includes elements attached to pressurised parts, such as flanges, nozzles, couplings, supports lifting lugs and similar.”

Note 3:

The duties on the “responsible person” are to ensure that pressure equipment:

• • • •

satisfies the relevant essential requirements has undergone the relevant conformity assessment procedure, if applicable has had the CE mark affixed by the manufacturer, if applicable has had the declaration of conformity drawn up by the manufacturer is, in fact, safe.

Note 4:

Not all pressure equipment is covered by PER. There are 21 categories of exceptions, detailed in Schedule 1 of PER.


IGEM/UP/5 Edition 2 (Draft for comment) Note 5:

The relevant conformity assessment procedure is determined by the classification of the pressure equipment according to criteria laid down in PER. The classification system results in equipment being placed in one of 5 categories depending on the inherent level of hazard within the system. The category then determines the range of conformity assessment modules relevant to that equipment. The modules are designed to allow the manufacturer to choose between a quality assurance route or type testing.

3.8

PRESSURE SYSTEMS SAFETY REGULATIONS (PSSR)

3.8.1

PSSR impose duties on designers, importers, suppliers, installers and user or owners to ensure that pressure systems do not give rise to danger. This is done by the correct design installation and maintenance, provision of information, operation within safe operating limits and, where applicable, examination in accordance with a written scheme of examination drawn up or approved by a competent person (as defined in PSSR).

3.8.2

Relevant fluids include NG at a pressure greater than 0.5 bar i.e. above atmospheric pressure. A pressure system would include bulk storage tanks, pipelines and protective devices. Once the pressure in the pipework drops below 0.5 bar, and the user/owner can show clear evidence that the system does not contain, and is not liable to contain, a relevant fluid under foreseeable operating conditions, then that part of the system is no longer covered by PSSR. This is likely to be the case after the pressure relief valve associated with a pressure reducing valve which takes the pressure to below 0.5 bar, for example at the entry to a building but note the special requirements placed on protective devices in such systems (see paragraph 110b of HSL122). PSSR also apply to pipelines and their protective devices in which the pressure exceeds 2 bar (see Schedule 1 part 1 item 5 of HSL122).

3.8.3

More information is available in HSL122 and some information is presented in INDG 261 and INDG 178.

3.9

ELECTRICITY AT WORK REGULATIONS These Regulations apply to a wide range of electrical work, from overhead power lines to the use of office computers and batteries and include work on gas equipment using electrical energy. They are concerned with the prevention of danger from electric shock, electric burn, electrical explosion or arcing, or from fire or explosion initiated by electrical energy. They impose duties on every employer, employee and self-employed person and require that persons engaged in electrical work be competent or be supervised by competent persons. Note:

3.10

HSR25 provides guidance on the Regulations.

CONTROL OF NOISE AT WORK REGULATIONS Under these Regulations, the employer is required to identify any potential injurious noise sources and carry out an assessment when an employee is exposed to a level of noise in excess of the first action level of a daily personal exposure of 85 dB(A). Action is then required to reduce noise at source so far as is reasonably practicable. Only then can consideration be given to hearing protection. A duty is also placed on manufacturers and suppliers to provide information on the noise likely to be generated by their product.



3.11

CONFINED SPACES REGULATIONS These Regulations apply to a large range of confined spaces. The supplier or designer of an enclosure and equipment within it is required to perform a risk assessment of the enclosure with respect to safe access and egress and to give clear instructions to operators on access/egress as well as to what actions to take in the event of a gas alarm occurring. Employers and the self employed should prevent entry into confined spaces unless avoidance is not reasonably practicable and unless there is a system of work which renders the work safe. They are also required to have specific emergency arrangements in place.

3.12

CONSTRUCTION (DESIGN AND MANAGEMENT) REGULATIONS (CDM) CDM impose duties on designers, clients (and their agents), developers, planning supervisors and principal contractors. Not all the regulations apply to all construction projects. Further information is given in HSL144. For a notifiable project (as defined in CDM) the planning supervisor must notify HSE before construction work commences. Construction includes the alterations, repair redecoration, maintenance, decommissioning or demolition of a structure. It also covers installation, commissioning maintenance or removal of gas services.

3.13

SUPPLY OF MACHINERY (SAFETY) REGULATIONS These Regulations set out “essential requirements” written in general terms, which must be met by manufacturers/suppliers before a product may be supplied within the European Community. European Standards provide the detail on the essential requirements. Machinery, as defined, once having been verified against the relevant Standards, can then be affixed with the CE mark. The manufacturer or importer will have to be able to assemble a technical file detailing information on the health and safety considerations that went into the design of the product.

3.14

REPORTING OF INJURIES, DISEASES AND DANGEROUS OCCURRENCES REGULATIONS (RIDDOR)

3.14.1

RIDDOR require employers, self employed people or those in control of work premises to report certain work related accidents, diseases and dangerous occurrences.

3.14.2

Other people have duties to report certain gas incidents which may not appear to be work related:

• •

death or major injury arising out of the distribution, filling, import or supply of NG or LPG should be reported by the conveyor for NG and the filler, importer or supplier for LPG dangerous gas fittings (as defined in RIDDOR) should be reported by a "member of a class of persons".



3.14.3

Major injuries, death and dangerous occurrences must be notified immediately, for example by telephone, to the enforcing authority by the "responsible person" as defined by RIDDOR. Reports can be made to the Incident Contact Centre:

• •

for fatal and major injuries only, telephone on 0845 300 9923 (opening hours Monday to Friday 8.30 am to 5 pm) and complete appropriate on-line form all other reports at HSE website www.hse.gov.uk

Complete the appropriate online report form listed below.

• • • • • • •

report report report report report report report

of of of of of of of

an injury a dangerous occurrence an injury offshore a dangerous occurrence offshore a case of disease flammable gas incident a dangerous gas fitting.

This form will then be submitted directly to the RIDDOR database and a copy issued to the person making the report. On-line written reports are to be submitted within the required timescale (10 days, or 14 days for dangerous gas fittings). Other reports should be made as soon as practicable and within 10 days of the incident. 3.14.4

HS(L)73 contains detailed guidance on RIDDOR, including a full list of injuries etc. that need reporting.

3.14.5

IGE/GL/8 provides guidance on the reporting and investigation of gas-related incidents.

3.15

DANGEROUS SUBSTANCES AND EXPLOSIVE ATMOSPHERES REGULATIONS (DSEAR) DSEAR are concerned with protection against risks from fire, explosion and similar events arising from dangerous substances used or present in the workplace. DSEAR require that risks from dangerous substances are assessed, eliminated or reduced. They contain specific requirements to be applied where an explosive atmosphere may be present and require the provision of arrangements to deal with accidents, emergencies etc. and provision of information, training and use of dangerous substances. DSEAR also require the identification of pipelines and containers containing hazardous substances. The following publications contain details of DSEAR and their application:

• • • • • •

INDG 370 HSL134 HSL135 HSL136 HSL137 HSL138.

All gas systems except those in domestic parts of buildings fall within the scope of DSEAR. This requires that a risk assessment be completed for each premise 10 ©IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk.


to determine if any hazardous area exists and its extent. Normally, systems of MOP not exceeding 0.5 bar do not require the use of certified electrical components if correctly installed, tested and maintained. 3.16

THE CARRIAGE OF DANGEROUS GOODS AND USE OF TRANSPORTABLE PRESSURE EQUIPEMENT REGULATIONS These regulations implement and enforce in the UK provisions from the European Agreement concerning the International Carriage of Dangerous Goods by Road (ADR). ADR is intended to increase the safety of international transport of dangerous goods by road including gases (including compressed, liquified and dissolved under pressure gases and vapours)

3.17

REGULATIONS CONCERNING THE INTERNATIONAL CARRIAGE OF DANGEROUS GOODS BY RAIL (RID) These regulations implement and enforce in the UK provisions from the International Carriage of Dangerous Goods by Rail (OTIF) including movement of dangerous goods including gases by rail.

3.18

CONTROL OF MAJOR ACCIDENT HAZARD REGULATIONS (COMAH) COMAH apply to industrial installations where certain quantities of specified substances are stored and relate to the measures in place in order to identify and mitigate the risks involved in storing such substances.



SECTION 4 : COMPETENCY AND QUALITY ASSURANCE 4.1

COMPETENCY Any person engaged in the design, construction, commissioning, inspection, operation, maintenance or alteration of a CNG refuelling shall be competent to carry out such work. Note:

This may be achieved by an appropriate combination of education, training, and practical experience.

4.2

QUALITY ASSURANCE

4.2.1

Materials All materials and equipment shall be selected to ensure safety and suitability for the conditions of use, in accordance with relevant legislation, Standards, technical specifications and this Standard.

4.2.2

Inspection Particular emphasis shall be placed on the inspection of materials (before and following assembly), jointing, coatings and testing.



SECTION 5 : GENERAL PROVISIONS An example layout of components is given in Appendix 5. 5.1

GAS COMPRESSOR In general, gas compressors for Natural Gas fuelling stations produce high pressure lifts. Compressors may supply to bulk storage and/or to a direct fuelling facility. A typical compressor, for example would be a multi-stage machine which may be directly or indirectly driven by an electric motor in stationary facilities. Any compressor shall be in compliance with the essential requirements of European Directive 2006/42/EC on machinery and with EN 1012-1.

5.2

CNG STORAGE CNG may be permanently stored on site to facilitate fast filling of multiple vehicles. For example, storage is provided in banks of multiple vessels to speed up fuelling, to optimise the station design and to limit the number of start/stop cycles of the gas compressor. Often, cylinders are manifolded together to form differing pressure groups to enable a cascade dispensing sequence.

5.3

MOBILE CNG STORAGE Mobile storage units can be filled using specific facilities at CNG fuelling stations. The units must comply with RID/ADR regulations. If the unit is to be used as a mobile CNG refuelling station, by having on-board additional equipment dispensers, they shall also comply with the relevant parts of this Standard.

5.4

LNG STORAGE LNG can be permanently stored on site to supply the station with gas. Gasification equipment will form part of the LNG facility.

5.5

PIPED GAS SUPPLY The station may be supplied with Natural Gas from the local network or with suitable biomethane from a local source.

5.6

DAUGHTER STATION A Daughter Station is a CNG fuelling station which is typically remote from a gas supply and is supplied by mobile storage units. All components of this type of station shall comply with this Standard.

5.7

DISPENSER If CNG fuel is being dispensed for sale, it must contain suitable metering equipment, and meet weights and measures requirements (see Sub-Section 14.2.5) A dispenser comprises for example:

• • •

a dispensing and optional metering unit a filling hose a filling nozzle.



Gas for dispensing is drawn either directly from a compressor or via on-site storage, and then passed into the vehicle CNG cylinder. On a mother station CNG will be dispensed into mobile storage units. The dispenser can be operated in several forms, for example:

• • • • 5.8

manually or automatically operated metered or unmetered a fill-post, which is used on timed fuelling stations assisted or self-service.

FUELLING METHODS Vehicle fuelling can be undertaken in the following ways:

• •

fast-fill timed-fill.

with or without temperature compensation. 5.9

CONTROL SYSTEMS A control system operates the compressor and/or any storage facility in conjunction with the demands of the dispenser and the safety system (see SubSection 6.5).

5.10

DRYER A drying system may be required to control the water content of the gas to comply with relevant Standards including for CNG quality. (See BS EN 437).

5.11

GAS COOLING SYSTEM A system may be required to control the delivered gas temperature.

5.12

FILTRATION If filtration is required it shall be sized for the maximum gas flow and have a suitable collection device and a means of removal/exchange. Differential pressure monitoring should be used to check performance.

5.13

Where it is required to dispense odorised CNG, if a gas drying system is used, suitable odorisation equipment may be required to re-odorise the gas to the required level before it is dispensed. Odorant equipment shall include failure alarms.



SECTION 6 : GENERAL PRINCIPLES OF DESIGN AND INSTALLATION 6.1

GENERAL

6.1.1

All equipment, components, pipework and fittings shall be of a type and manufacture and be assembled in such manner suitable for their intended use, for the full range of pressures, type of gas, temperatures, weather conditions and loadings which may occur under normal and fault conditions. These shall be supported by appropriate certification (such as in EN 10204). These shall be installed and used in accordance with the manufacturer's instructions.

6.1.2

The design of the station shall ensure that all the individual elements are compatible and can be integrated.

6.1.3

Consideration shall be given to pressurisation and depressurisation of components e.g. for removal for maintenance purposes, draining condensate, by the provision of valves, gauges and vent connections to ensure that sections are depressurised before service interventions.

6.1.4

The fuelling station installation shall be sited to minimise risk to users, operating personnel, properties, and environment. More specifically, measures to reduce fire and explosion risks shall be applied in the following order of priority:

• • • • • •

the need for explosion relief and/or flame arrestors strength potential of explosive atmosphere generated by potential leaks or releases prevention of static charge build-up avoidance of ignition sources mitigation of the effects of a fire or explosion asphyxiation hazard in case of natural gas leakage in confined spaces.

Any potential hazardous effects of adjacent premises on the CNG fuelling station shall be considered. The design process shall involve appropriate risk assessment (such as Hazard Identification (HAZID) or Hazard and Operability Analysis (HAZOP) or Failure Mode and Effects Analysis (FMEA)) to determine the adequacy of the proposed systems and procedures to mitigate harm or damage to acceptable levels. Note:

Guidance can be found in IGE/SR/24: Risk assessment techniques.

6.1.5

Materials

6.1.5.1

All material used for the construction of the station shall conform to the required specifications. In particular, documentation provided by the material manufacturer affirming compliance with the specification shall be obtained for all materials used for the production of pressure carrying components. For the main pressure-bearing parts, this shall take the form of a certificate of specific product control. Where a material manufacturer has an appropriate quality assurance system, certificates issued by the manufacturer should identify conformity with the relevant requirements.



6.1.5.2

6.1.6

Materials used for the construction of pressurized parts shall:

•

have suitable properties for all operating conditions which are reasonably foreseeable and for all test conditions. In particular, they should be sufficiently ductile and tough. Moreover, due care should be exercised, in particular, in selecting materials in order to prevent brittle-type fracture, where necessary;

•

be chemically resistant to delivered quality natural gas in accordance with EN 437, and, if applicable, to regenerative produced gases;

• •

not be significantly affected by ageing;

•

be suitable for the intended pressures, pressure cycling and temperatures and the variations thereof;

•

be selected in order to avoid significant undesirable effects when the various materials are put together.

be resistant to corrosion or, alternatively, protected against corrosion by suitable means;

Global conformity CNG fuelling stations under the scope of this Standard may be subject to the global conformity assessment procedure which is applicable for assembled products from a variety of sources under the responsibility of the manufacturer.

6.1.7

Requirements for the various elements of the assembly These shall be appropriate to their normal functioning and also take into account the effect of extraneous forces such as the effects of changes in pressure and temperature, and forces and vibrations set up during manufacturing and assembly. This implies proof of adequate strength either by calculation or by experimental design. All the elements of assembly shall be protected against corrosion by means of suitable systems, such as painting, and/or cathodic protection, taking into account environmental conditions.

6.1.8

Optional components Optional components (e.g. dryers, filters and chillers) shall not impair the operability and safety of the fuelling station.

6.1.9

Working area A sufficient working area for inspection, maintenance and servicing shall be available. Components such as cylinder banks may have to be removed at intervals for revalidation and sufficient area should be made available.

6.1.10

Noise attenuation Noise created during operation and maintenance activities should be minimised. This includes noise generated by compressors and ventilation systems and from pressure reliefs and venting operations.



6.1.11

Collision protection All CNG equipment exposed to the risk of vehicle collision shall be provided with barriers or other protection suitably designed and constructed. Special consideration shall be given to collision protection of the storage and dispenser.

6.1.12

Traffic management

6.1.12.1

Consideration shall be given to the flow of vehicles on the station premises. Greater levels of access may be required where the station is supplied by a mobile storage.

6.1.12.2

Mobile storage vehicles not undertaking supply shall not be permitted to park in the station premises unless in a specially designated area.

6.1.13

Foundation The CNG fuelling station shall be mounted on suitably designed and constructed foundations.

6.1.14

Unauthorized access There shall be adequate means provided such that safety of operation cannot be affected by unauthorized interference. Equipment shall be suitably protected to deter unauthorised access and to minimise the effects of interference, damage and vandalism. Additional precautions may be necessary to protect mobile storage units during supply operations.

6.1.15

Location of components

6.1.15.1

Equipment shall be located either in open air or dedicated enclosures (see Sub-Section 7.6). In all other cases, due consideration shall be given to safety and ventilation requirements.

6.1.15.2

Electrical components shall be suitably rated for their locations. Other ignition sources shall be excluded from hazardous area zones.

6.1.15.3

Planning Consideration shall be given to local planning regulations and permits.

6.1.15.4

Building regulations Consideration shall be given to local building regulations and permits.

6.1.16

Utilities Consideration shall be given to the acquisition of services (e.g. gas supply) to the site.

6.1.17

Petroleum Regulations On multi-fuelled stations, applicable Petroleum Regulations must be complied with.



6.1.18

Isolation A means of safe and secure isolation shall be fitted to:

• • • 6.1.19

the compressor inlet pipework the inlet/outlet of any group/bank of storage pressure vessels each inlet gas supply line of any dispenser.

Emergency escape Adequate means of escape in the case of emergency shall be provided in cases where authorized personnel can be trapped inside compounds.

6.2

GAS COMPOSITION

6.2.1

General Compressed natural gas dispensed by the fuelling station shall be according to BS EN 437.

6.2.2

Gas supplied to the fuelling station The gas supply and metering equipment for the station shall be suitable for the fuelling stations requirements.

6.2.3

Gas supplied to the dispenser Gas supplied to the dispenser shall have a particulate matter level which will not cause malfunction of the dispensing equipment and shall comply with dispenser manufacturer requirements. This also applies to a station supplied from mobile storage (daughter stations).

6.2.4

Gas composition during maintenance Any maintenance or servicing anticipated during operation of the fuelling station shall not affect adversely the composition of gas dispensed from the station.

6.3

SAFETY DEVICES

6.3.1

General

6.3.1.1

Fuelling stations shall be equipped with safety devices that prevent overpressure in any part of the fuelling station and its pipework, and the uncontrolled release of pressurised gas.

6.3.1.2

Safety devices shall be fully independent of other functions, unless their safety function cannot be affected by such other functions. Pressure relief devices shall comply with ISO 4126-1.

6.3.2

Automatically operated safety device The CNG dispensing system shall be equipped with an automatically operated safety device, which will work in such a way that the delivery pressure to the vehicle cannot exceed the MOP (see Sub-Section 6.4).



6.3.3

Safety isolation devices Safety isolation devices shall include at least:

•

an automatic emergency gas isolation valve which isolates:

• the station • storage outlet • dispenser(s).

•

a suitably located emergency shutdown button(s).

The type of automatic valves and actuators fitted shall be suitable for the required duty operation and location. 6.4

DELIVERY PRESSURE AND TEMPERATURE TO THE VEHICLES

6.4.1

The station shall be designed to supply CNG to vehicles having appropriate and suitable CNG storage systems and filling receptacles. Dispensing can be to 200 or 250 bar depending upon the vehicle CNG systems design. The dispenser and refuelling nozzle will determine the size and pressure level, which will be clearly indicated (see Section 17). Note:

Dispensing to 250 bar is usually restricted to commercial vehicle systems and to mobile storage units.

6.4.2

The fuelling station shall control the filling of the vehicle in such a manner (i.e. temperature compensation) as to obtain an on-board gas mass not exceeding the mass corresponding to storage at 200 bar (or 250 bar) and 15°C.

6.5

CONTROL SYSTEM

6.5.1

The control system for the fuelling facility shall ensure the safe delivery of CNG throughout the station. It shall not override or adversely affect any of the essential safety devices or emergency shutdown systems.

6.5.2

All control system components and wiring shall comply with the hazardous area classification requirements.



SECTION 7 : LOCATION AND LAYOUT OF EQUIPMENT 7.1

GENERAL PROVISIONS

7.1.1

Site location shall comply with separation distances as outlined in, Appendix 4.

7.1.2

Site location and layout shall be planned carefully as most of the site components have location restrictions and minimum safety distances and may be affected by hazardous area requirements. If the CNG fuelling facility is integrated with new or existing fuelling facilities of other fuels, the requirements of this Standard and those of the other fuelling facilities shall be fully implemented.

7.1.3

Location The CNG station should be preferably in the open air and in a well ventilated location, but under certain conditions in a separate fit for purpose enclosure. Any security fence or fire wall shall not interfere with the ventilation aspects of the open area or enclosure.

7.1.4

Emergency services Consideration shall be given to accessibility by emergency services and their equipment, such as fire fighters.

7.1.5

Safety distances Equipment shall be suitably separated from other installations and structures by defined safety distances. Appendix 4 gives guidance on the minimum safety distances to be applied.

7.1.6

Fire walls If a fire wall is constructed to provide fire protection of equipment, it shall be of at least 1 hour fire resistant construction, of solid construction. The wall shall be at least as high as the highest component (excluding vent stacks) and have a minimum height of 2 m. The fire wall shall not interfere with the equipment ventilation aspects, maintenance access or escape routes.

7.1.7

Security All of the CNG fuelling station components shall be restricted from unauthorised access. Note:

At a public access station the customers may be authorised to use the dispensers.

In a private access station, security measures should be used to control the access and use of dispensing equipment 7.2

HAZARDOUS AREAS

7.2.1

A hazardous area classification analysis of the fuelling station and its components shall be undertaken and implemented for the location of electrical equipment and other sources of ignition. Special attention shall be given to existing equipment and structures, such as high voltage equipment and overhead cables. Precautions shall be taken for any hazardous areas generated



by other equipment existing on the site (or adjacent to it). Vent terminations (see Sub-Section 7.9) shall also be classified. Further guidance is given in Appendix 3 7.2.2

Hazardous areas classification shall be in accordance with BS EN 60079-10-1.

7.2.3

Hazardous areas may have to be provisionally determined at an early stage in a project to allow electrical equipment to be specified and other potential sources of ignition to be located. However, a comprehensive hazardous area classification drawing shall be produced prior to installation of the fuelling station and shall be based on the requirements in BS EN 60079-10-1.

7.2.4

The hazardous area shall not exceed the boundary of the property unless special provisions are applied. For example the use of suitable containing structures, controlled areas etc.

7.2.5

All identified hazardous areas shall be maintained and reviewed at regular intervals.

7.2.6

To prevent gas transmission between areas of a different hazard classification, cables must be sealed in accordance with BS EN 60079-10-1.

7.3

STORAGE FACILITY (INCLUDING ANCILLARY EQUIPMENT)

7.3.1

Any storage facility shall be installed in a well ventilated location, ideally in the open air. Note 1:

However, where this may have unacceptable aspects, for example, due to safety, security, noise levels, weather protection etc., consideration may be given to the use of a fit for purpose enclosure, with a suitably designed ventilation system. Storage shall not be located in a building.

Note 2:

In exceptional cases, if supported by appropriate risk assessments, consideration may be given to the use of a suitably designed and protected below ground storage facility. More information is given in Appendix 10.

7.3.2

The base of the facility shall be designed to prevent the collection of liquids, for example water, liquid fuels etc., beneath the storage pressure vessels.

7.3.3

Adequate access, including overhead if appropriate, should be given to permit maintenance, removal and exchange of individual banks of storage vessels, dependent upon design, to allow revalidation. Consideration shall be given to the protection of manifold pipework during removal of vessels.

7.3.4

Mobile storage units shall be located in open air well ventilated locations during supply operations.

7.4

COMPRESSORS (INCLUDING ANCILLARY EQUIPMENT)

7.4.1

Any compressor shall be in a well ventilated location, ideally in the open air. However, where this may have unacceptable aspects, for example, due to safety, security, noise levels, weather protection etc., consideration may be given to the use of a fit for purpose enclosure, with a suitably designed ventilation system.

7.4.2

Compressors in buildings shall not be permitted.

7.4.3

Adequate access, including overhead, if appropriate, should be given to permit maintenance, removal and exchange of compressors and auxiliary equipment.



7.5

DISPENSER

7.5.1

Installation shall be in a well ventilated location, ideally in the open air. Installation in buildings shall not be permitted. Dispensers shall be located so that vehicles have adequate space for manoeuvring into and out of the filling location. This shall be similar to normal fuelling station design for other fuels.

7.5.2

Where a timed-fill facility is provided, adequate security protection shall be given to protect against unauthorised interference, particularly during periods of unmanned filling operations.

7.5.3

Where a mobile storage unit is being filled, the dispensing connection point shall be separated from any public or private vehicle fuelling facility and shall be used for mobile storage filling only.

7.6

ENCLOSURES

7.6.1

General Provisions It is preferable to install any compressor or storage facility in the open air. However, where this may have unacceptable consequences, e.g. for safety, security, noise levels, weather protection etc., consideration may be given to the use of a fit for purpose enclosure, with a suitably designed ventilation system. Suitably designed over-pressure reliefs (such as walls of light material, lightly fastened hatch covers, outward opening doors in exterior walls, lightly fastened wall or roofs) shall be provided if identified by the risk assessment.

7.6.1.1

A compressor and storage facility, including their respective ancillaries, may be housed in the same enclosure. Control panels may be installed in a separate compartment within the same enclosure.

7.6.1.2

An enclosure used to house a compressor and/or a storage facility, including their respective ancillaries, shall not be used for any other purpose.

7.6.1.3

A ventilation system shall be provided for the enclosure which:

• • • • •

ensures continuous dilution of the internal volume or be interlocked with a suitable gas detection system, such that a potential gas release will not produce an explosive mixture; ensures that there are no dead spaces where a flammable mixture can accumulate; provides sufficient ventilation for any equipment cooling requirements; uses uncontaminated air taken from inlets suitably positioned so that a flammable mixture cannot be induced; uses ventilation openings which are not subject to inadvertent obstruction. Accoustic treatment shall not reduce the effectiveness of the openings. Openings shall be designed to be free of blockage from liquids or foreign bodies.

Note:

7.6.1.4

Further guidance on compressor enclosures is given in IGEM/UP/6.

A forced (mechanical) ventilation system design shall include controls to ensure safe shutdown and safe maintenance of the system on and following failure of the ventilation system. It may be appropriate to have a combination of both forced (mechanical) and natural ventilation to help facilitate failure of the forced (mechanical) ventilation.



7.6.1.5

Enclosures shall be secured against unauthorised access. Access to the enclosure shall be controlled by suitable procedures to ensure the safety of persons entering.

7.7

CANOPIES

7.8

7.9

Any canopy shall not inhibit natural ventilation and shall be designed to prevent the accumulation of any gas release. GAS DETECTION SYSTEM If a gas detection system is installed, it shall comply with BS EN 60079-29-2. Detectors shall be installed in enclosures for the compressor unit and storage facility. VENTS Certain station equipment may contain control devices which require vents terminating in non-hazardous areas. A hazardous area assessment may be required of the termination points which may affect their position in relation to ignition sources, air intakes and boundaries. This shall be accounted for in the layout of equipment.

7.9.1

Where relief valve vents are manifolded together, operation of any relief valve shall not be impeded or obstructed.

7.9.2

Venting shall be via a suitably designed vent stack.

7.9.3

Where more than one piece of similar equipment (e.g. compressors, dispensers or storage banks) is installed, manifolded vents from each piece of similar equipment shall not be connected together. Note:

This is to prevent potential unsafe interaction when one piece of equipment is being maintained whilst others remain in service.

7.9.4

Relief vent lines shall not be impeded or obstructed.

7.9.5

A hazardous area classification assessment of the vent end points shall be undertaken and applied.

7.9.6

Permanent or temporary ignition sources shall not be permitted within the vent terminal hazardous area.

7.9.7

Safety relief valves shall vent to the atmosphere and the vent pipe end point shall: a)

be facing upward and unimpeded

b)

be located at a non-hazardous area outdoors at a height of at least 3 m above the ground, and at least 1 m higher than any building roof level within the calculated radius

c)

be fitted with a vent terminal designed to take account of the adverse effects of rain, condensation and, foreign bodies.



SECTION 8 : PIPED GAS SUPPLY This section covers a CNG fuelling station receiving a piped supply from a Natural Gas distribution/transmission supply network or from a bio-methane plant. 8.1

GENERAL PROVISIONS

8.1.1

Consideration shall be given to the effects of the operation of a compressor on the gas supply network or bio-methane supply plant.

8.1.2

The gas transportation company (GT) shall be advised of the existence of the installation in order that the anticipated transient flow variations can be checked for compatibility with the overall gas supply/metering system for the site (see Sub-Section 3.1).

8.1.3

Connection to the gas supply network The capacity of the gas supply network shall be sufficient to cope with the gas compressor suction requirements, and compressor operation must not create problems of low flow rate, low pressure, or pulsation for the local gas supply network.

8.1.4

Non-return system A non-return system shall be fitted immediately downstream of the CNG station inlet isolation valve. The system should consist of, as a minimum, two devices, e.g. a non-return device and a pressure operated slam-shut device. Consideration shall be given to installing a suitable filter before the non-return valve.

8.1.5

Low inlet pressure A safety device (e.g. a pressure switch) shall be installed for shutting down the compressor and prevent automatic re-start if the inlet gas pressure to the compressor falls below an acceptable level, as defined by the manufacturer. An indicator should be fitted to identify low pressure induced shut down.

8.1.6

Special equipment It may be necessary to provide gas conditioning equipment, filters and pressure regulation which shall be designed and constructed to appropriate standards. If unodorised gas is to be dispensed, odorising equipment may be required, noting that any dryers may reduce odorant levels. The system shall be designed such that any element can be replaced safely and easily.



SECTION 9 : STORED LIQUEFIED NATURAL GAS SUPPLY 9.1

The LNG storage and supply facility shall be designed, installed, commissioned and maintained by a specialist company. General safety considerations for stored LNG facilities are given in Appendix 7. Note:

General guidance on the principles of storing a cryogenic liquid. For storing a cryogenic liquid at users’ premises BCGA CP36 and BS EN 13458-3 provide general guidance on the principles of operating a storage vessel built to that standard. Fuelling stations dispensing LNG are covered by BCGA CP41.



SECTION 10 : MOBILE STORAGE SUPPLY 10.1

The capacity of the mobile storage supply unit shall be sufficient to satisfy the stations storage and delivery requirements. The design of the connection system shall permit safe and secure connection and disconnection.

10.2

The compressor or storage facility on the station shall be compatible with supply from a mobile storage unit with regards to pressure and quality.

10.3

The mobile storage unit connection point shall be separated from any public or private vehicle fuelling facility and shall be used for mobile storage unloading only.

10.4

The docking area should accommodate at least two mobile storage trailers to enable efficient change-over of supply.

10.5

Docked storage trailers must be secured to prevent movement and suitably earthed during the unloading operation.

10.6

The docking area shall be secure to prevent interference.



SECTION 11 : GAS COMPRESSORS (INCLUDING ANCILLARIES) 11.1

GENERAL PROVISIONS

11.1.1

Gas supplied from compressors The compressor(s) shall incorporate a means to prevent liquid carryover into the storage or dispensing system.

11.1.2

Design

11.1.2.1

The compressor(s) shall be designed for safe operation and should be capable of continuous full load duty.

11.1.2.2

Live parts (mechanical or electrical) shall be protected or located or guarded such that unintentional contact is unlikely with power transmission apparatus and other exposed moving parts, including belts, couplings and fans shall be guarded in accordance with the Machinery Directive.

11.1.2.3

During normal operation the compressor should not vent to the atmosphere.

11.1.3

Vibration The compressor(s) shall be provided with adequate means of balancing, support or mounting to minimise the transmission of mechanical vibration to the structure and connected equipment. The inlet and outlet connections of the compressor(s) shall be designed to prevent the transmission of vibration to pipework and equipment.

11.1.4

Pulsation The compressor(s) shall be provided with a suitable device which protects the outlet system from unacceptable pressure pulsations.

11.1.5

Protection against weather A compressor intended for outdoor installation has to be adequately protected against weather conditions to ensure safe and reliable operation. Precautions shall be taken in order to protect the compressor and ancillaries from heat radiation (i.e. sun radiation).

11.1.6

Accessibility Components, integral parts and user controls that may require adjustment or replacement during servicing, operation and maintenance shall be readily accessible.

11.2

11.2.1

GAS RECOVERY General provisions Consideration should be given to recovery of gas released from separators using a suitable system which is acceptable to the compressor manufacturer.



11.3

CONDENSATE DRAINAGE AND DISPOSAL

11.3.1

A safe and controlled system shall be used to facilitate liquid removal from the point of condensate collection. In particular, any pressure relieved during this action shall not endanger the operator or any other person.

11.3.2

Any liquid removed shall be considered as hazardous waste and shall be disposed of accordingly.

11.4

STAGE SAFETY DEVICES

11.4.1

The compressor system shall be fitted with shutdown devices in the event of the following:

• • • •

low gas inlet pressure high gas inlet pressure if exceeding the compressor inlet pressure can occur high gas outlet pressure high outlet temperature at the final stage

and when applicable:

• • • •

low lubricant pressure/level high hydraulic oil temperature low hydraulic oil level high temperature of cooling fluid.

Other adverse conditions may need to be taken into account. 11.4.1.2

The compressor(s) shall shut down safely in the event of loss of energy supply (to the compressor drive).

11.4.1.3

General provisions Each stage of the compressor shall be fitted with own safety relief valve.

11.4.1.4

Resetting of the control system following over pressure shall be undertaken by manual means.

11.4.1.5

Relief Valve The final stage of the compressor shall have a full capacity relief valve which shall vent to the atmosphere or may vent to a recovery vessel, which itself shall have a relief valve which vents to the atmosphere.

11.5

DELIVERY LINE NON-RETURN VALVE

A suitable non-return device shall be fitted to the compressor discharge line to prevent loss of downstream pressure when the compressor is unloading and when the liquid separator is draining.



11.6

11.6.1

SUCTION LINE COMPONENTS General provisions A normally closed automatic valve shall be fitted to isolate the gas supply to the compressor whenever the compressor is not in operation.

11.7

INSTRUMENTATION

11.7.1

An hours run meter shall be provided for the purpose of identifying maintenance intervals.

11.7.2

Indicators shall be provided to show that the electrical supply is "on" and that the motor is operating.

11.8

MARKINGS

11.8.1

A compressor shall be suitably marked by the manufacturer according to the applicable requirements. It shall bear the following markings in a durable, legible manner on a firmly attached plate:

• • • • • •

identification of compressed gas (e.g. CNG compressor) identification of the manufacturer and, where appropriate, identification of his authorized representative established within the country the year of manufacture unique identification of the compressor, such as type, series or batch identification and/or serial number essential limits such as maximum allowable pressures and temperature; rated power in kW and supply voltage in V maximum operating pressure of the compressor.

11.8.2

All electric motors and ancillaries shall be marked as suitable for use in the applicable hazardous area according to applicable Standards. All operational valves of the compressor and ancillaries shall be labelled with identification tags, displayed on the Piping and Instrumentation Diagram (P&ID) diagram.

11.8.3

The P&ID diagram shall be placed adjacent to the compressor.

11.9

INSTRUCTIONS The compressor(s) shall be provided with comprehensive installation instructions, diagrams, maintenance (including purging procedure), servicing and user instructions.



SECTION 12 : STORAGE FACILITY (INCLUDING ANCILLARIES) 12.1

STORAGE PRESSURE VESSELS

12.1.1

All CNG storage vessels shall comply with the European Directive 97/23/EC, BS EN 13445-1 and BS EN 1964.

12.1.2

Horizontal cylinders shall not be in direct contact with each other. A minimum distance shall be kept to allow regular visual inspection at intervals.

12.2

PRESSURE RELIEF DEVICES

12.2.1

At least one suitable non-temperature dependent safety device shall be fitted to protect the storage system from over-pressurisation, with a discharge rate that is adequate to ensure a controlled depressurisation of the system.

12.2.2

Means shall be provided to prevent any pressurized storage vessel from being isolated from a pressure relief device. This may be achieved by the removal of isolation valve handle and the adoption of formal procedures to take vessels in and out of service.

12.2.3

Any pressure relief device shall be of a design such that:

• • • •

when activated, it shall be able to keep the pressure not exceeding 1.1 times the MOP if adjustable, it can be sealed in the set position in order to prevent unauthorized adjustment it is marked with the set pressure and, where appropriate, the direction of flow it discharges to a safe termination point as per Sub-Section 7.9 of this Standard.

12.2.4

When using steel pressure vessels, a suitable relief device that releases the pressure at a temperature of 100°C ± 10°C should be fitted to each manifolded group of vessels, in order to permit controlled discharge in the event of fire.

12.2.5

Where pressure vessels made from materials other than steel are used, documentation shall be provided, indicating that the relief device will operate before failure of the material due to high temperatures in case of fire.

12.2.6

The location and direction of temperature relieving devices shall be part of the HAZOP.

12.3

EMERGENCY ISOLATION VALVE

An automatic emergency isolation valve shall be fitted on the outlet from any storage facility. A manual valve may be useful for maintenance purposes.

12.4

PRESSURE GAUGE At least one pressure gauge shall be fitted to the storage facility. The pressure gauge shall be capable of reading a pressure level of at least 1.2 times the MOP. 30 ©IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk.


12.5

CONTROL SYSTEMS

Systems to control the pressure levels in different storage banks (e.g. cascade systems) shall be fit for purpose and shall not adversely affect the safety systems of the storage facility.



SECTION 13 : STATION PIPEWORK AND ANCILLARY DEVICES 13.1

GENERAL PROVISIONS

13.1.1

Pipework and fittings shall be suitably secured to prevent disconnection during normal operation.

13.1.2

Where components are placed on different foundations, which could move separately, consideration shall be given to using appropriate flexible connections. In all other situations, the use of flexible connections shall be limited and subjected to an appropriate risk assessment.

13.1.3

The design of the pipework shall consider stress analysis.

13.1.4

The number of mechanical joints shall be kept to a minimum.

13.1.5

Pipework shall be located in a location where it cannot be damaged by moving vehicles, or suitable protection shall be provided.

13.1.6

Prior to pressure testing, all welds shall be subjected to non destructive testing. (See Section 16).

13.1.7

Pipework shall be inspected on a regular basis. This shall be defined in the operation and maintenance procedure as described in Appendix 8.

13.1.8

All operational valves shall be labelled with identification tags, which will be displayed on the P&ID diagram.

13.1.9

The P&ID diagram shall be available for operational use.

13.2

INLET SUPPLY PIPEWORK The following applies to pipework upstream of the compressor(s):

13.2.1

The pressure of the inlet pipework will depend upon the source. It may be low pressure if supplied from the distribution system, but could be up to 300 bar if supplied from a mobile storage unit. The Standard used shall be suitable for the pressure level.

13.2.2

The inlet pipework shall be in accordance with one of the following Standards: EN 15001-1, EN 13480 (parts 1-6).

13.2.3

The inlet pipework may be above or below ground (may be buried).

13.2.4

All inlet pipework shall be constructed of appropriate corrosion protected steel or stainless steel pipe.

13.2.5

For mobile supply, the design and operation of the connection system shall permit safe and secure connection and disconnection. The connection point shall be securely sealed when not connected to a supply source.

13.2.6

Above ground inlet pipework

13.2.6.1

The above ground pipework section shall be restricted from unauthorised access.



13.2.7

Buried inlet pipework

13.2.7.1

All buried pipework joints shall be welded.

13.2.7.2

Buried pipework shall be inspected for leakage on a regular basis.

13.2.7.3

Carbon steel pipework shall be suitably protected by an anti-corrosion system.

13.2.7.4

Where the piping is cathodically protected or other considerations call for it, insulated connections shall be fitted to electrically isolate fuelling devices from gas pipework.

13.2.7.5

Insulated connections installed above ground in hazardous areas shall be adequately separated to avoid sparking.

13.2.7.6

When installing insulated connections outside the covered area of the fuelling station, the section of underground piping, including the insulation joint(s), shall be externally wrapped.

13.2.7.7

Underground piping shall be marked by means of laying a warning tape above it during construction.

13.2.8

Inlet pipework in ducts

13.2.8.1

Where pipework is installed in below ground ducts, effective ventilation and drainage shall be provided. All pipework joints shall be welded and the pipework shall be constructed of an appropriate grade of carbon steel or stainless steel.

13.2.8.2

The ducts shall be accessible for visual inspection of the pipework.

13.2.8.3

The construction and quality of the pipework shall be the same as for above ground pipework.

13.2.8.4

Pipework shall be located in a duct or void only if the duct or void is adequately ventilated.

13.3

OUTLET PIPEWORK

13.3.1

The outlet pipework shall comply with BS EN 13480 (parts 1-6) as appropriate.

13.3.2

Above ground outlet pipework.

13.3.2.1

All above ground pipework shall be constructed of carbon steel appropriately corrosion protected or stainless steel pipe.

13.3.2.2

If possible, above ground pipework should not be used for vehicle accessed areas. If above ground pipework is used, it shall be so located and protected to avoid damage from high vehicles.

13.3.3

Below ground level outlet pipework

13.3.3.1

Pipework installed below ground level shall be installed within ducts in accordance with Sub-Section 13.3.3.3 of this Standard or in below ground casing as defined in Sub-Section 13.3.3.4.



13.3.3.2

Pipework may be installed in pits containing below ground storage (see Appendix 10).

13.3.3.3

Outlet pipework in ducts

13.3.3.3.1

Ducts shall be specially provided for CNG use. The ducts shall only contain CNG pipework and if necessary, drainage water line, compressed air line and suitably insulated single phase power lines and communication cables. CNG pipework shall be separated from other pipe lines.

13.3.3.3.2

The ducts and its covers shall be constructed to withstand vehicle loading.

13.3.3.3.3

The ducts shall have adequate drainage.

13.3.3.3.4

CNG pipework shall be adequately supported and raised above the bottom of the duct.

13.3.3.3.5

All pipework joints in ducts should be welded. Where mechanical joints are fitted due regard shall be taken of ventilation requirements and hazardous area implications in and around the duct if it has a ventilated cover. Mechanical joints shall be accessible for inspection and leakage detection.

13.3.3.3.6

The ducts shall be easily accessible for visual inspection of the pipework.

13.3.3.3.7

The duct shall be adequately ventilated.

13.3.3.4

Outlet piping in sleeves

13.3.3.4.1

Pipework shall not be installed in unventilated sleeves.

13.3.3.4.2

Pipework periodical inspection shall be specified in the operational and maintenance procedures.

13.4

FLEXIBLE CONNECTIONS

Any flexible connection shall be suitable for the design parameters. For dispenser filling hoses, see Sub-Section 14.3. 13.5

PRESSURE GAUGES

13.5.1

Where appropriate, adequate monitoring devices, e.g. pressure gauges shall be installed to enable adequate action to be taken either automatically or manually to keep the pressure equipment within the allowable limits. All gauges shall have a full scale reading of at least 1.2 times the MOP. Suitable pressure transducers may be used.

13.5.2

All pressure gauges throughout the fuelling station, storage facilities and dispenser shall have the same units.

13.6

PRESSURE TESTING

The complete installation shall be suitably tested for strength and tightness using an approved method.



SECTION 14: DISPENSER 14.1

GENERAL PROVISIONS

14.1.1

The location shall be in a well ventilated location, preferably in the open air. If not located in the open air, the location shall be subjected to risk analysis.

14.1.2

The location shall be in the open air for public accessed fuelling stations.

14.1.3

Vehicles shall be allowed to enter the hazardous area only around the dispenser to be fuelled.

14.1.4

After return of power either deliberately or automatically the dispenser will not permit gas flow until a specific attendant or user action has been performed.

14.2

DISPENSING UNIT

14.2.1

Gas shall only be dispensed using equipment with the following safety devices:

• • •

the Breakaway device shall comply with ANSI/IAS NGV 4.4 the disconnection force of the breakaway device shall be lower than 500 N for dispensers for personal vehicles and 850 N for high flow dispensers for commercial vehicles, in any direction an automatic system shall be installed for each fuelling hose to shut off the gas flow if a pressure level of 250 bar at +15°C in the vehicle gas tank is reached or when the fuelling process has ended.

14.2.2

The dispensing unit shall be protected against vehicle collision. In case of damage to the dispenser (despite the collision protector), an automatic valve or a flow limiting system shall be activated closing the supply to the dispenser at its inlet. The response shall be less than five seconds. The flow limiting device shall actuate when flow exceeds 10% of the maximum expected flow during normal operation.

14.2.3

When connected to the vehicle, the vehicle and dispensing equipment shall be equipotential.

14.2.4

For public fast-fill self-service fuelling stations, the dispensing unit shall be equipped with a button or handle, such that after connecting the nozzle to the vehicle, the refuelling will only start when this button or handle is manually operated.

14.2.5

Suitable calibrated metering systems shall be required for public fuelling dispensers according to the 'weights and measures' requirements for the sale of goods.

14.2.6

Dispensers shall be lockable or have other provisions for preventing their use when the site is unmanned.

14.2.7

The dispensing nozzle shall comply with ANSI/IAS NGV 4.1

14.3

FILLING HOSE

14.3.1

The filling hose shall be flexible and resistant to corrosion and mechanical damage. It shall be adequately supported or coated to prevent kinking and abrasion.



14.3.2

The hose shall be suitable for CNG under normal operating conditions.

14.3.3

The length of the filling hose assembly shall be the minimum required. It shall, not be less than 3 metres or exceed 5 metres or however.

14.3.4

The dispenser should provide facility for safe stowage of the delivery hose when not in use.

14.3.5

The filling hose shall have a burst pressure of at least four times the MOP. The hose shall have been subjected to a strength test of at least twice the MOP and the test report shall be available.

14.3.6

The hose shall be continuously marked with the MOP, date of production and the manufacturer's name or trademark, applicable service. The hose shall be inspected regularly and replaced at specified intervals according to the manufacturer's instructions.

14.3.7

The hose connections shall withstand a force in the linear direction 20% greater than the force required to operate the break-away device (see Sub-Section 14.2.1) and the hose's burst pressure. The manufacturer’s instructions for the breakaway device shall be followed for installation, operation and maintenance.

14.3.8

The filling hose shall comply with ANSI/IAS NGV 4.2

14.4

FILLING NOZZLE

14.4.1

The filling nozzle shall permit the flow of gas if there is an adequate connection between the nozzle and the receptacle device on the vehicle. The connection shall prevent the escape of gas when it is not fully engaged or becomes separated.

14.4.2

The nozzle shall comply with the requirements of ISO 14469 (part 1 or 2) and shall match the receptacle of any vehicle complying with ISO 15501-1 and ISO 15501-2. The nozzle shall be suitable for the intended mode of use – self service/fast fill/slow fill. Adaptors and other types of connection fittings shall not be used.

14.4.3

When the filling nozzle is not in use, it shall be stored in a manner to prevent entry of moisture and debris.

14.5

CAPTIVE VENT SYSTEMS

Where nozzle designs incorporate a system to collect the small releases of gas on connection/disconnection, they shall be vented to a safe area.



14.6

FILLING MOBILE STORAGE UNITS Where a facility is provided to fill mobile storage units, the following shall apply:

• • • • •

a suitably designed self-sealing filling connection system shall be provided and a break away device shall be installed a suitable system for grounding the trailer during filling shall be used filling shall only be undertaken by suitably trained operatives a suitable control system shall prevent overfilling of the mobile storage the filling operation shall be attended or left in a safe and secure manner to prevent interference.



SECTION 15 : ELECTRICAL EQUIPMENT AND WIRING 15.1

15.2

GENERAL Where the equipment is placed in a hazardous area, it shall comply with the appropriate zoning rating as required in BS EN 60079-10-1. EARTHING AND BONDING PROTECTION

15.2.1

All electrical equipment, metal frames and structures that are within hazardous zones shall be grounded and bonded.

15.2.2

Means to ground tube trailers and transportable modules prior to flexible hose connection shall be provided.

15.3

LIGHTNING PROTECTION

Measures for protection against lightning shall comply with the requirements in IGEM/UP/2.



SECTION 16 : TESTING, PURGING AND COMMISSIONING 16.1

TESTING AND PURGING

16.1.1

All pressure loaded equipment shall be suitably tested for strength and tightness and adequately purged before use.

16.1.2

The proposed design of the pipework system shall be checked to see if adequate provision has been made to permit safe and effective testing and purging to be undertaken. All on-site strength testing shall be undertaken hydrostatically. Specialist drying shall be undertaken to ensure all water is removed.

16.1.3

Consideration shall be given to the safety of all persons during strength testing, whether or not involved in the testing.

16.1.4

The compressor and other components may need to be excluded from on-site testing and purging according to the manufacturer's instructions.

16.1.5

Documentation of all tests, on and off-site, and purges shall be provided.

16.1.6

Consideration shall be given to the environmental impact of releasing natural gas into the atmosphere during purging operations and flaring may be preferable.

16.1.7

All testing and purging shall be performed by a competent person.

16.1.8

Testing and purging of any LNG storage facility shall only be undertaken by specialist organisations.

16.2

COMMISSIONING

16.2.1

Upstream of the compression unit, consideration shall be given to installing a temporary start-up (commissioning) filter.

16.2.2

Commissioning of all station components and proper operation of all safety equipment shall be undertaken by a competent person and documented.

16.2.3

Commissioning of any LNG storage facility shall only be undertaken by specialist organisations.



SECTION 17 : SIGNS, MARKINGS, AND INSTRUCTIONS 17.1

GENERAL

17.1.1

All equipment markings and literature of a CNG fuelling station should be in English.

17.1.2

Signs shall be printed in English and shall include the relevant pictograms.

17.1.3

Hazardous Area warning signs shall clearly mark the area which is classified as a hazardous area indicating that smoking, naked lights and the use of unprotected electrical equipment are prohibited.

17.1.4

Restricted areas shall be marked accordingly, including those areas requiring special safety equipment (PPE etc) to be worn.

17.2

MARKING Fuelling station components shall carry the markings in a durable, legible manner on a firmly attached data plate that includes (where applicable) the following:

• • • • • • 17.3

identification of the manufacturer and, where appropriate, identification of his authorized representative year of manufacture unique identification of the station, such as type, series or batch identification and/or serial number essential limits such as MOP and temperature operating pressure rated power in kVA and supply voltage in V.

DISPENSER SIGNS

17.3.1

The dispenser shall be clearly labelled, indicating that it dispenses "CNG". Dispensers intended differing dispensing pressures shall be suitably labelled. The maximum dispensing pressure shall be indicated.

17.3.2

Warning signs shall indicate that engines and lights should be turned off and that smoking, naked lights, re-entering the car while refuelling and use of cellular telephones are prohibited.

17.3.3

An emergency telephone number shall be displayed.

17.4

FUELLING INSTRUCTION SIGNS For self-service fuelling stations, the fuelling instructions shall be clearly displayed at dispensing units adjacent to each filling hose. For other filling stations, the instructions shall be easily accessible for the personnel.



SECTION 18 : PROCEDURES 18.1

INSTRUCTION OF EMPLOYEES The fuelling station operators and staff shall be suitably trained in the operation of equipment and in the emergency procedures. See Appendix 8.

18.2

INSTALLATION, COMMISSIONING AND OPERATING PROCEDURES

18.2.1

Installation, commissioning and operating procedures and instructions for the station shall be provided. They shall include at least the following:

• • • • • • • • •

mounting, including assembling of different pieces of pressure equipment, if any how to put the station into service its proper operation minimum requirements for maintenance including inspection by the operator such as visual inspection of the filling hose and nozzle compressor operator checks e.g. condensate drain, etc the need to have the station periodically inspected in a manner and frequency specified by local regulations the need to replace the hose at prescribed intervals all information given in Sub-Section 17.2 except the serial number hazardous area classification information and separation distances.

18.2.2

Where appropriate, technical documents, drawings and diagrams should be included for a full understanding of the instructions.

18.2.3

Where pipework is installed below ground (including ducts), the positioning and the routing of the below ground pipework shall be included in the instructions.

18.3

POTENTIAL HAZARDS

18.3.1

All potential hazards shall be considered (see Sub-Section 7.1) and included in the installation, commissioning and operating procedures and instructions. Respective warning signs shall be displayed accordingly (e.g. high pressure, high voltage).

18.3.2

Consideration shall be given to the CNG cooling effect which will occur when the system is depressurised.

18.4

EMERGENCY PROCEDURES

18.4.1

Emergency procedures for the fuelling station shall be produced.

18.4.2

An emergency plan shall be set up for the CNG fuelling station. This shall be included in the emergency procedures.



SECTION 19 : EMERGENCY SHUTDOWN PROCEDURES 19.1

An emergency shutdown procedure shall be provided to shut down the fuelling station safely and isolate the gas inlet in an emergency or in a case of a power failure. This shall be incorporated into the operational safety management system for the fuelling station.

19.2

The procedure shall include a compressor shutdown and isolation of any storage facility outlet by the operation of automatic valves and a restart procedure after shutdown. For example, an emergency shutdown procedure could be as follows:

•

the fuelling station power supply shall be isolated except power for safety, control and ventilation systems

• •

the gas supply to the dispenser fuelling hose(s) shall be isolated

•

the main isolation valve to the fuelling station shall be automatically closed during emergency shutdown.

Note:

the gas flow between the compressor, storage, and dispensing unit and also between storage sections shall be stopped. If more than one dispensing unit is connected to the storage, the delivery may be stopped with common valves

Automatic depressurisation needs to be avoided during emergency shutdown.

19.3

The emergency shutdown procedures shall be initiated by the activation of manual emergency buttons, detection of high gas concentration, smoke detection, fire detection, odorant equipment failure or other hazardous situation detection devices

19.4

Emergency shutdown activation devices (e.g. ‘ESD’ buttons) shall be suitably located throughout the fuelling station:

• • • 19.5

a minimum of one button on each dispenser one on the control panel one on the compressor control panel at least one additional accessible button shall be located between 5 and 40 m from the dispenser

The types of ESD button available are:

•

STOP BUTTON

A red coloured non-latching push to activate button that causes dispensing or other functions to Stop. It may not remove power but will require a manual operation to restart the equipment.

•

EMERGENCY STOP BUTTON

A non-latching red coloured push to activate button that isolates the equipment in use from power and so causes all function, except safety systems, to stop. A manual operation shall be required to restore power and further manual operations to re-start the equipment.



•

LATCHING EMERGENCY STOP BUTTON

Operation as for a non-latching type but additional action required to release the button from the depressed condition.

•

FIREMAN’S SWITCH

A red coloured lever operated isolation switch that removes all power from the site except essential safety equipment. Moving the lever back to the on state requires one or more additional actions to restore power to equipment (typically contactors with Start switches).

•

START BUTTON

A green coloured push button that is connected to a control system or a green coloured push button that causes a contactor to close and restore power. 19.6

These requirement demand special attention for self-service stations, in order to avoid interference and mishandling.

19.7

A reliable power supply source shall be used to operate components that are essential for safety.

19.8

A restart procedure shall be provided which will require manual restart by a suitably trained person.



APPENDIX 1 : GLOSSARY, ACRONYMS ABBREVIATIONS, UNITS GLOSSARY Other definitions are provided in IGEM/G/4 which is freely available by downloading a printable version from IGEM’s website www.igem.org.uk. Recommended and legacy gas metering arrangements are given in IGEM/G/1 which is freely available by downloading a printable version from IGEM’s website www.igem.org.uk. biomethane

gas comprising principally methane, obtained from either upgrading of biogas or methanation of bio-syngas.

break-away device

device which, when activated, stops gas flow from the dispenser (for example if the vehicle moves away while still connected to the refuelling hose).

burst pressure

the pressure which causes failure and consequential fluid loss through the component envelope.

canopy

roof, for example a shelter, a hood etc., which affords a degree of weather protection.

cascade dispensing sequence

means of allowing efficient use of the gas storage facility by dividing it into banks operating at different pressure levels.

compression unit

a unit that compresses the natural gas consisting of one or more compressors, including all associated piping and ancillaries.

compressor

a machine which increases the pressure of gas from a low to a higher level.

CNG filling/fuelling area

a location at which CNG is dispensed into a vehicle or to a mobile CNG storage.

CNG fuelling station inlet isolation valve

connection point to the supplier.

cylinder

any pressure vessel used for the storage of compressed natural gas.

delivery pressure

the pressure at which the gas is delivered to the vehicle.

dispenser

the equipment through which the compressed natural gas is supplied to the vehicle.

dryer

system which decreases the water content of the natural gas.

fast fill

filling operation which is comparable in duration to that of liquid fuel.

fire wall

wall, screen or separating partition erected in the open air to reduce the effects from radiated heat and to ensure



an adequate dispersion distance for CNG leaking from any vessel. gas conditioning equipment

equipment to filter and/or remove unwanted constituents (moisture, debris, liquid and vapours) from the gas either prior to or after compression.

inlet supply pipework

the pipework section upstream of the compressor.

liquid separator

device which causes any liquids within the gas to drop out of suspension for collection and can be located after compression of the Natural Gas

mobile CNG storage unit

pressure vessel (Multi-Element Gas Container [MEGC] or battery vehicle [tube trailer]) used for the transportation of CNG to other fuelling stations.

Mother station

station filling CNG mobile storage

Daughter station

station being supplied by CNG mobile storage

open building

construction, in which the same ventilation conditions are present as in the open air and no obstruction for natural air circulation is present.

outlet pipework

the pipework section downstream of the compressor.

overpressure

pressure above the maximum operational pressure.

recovery vessel

vessel that recovers gas from the compressor and its ancillaries and which may also serve to damp out pressure pulsations in the compressor inlet.

safety distance

the separation distance between the fuelling station, its components and structures and other installations and structures in the vicinity for protecting people and property and reducing the degree of danger in the case of an incident.

station owner/operator

the person who owns, or is responsible for the operation of the fuelling station.

storage

any number of suitable compressed natural gas storage containers designed for the purpose of containing and subsequently releasing compressed Natural Gas.

test pressure (TP)

The pressure to which the installation or part of installation, is tested. Different levels may be required for storage pressure vessels and other components.

Timed-fill

filling operation which is not a fast fill (see also fast fill definition) and typically takes several hours.

vehicle refuelling appliance (VRA)

self-contained system that compresses natural gas and dispenses the gas to a single vehicle fuel system via slow fill.



GLOSSARY, ACRONYMS, ABBREVIATIONS AND UNITS ACoPs BCGA BP CNG EU FMEA GB HAZID HAZOP HSE IGEM LNG MOP NG NGV P&ID UK UKAS VRA

Approved Codes of Practice British Compressed Gases Association burst pressure Compressed Natural Gas European Union Failure Mode and Effects Analysis Great Britain Hazard Identification Hazard and Operability Analysis Health & Safety Executive Institution of Gas Engineers & Managers Liquified Natural Gas maximum operating pressure Natural Gas Natural Gas Vehicle Piping and Instrumentation Diagram United Kingdom United Kingdom Accreditation Service vehicle refuelling appliance.

SYMBOLS %

percentage.

UNITS dB kW kVA l m mm mm2 N V °C

decibel kilowatt kilovolt-ampere litre metre millimetre square millimetre newton voltage degree Celsius.



APPENDIX 2 : REFERENCES This Standard is set out against a background of legislation in force in the UK at the time of publication. Similar considerations are likely to apply in other countries and reference to the appropriate national legislation will be necessary. This Appendix lists legislation, guidance notes and Standards etc. which are identified within this Standard as well as further items of legislation which may be applicable. Where British Standards are quoted, equivalent national or international Standards, etc. equally may be appropriate. Unless otherwise stated, the latest version of the referenced document should be used. A2.1

LEGISLATION • Asbestos (Prohibition) Regulations 1992 • Building (Amendment) Regulations (Northern Ireland) 2006 • Building Regulations for England and Wales 2002 • Building Standards (Scotland) Regulations 1990 • Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations 2009 • Confined Spaces Regulations 1997 • Construction (Design and Management) Regulations 2007 • Control of Asbestos Regulations 2006 • Control of Major Accident Hazard Regulations 2005 • Control of Noise at Work Regulations 2006 • Control of Substances Hazardous to Health Regulations 2002 • Dangerous Substances and Explosive Atmospheres Regulations 2002 • Electricity at Work Regulations 1989 • Gas Act 1986 as amended 1995 • Gas Appliances (Safety) Regulations 1995 • Gas Cooking Appliances (Safety) Regulations 1995 • Gas Safety (Installation and Use) Regulations 1998 • Gas Safety (Management) Regulations 1996 • Health and Safety at Work etc. Act 1974 • Health and Safety (Safety Signs and Signals) Regulations 1996 • Heating Appliances (Fireguards) Regulations 1991 • Management of Health and Safety at Work Regulations 1999 • Pressure Equipment Regulations 1999 • Pressure Systems Safety Regulations 2000 • Provision and Use of Work Equipment Regulations 1992 • Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 1995 • Regulations Concerning the International Carriage of Dangerous Goods by Rail • Supply of Machinery (Safety) Regulations 2008 • Workplace (Health, Safety and Welfare) Regulations 1992.

A2.2

INTERNATIONAL STANDARDS • ISO 4126-1 Safety devices for protection against excessive pressure – Part 1: Safety valves 47 ©IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk.


• • • • • • • •

ISO 14120

Safety of machinery - Guards - General requirements for the design and construction of fixed and movable guards ISO 14469-1 Road vehicles - Compressed natural gas refuelling connector – Part 1: 200 bar ISO 14469-2 Road vehicles - Compressed natural gas refuelling connector – Part 2: 200 bar size 2 ISO 15501-1 Road vehicles – Compressed natural gas (CNG) fuel systems – Part 1: Safety requirements ISO 15501-2 Road vehicles – Compressed natural gas (CNG) fuel systems – Part 2: Test methods ISO 15609-1 Specification and approval of welding procedures for metallic materials – Welding procedure specification - Part 1: Arc welding ISO 15609-2 Specification and qualification of welding procedures for metallic materials – Welding procedure specification Part 2: Gas welding IEC 60079-29 Gas detectors – Performance requirements of detectors for flammable gases.

A2.3

EUROPEAN STANDARDS • EN 287-1 Qualification test of welders - Fusion welding - Part 1: Steels • EN 437 Tests gases. Test pressures. Appliance categories • EN 473 Non-destructive testing - Qualification and certification of NDT personnel – General principles • EN 5429 • EN 1964 Transportable gas cylinders • EN 1012-1 Compressors and vacuum pumps; Safety requirements – Part 1: Compressors • EN 10204 Metallic products – Types of inspection documents • EN 15001-1 Gas infrastructure. Gas installation pipework • EN 15001-2 Gas infrastructure. Gas installation pipework • EN 13445-1 Unfired pressure vessels - Part 1: General • EN 13445-2 Unfired pressure vessels - Part 2: Materials • EN 13458-3 Cryogenic vessels. Static vacuum insulated vessels • EN 13480-1 Metallic industrial piping - Part 1: General • EN 13480-2 Metallic industrial piping - Part 2: Materials • EN 13480-3 Metallic industrial piping - Part 3: Design and calculation • EN 13480-4 Metallic industrial piping - Part 4: Fabrication and installation • EN 13480-5 Metallic industrial piping - Part 5: Inspection and testing • EN 13480-6 Metallic industrial piping - Part 6: Additional requirements for buried piping • EN 60079-10-1 Explosive atmospheres. Classification of areas. Explosive gas atmospheres.

A2.4

NATIONAL INDUSTRY STANDARDS • IGEM/UP/5 Edition 2 Part 2 (in development)

•

IGE/UP/5 Part 3 – Natural Gas Vehicles: Filling Station Operations

•

IGEM/UP/6 Edition 2 – Application of compressors to Natural Gas fuel systems IGE/GL/8 Edition 2 – Reporting and investigation of gas-related incidents ASME B31.3 – Process piping ASME VIII-1 – Boiler and Pressure Vessel Code - Rules for Construction of Pressure Vessels

• • •



• • • A2.5

ANSI/IAS NGV 4.1 - Dispensing Systems ANSI/IAS NGV 4.2 – Hoses for NGV and Dispensing System ANSI/IAS NGV 4.3 – Breakaway Devices for Natural Gas Dispensing System and Hoses.

OTHER LEGISLATION Directive 97/23/EC of the European Parliament and of the Council of 29 May 1997 on the approximation of the laws of the Member States concerning pressure equipment

•

A2.6

•

Directive 2006/42/EC – The Approximation of the Laws of the Member States Relating to Machinery

•

Directive 97/23/EC – Pressure Equipment Directive.

OTHER STANDARDS AND PUBLICATIONS • BCGA CP36 • BS 5429 • BS 5499 Part 5 • BS 6399 Part 2 • Cryogenic Safety Manual (British Cryoengineering Society) • HSL56 Guidance Notes 22, 28, 29 • HSR25 • HSL 122 • HSL134 • HSL135 • HSL136 • HSL137 • HSL138 • HSL 144 • INDG 178 • INDG 261 • INDG 291 • INDG 229 • INDG 370 • SI 3864 Part 1.



APPENDIX 3 : HAZARDOUS AREA ZONES Hazardous areas dimensions examples are shown in the below table.

Hazardous areas - Installed Equipment Where equipment has been Ex certified by a European Notified Body then the certified hazard zones created by that equipment may be used for risk management and site design purposes but without this qualification, the hazard zone here shall be used by default.

Equipment

Dispensers Compressors

Zone 2

1 m radius from all openings 1 m radius from all openings

Zone 1

None None Includes connections within control system.

Cylinder connections.

5 m radius from connections

None

Vents

15 m vertical cone of 60 °

3 m radius from vent

Note:

Notes Hose, nozzle and vehicle are not included.

Includes Service blowdown.

Equipment and site specific Hazardous area calculations will have to be undertaken to define actual dimensions.



APPENDIX 4 : SEPARATION DISTANCES The following table shows internal separation distances related to a CNG fuelling station optional types. The layouts shown below are informative and may differ according to design.

Separation Distances - Installed equipment Hazard source

Separation distances Buildings Canopies & over structures Public access ways Facility perimeter Roads and footpaths Storage of other fuel types Service Access Combustible materials

Dispenser incl. vehicle filling point

Storage cylinders including gas delivery trailers

Compressor

Vents normal use & relief valves.

A

B

C

D

>4m

>4m

>4m

>4m

not above

not above

not above

not above

NA

>5m

>2m

>5m

>4m

>2m

>2m

>5m

>4m

>3m

>3m

>5m

>5m

>5m

>5m

>2m

>3m

na

>4m

>4m

>4m

>4m unless certified for both >2m >4m



APPENDIX 5 : EXAMPLE OF TYPICAL CNG FUELLING STATION COMPONENTS



APPENDIX 6 : FUELLING STATION



APPENDIX 7 : GENERAL SAFETY CONSIDERATIONS FOR LNG STORAGE FACILITIES A7.1

CRYOGENIC BURNS Severe damage to the skin may be caused by contact with LNG or with uninsulated pipes or receptacles containing LNG. For this reason, gloves and eye protection shall be worn when handling equipment containing LNG. All the safety aspects of handling LNG cannot be covered adequately in this Standard. The reader is therefore referred to the British Cryoengineering Society’s ‘Cryogenic Safety Manual’ for further information.

A7.2

AIR CONDENSATION Ambient air may condense on uninsulated pipes and vessels containing LNG causing local oxygen enrichment of the atmosphere. Appropriate insulating materials shall be chosen considering oxygen enrichment may occur.

A7.3

EMBRITTLEMENT OF MATERIALS Many materials, such as some carbon steels and plastics, are brittle at very low temperatures and appropriate material shall be selected for the service conditions. Note:

A7.4

Metals suitable for LNG service include 9% nickel steel, 18/8 stainless steel and other austenitic stainless steels, copper and its alloys and aluminium alloys. PTFE (polytetrafluoroethylene) is the most widely used plastic materialfor sealing purposes in cryogenic service but other reinforced plastics are also used. For further information on materials see BS 5429.

FIRE PRECAUTIONS The storage of cryogenic liquids shall be considered in the site fire risk assessment. Flammable substances and combustible materials shall not be stored or allowed to accumulate in the vicinity of cryogenic liquid installations.

A7.5

IGNITION SOURCES Smoking and open fires shall be prohibited within the minimum distances specified in Appendix 4.

A7.6

LAYOUT AND DESIGN FEATURES

A7.6.1

General The LNG installation shall be sited to minimise risk to personnel, local population and property. Consideration shall be given to the location of any potentially hazardous processes in the vicinity, which could jeopardise the integrity of the storage installation. An installation may, because of its size or strategic location, come within the scope of specific planning controls. If so, the siting of any proposed installation shall be discussed and agreed with the local authority and appropriate sections of the Health and Safety Executive.

A7.6.2

Design and manufacture of the tank 54 ©IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk.


LNG tanks and associated equipment shall be designed, manufactured and installed in accordance with recognised pressure vessel, storage tank and piping codes that meet the requirements of the Pressure Equipment Regulations 1999. Where appropriate, tanks shall be designed to withstand wind loads in accordance with the appropriate design codes e.g. BS 6399 Part 2. A7.6.3

Materials All components shall be constructed from materials compatible with LNG, and with the temperature and pressure conditions to which they will be subjected. These considerations shall be also taken into account when designing pipework systems and their accessories connected to the tank, for example fill, product withdrawal and vent lines.

A7.6.4

Tank pressure relief devices Each LNG tank shall have pressure relief devices on both the inner vessel and outer jacket. Inner vessels shall be protected by at least two independent safety devices. Typically, a pressure relief valve and a separate bursting disc is fitted. Combinations of smaller capacity relief valves can be used to achieve the required rate of relief. Safety relief systems should comply with BS EN 13648. For sizing the relieving capacity of pressure relief devices all operational conditions shall be considered including:

• • • •

boil off rate (including a safety factor) in case of insufficient insulation due to loss of vacuum flash gas from filling operations of road tankers malfunction of control valves in pressure raising systems; or any other foreseeable source of energy input into the vessel i.e. fire, pump recycle systems.

A7.6.4.1

Consideration shall be given to the provision of secondary relief devices, such as bursting discs, depending on the degree of risk associated with the installation and prevailing climatic or environmental conditions, e.g. icing due to high humidity, corrosion etc.

A7.6.4.2

At least one online pressure relief valve (or combination of small relief valves) shall have a capacity and set-point that will prevent the pressure within the vessel exceeding the maximum allowable working pressure in accordance with the applicable vessel design code. The combined capacity of all online relief devices shall be sufficient to prevent the test pressure of the tank being exceeded, in the event of loss of vacuum combined with the pressure-build up system failing in the open position.

A7.6.4.3

It shall not be possible to isolate a combination of relief devices which could result in a reduced relieving capacity.

A7.6.4.4

If a three-way valve is installed to accommodate two pressure relief devices operating either simultaneously or alternatively, then the size of the three-way valve and the inlet pipework shall be such that the vessel is always adequately protected.



A7.6.4.5

If the outlet of a relief valve is connected to any pipework, nozzle, elbow or relief valve header, any imposed back pressure shall be included in the relief valve sizing calculation.

A7.6.4.6

The relieving devices shall be designed to operate effectively across the full range of working temperatures.

A7.6.4.7

All pressure relief devices shall be orientated in such a manner as to prevent the accumulation of water or other contamination, which could result in incorrect operation.

A7.6.4.8

Installation and orientation of the relief device shall be in accordance with manufacturers recommendations. Consideration shall be given to the thrust resulting from operation of the relief device and the affect on the device,pipework and vessel nozzle. Provision of additional supports may be required to control imposed thrust forces.

A7.6.4.9

Due consideration shall be given to the direction of any relief device vent so that it does not affect the safety of personnel or equipment. Consideration shall also be given to the ease of access to the three way change over valves for operation when a relief device is discharging.

A7.6.4.10

Outer jackets need not be designed to a pressure vessel design standard, but they shall be capable of withstanding full vacuum. Outer jackets shall be fitted with a device to relieve pressure increase in the event of a leak from the inner vessel. The device shall be set to open at a pressure of not more than 0.5 bar. The discharge area of the pressure relief device shall be not less than 0.34 mm2 per litre capacity of the inner vessel but not less than 10 mm diameter.

A7.6.5

Markings The tank shall be marked in accordance with the requirements set out in paragraph 3.3 of schedule 2 of PER. The safe operating limits should be readily accessible

A7.6.6

Safety distances Safety distances are defined as the distance from the exposure or item to be protected to the nearest of the following: a) any point on the storage system where in normal operation leakage or spillage can occur (e.g. hose couplings, including those on extended fill lines, relief valve vents, etc), or b) the tank outer jacket, or c) the tank nozzles, Safety distances are intended to: a) protect personnel from exposure to hazardous atmospheres and to prevent fire enhancement in the event of a release of liquid oxygen b) protect the installation from the effects of thermal radiation or jet flame impingement from fire hazards.



A7.6.7

Location of the installation Consideration shall be given to the consequences of any liquid spillage from the tank and resultant vapour clouds when choosing a location for the tank. When gas is not being withdrawn, pressure within the tank will gradually increase to the point where the relief valve will lift. Although the rate of gas discharge is small, precautions shall be taken to avoid the build up of dangerous atmospheres. Storage installations should be situated in the open air in a well-ventilated position and where there is no risk of damage by passing vehicles. Storage tanks should be at the same level as the tanker parking area to enable the operator/driver to control the transfer operations.

A7.6.8

Installation level and slope Where liquid cryogenic storage tanks are required to be installed at an elevated level, they shall be supported by purpose designed structures which should withstand or be protected from damage by cryogenic liquid spillage. The slope of the ground shall be such as to allow surface water run off.

A7.6.9

Position of gas vents Vents, including those of safety relief devices, shall vent to a safe place in the open and comply with the safety distances shown in Appendix 3. They shall be directed so as not to impinge on personnel, occupied buildings and structural steelwork. Consideration shall be given to the prevention of accumulation of water, including that from condensation, in vent outlets. All vent systems shall be adequately supported to cope with loads created during discharge.

A7.6.10

Liquid transfer area The liquid transfer area should be designated a ‘No Parking’ area and should be level. A road tanker, when in position for filling from or discharging to the installation, shall be in the open air and not be in a walled enclosure from which the escape of liquid or heavy vapour is restricted. Tankers should have easy access to and from the installation at all times. The installation shall be protected from vehicular damage that could result in product release. The liquid transfer area should normally be located adjacent to the fill coupling of the installation and be positioned in such a way that it facilitates the movement of the tanker in the case of an emergency. Extended fill lines should be avoided if possible. Unless the tank is specifically designed for remote filling, suitable ‘repeater’ gauges and valves should be installed at the extended fill point. The length of extended filling lines should be kept to a minimum. Transfer of liquid with the tanker standing on public property is not recommended. However, if this cannot be avoided, the hazard area shall be clearly defined, using suitable notices during the transfer period. Access to this area during transfer shall be strictly controlled. 57 ©IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk.


A7.6.11

Isolation valves Any primary process isolation valve shall be located as close as practical to the vessel itself and be easily accessible. Protection against over pressure shall be installed between any two isolation valves where liquid or cold vapour can be trapped and the position of isolation valves should be such that they can be afforded adequate protection against damage from external sources.

A7.6.12

Secondary isolation valves A secondary means of isolation should be provided for those lines greater than 9 mm nominal bore and:

• •

Emanating from below the normal liquid level and Having only one means of isolation between tank and atmosphere (such as liquid filling lines), to prevent any large spillage of liquid should the primary isolating valve fail.

The secondary means of isolation, where provided, may be achieved for example, by the installation of a second valve or a non-return valve. Suitable means shall be provided for preventing the build up of pressure of any trapped liquid. A7.6.13

Security fencing Fencing is required to prevent access of unauthorised persons, where other means are not provided. On controlled sites with sufficient supervision fencing is optional. Where fencing is provided and access around the tank is required for maintenance, the minimum clearance between the fence and the installation~ shall be 0.6 m to allow free access and escape from inside the enclosure. For ‘open’ fences, the safety distances given in Appendix 3 will apply regardless of the position of the fence. The height of the fence shall be approximately 1.8 m. Timber or other readily combustible materials shall not be used for fencing around oxygen tanks. Any gates should be outward opening and wide enough to provide for an easy access and exit of personnel. Gates shall be locked during normal operation. Consideration shall be given to the provision of an additional emergency exit where the size of fenced area or equipment location necessitates this. Any emergency exit gate should be, at least 0.8 m wide.

A7.6.14

Foundations The tank supplier will provide indicative foundation requirements but it is the responsibility of the user to ensure the tank foundation is designed to safely withstand the weight of the tank and its contents plus other possible loads resulting from wind, snow, earthquake etc.



A7.6.15

Bolting down Many factors determine whether a tank needs to be bolted down. The following are some of the main factors that should be considered:

• • • • • •

seismic activity wind speed topography (nature of surrounding terrain) ground roughness (open or protection provided) tank shape factor (L/D ratio, attachments to tank) the potential to tip the foundation.

The principles of BS 6399 shall be followed to determine bolting down requirements. A7.7

ACCESS TO THE INSTALLATION

A7.7.1

Means of Escape Consideration shall be given to the provision of an emergency exit where there is a risk of persons becoming trapped by a release of product.

A7.7.2

Personnel The installation shall be so designed that authorised persons shall have easy access to and exit from the operating area of the installation at all times. Access to the installation shall be forbidden to all unauthorised persons. Warning notices shall support this.

A7.7.3

Access to installation controls Filling connections and equipment controls shall be located in such a way that easy access to them is provided. Filling connections and equipment controls should be located in close proximity to each other and in such a way that tanker controls and indicators are visible and easily accessible from the tanker operator’s position.

A7.8

NOTICES AND INSTRUCTIONS

A7.8.1

General precautions Notices shall be clearly displayed, to be visible at all times, on or near the tank, particularly at access points, the following should be considered:

• • • • • • •

Liquid Natural Gas (LNG) no smoking no naked lights no mobile phones no storage of oil, grease or combustible materials authorised persons only extreme cold hazard.



These signs shall comply with the Health and Safety (Safety Signs and Signals) Regulations 1996 and with BS 5499 Pt 5 “Safety Signs and Colours”. A sign shall be displayed showing:

• •

Gas supplier’s name and local address Gas supplier’s emergency phone number.

This information should also be available at a control point. A7.8.2

Identification of contents The storage tank shall be clearly labelled "LIQUID NATURAL GAS"; The storage tank or compound should be clearly labelled with the appropriate UN product identification numbers.

A7.8.3

Legibility of notices All displayed notices shall be kept legible, visible and up-to-date at all times.



APPENDIX 8 : GUIDANCE FOR MINIMUM OPERATIONAL AND MAINTENANCE REQUIREMENTS This Appendix provides guidance to operators on the operation and maintenance of vehicle fuelling stations which dispense CNG as a motor vehicle fuel. A8.1

FILLING STATION OPERATION AND MAINTENANCE Adherence to good operating and maintenance practices and procedures minimizes the possibility of gas leakage and other incidents at a fuelling station.

A8.1.1

General

A8.1.1.1

All reasonable steps shall be taken to prevent gas leakage, fire and other incidents from occurring at a filling station. Note:

As vehicles having petrol and diesel fuel tanks may be using the fuelling station, consideration will have to be given to possible liquid fuel leakage (see Sub-Section 7.1.4).

A8.1.1.2

Any means of escape from areas of the fuelling station shall be free from obstruction at all times.

A8.1.1.3

All operational areas of the fuelling station shall be kept clear of combustible material and other material likely to cause a hazard.

A8.1.1.4

Adequate training of any person employed on the fuelling station shall be provided (see Sub-Section 7.5).

A8.1.1.5

Periodic examination, servicing and maintenance of plant in addition to the procedures in this Appendix should be undertaken, by a competent person, in accordance with the manufacturer's/supplier's/installer's instructions and/or the advice of the competent person who last carried out an examination.

A8.1.1.6

A

• • •

maintenance

scheme

shall

be

implemented

to

ensure:

the integrity of plant and equipment the presence and effectiveness of safety and emergency provisions the maintenance of the site in a condition free from hazards.

Maintenance shall be performed according to the manufacturer requirements. A8.1.1.7

Consideration shall be given to the minimisation of any gas leakage or venting from the installation, under both operational and maintenance conditions.

A8.1.1.8

Any modification to the equipment and/or layout of the fuelling station shall involve an appropriate risk assessment.

A8.1.2

Hazardous area zones

A8.1.2.1

Certain fuelling station equipment will be subject to hazardous area classification, which will restrict the type of electrical equipment and potential ignition sources, which can be placed in those zoned areas. Such restrictions shall be observed at all times.



A8.1.2.2

A copy of the drawing detailing the hazardous area zones. which would have been prepared when designing the station, should be kept at the fuelling station and updated as necessary.

A8.1.2.3

Where operations that may impinge on the zoned areas are planned, operating procedures (see Sub-Section 7.1.4) shall include suitable additional precautions.

A8.1.2.4

A periodic inspection and test program shall be carried out by a competent person to ensure that any electrical equipment in a hazardous zone is in a satisfactory condition and that the integrity of the hazardous zone is maintained.

A8.1.3

Precautions against leakage and incidents

A8.1.3.1

Gas carrying equipment shall be protected from mechanical damage by, for example, vehicles, vandalism, etc. at all times. Where gas carrying equipment has been subjected to mechanical damage, or has been found to be faulty, it shall be taken out of service until inspected by a competent person and any subsequent repair or replacement has been carried out.

A8.1.3.2

Gas carrying equipment shall be inspected at regular intervals, by a competent person, for leakage, damage or fault. See appendix J7.A and appendix 7.C

A8.1.3.3

Where a leakage of gas is identified, an appropriate emergency procedure (see Sub-Section 7.1.4) shall be implemented. The responsible person shall be notified.

A8.1.4

Operating and emergency procedures

A8.1.4.1

Comprehensive operating and emergency procedures shall be produced for all activities, for example inspection, testing, maintenance etc. and for all incidents having health and safety implications that could occur on the fuelling station. The precautions shall address risk and may require individual risk assessments to be undertaken for particular activities.

A8.1.4.2

Personnel shall be instructed in the implementation of any operating or emergency procedure that is appropriate to them.

A8.1.4.3

Copies of operating and emergency procedures shall be available for use and, where appropriate, be displayed in readily visible positions.

A8.1.4.4

All operational and emergency procedures should be reviewed on a regular basis.

A8.1.5

Notices and instructions The use of readily visible and understandable notices and instructions can assist in the safety of operations and the effectiveness of actions in the event of incidents.



A8.1.5.1

Suitable warning notices shall be erected in appropriate and readily visible positions around the fuelling station in order to:

• • • •

identify the location of emergency controls and equipment, for example gas isolation valves, isolation switches, fire extinguishers etc. identify potential hazards give notice of prohibitions, for example ‘No Smoking’ list operating/emergency procedures to be followed

A8.1.5.2

Notices and instructions shall be checked periodically for effectiveness.

A8.1.5.3

Safety notices should comply with SI 3864 Part 1 as appropriate.

A8.1.6

Emergency action and equipment

A8.1.6.1

Any applicable emergency procedure (see Sub-Section 7.1.4) shall be followed in the event of fire or emergency. Note:

A8.1.6.2

All appropriate isolation switches and valves will have been identified.

Adequate means for summoning the Emergency Services shall be available. Details of a point of contact in the event of an incident shall be displayed. Note:

A8.1.6.3

Guidance may be sought from the Emergency Services.

Suitable equipment, for example fire extinguishers etc., for controlling minor incidents and controlling the escalation of major incidents shall be installed and shall be in readily accessible positions. Guidance on the type, number and location of fire extinguishers and other equipment should be sought from the local Fire Authority.

A8.1.6.4

Consideration shall be given to the provision of a supply of dry sand or similar absorbent material, kept in a suitable container and placed in an accessible location, for use on small spills or leakage of liquid fuel.

A8.1.6.5

All emergency equipment shall be readily available and in a condition ready for immediate use. Equipment shall be checked regularly.

A8.2

GAS DISPENSING OPERATIONS A fuelling station may be either private or commercial having fast and/or slow-fill gas fuel dispensers. Fuelling Stations may not be permanently manned with an attendant/operator.

A8.2.1

Natural Gas shall be dispensed only into the fixed storage container(s) of a vehicle having a fuel system complying with the Ministry of Transportation requirements, except when a competent person is undertaking commissioning/testing/maintenance of equipment.

A8.2.2

The dispensing receptacle on the NGV shall be of a type which is directly compatible with the dispenser nozzle (see Sub-Section 7.4.2)

A8.2.3

Dispensers shall only be operated in accordance with the manufacturer's instructions. 63 ©IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk.


A8.2.4

Dispensing instructions and notices (see Sub-Section 7.1.5) shall be displayed clearly on or near the dispenser. Any notice of restriction shall be observed, for example ‘switch off ignition’, ‘no smoking’ etc.

A8.2.5

On private stations, fuelling shall be undertaken only by persons who have received suitable instruction. Unauthorized use of the equipment should be prevented.

A8.2.6

If a leakage of gas occurs during dispensing (other than a minor release of gas which can occur on disconnection), the emergency procedure shall be followed and the dispensing shall not recommence until a competent person has inspected the equipment and deemed it safe to continue.

A8.2.7

When a dispenser is taken out of service, it shall be labelled adequately to prevent inadvertent use and isolated from power.

A8.2.8

Any dispensing area of a fuelling station shall be adequately illuminated, at all times of use, in order to permit filling to be safely undertaken.

A8.2.9

On an unattended self service fuelling station, details of a point of contact shall be displayed in a suitable location for summoning assistance if difficulties arise with the fuelling operation.

A8.3

GAS STORAGE OPERATION

A8.3.1

Any individual gas container within the storage facility shall be examined and tested at regular intervals, as defined in EN 13445-1 and EN1964, or in the event of it being subjected to mechanical damage or significant corrosion.

A8.3.2

A container may need to be removed from the site for testing. Appropriate site procedures shall be applied to cover: • • • •

decommissioning removal replacement recommissioning.

Such procedures shall be carried out by competent persons only, paying due regard to the associated hazards. Note:

Arrangements for for a period of time.

testing

may

necessitate

closure

of

the

fuelling

station

A8.3.3

Testing shall be carried out only by competent person

A8.4

GAS COMPRESSOR OPERATIONS

A8.4.1

Suitable safe working systems, for example a ‘permit to work’ scheme on a larger installation, shall be employed for any work involving a compressor and its ancillaries.

A8.4.2

During periods of compressor maintenance, it may be possible to continue to supply gas from storage for dispensing. This shall be permitted only if a suitable means of isolation is in place to prevent automatic start up of the compressor.

A8.4.3

Work shall be carried out by competent persons only.



A8.5

TRAINING

A8.5.1

Any person working on a fuelling station shall be given adequate training and practical instruction to ensure that they fully understand and are aware of:

• • •

the hazards associated with Compressed Natural Gas the operating and emergency procedures the location and method of operation of any emergency equipment.

A8.5.2

Training records shall be kept and, periodically reviewed and any new or refresher training shall be provided as necessary.

A8.5.3

On private stations, persons who are to carry out fuelling of NGV at work shall receive training in the operation.

A8.6

RECORDS The management of safe operations at a fuelling station is aided by the maintenance of clear records of operational activities and any events that have a bearing on safety.

A8.6.1

Records shall be kept for activities covered by appropriate legislation.

A8.6.2

Additional records should be kept to cover other inspections, maintenance, modifications and repairs in order to allow, for example:

• • • •

safety and performance to be monitored and audited required modifications to be noted service and maintenance needs to be identified visiting contractors to review performance information.



APPENDIX 9 : INSPECTION OF GAS CARRYING EQUIPMENT, OPERATION AND EMERGENCY PROCEDURES AND MAINTENENCE SCHEDULES A9.1

INSPECTION OF GAS CARRYING EQUIPMENT The following gas carrying equipment needs to be inspected for evidence of gas leakage, damage or fault:

A9.1.1

Gas dispenser:

• • • A9.1.2

Gas pipework on the forecourt:

• • A9.1.3

containers vents associated pipework.

Gas meters:

• A9.2

gas compressor area surrounding the enclosure vents.

Gas storage area:

• • • A9.1.5

exposed pipework pipework in accessible ducts.

Emergency isolation valves:

• • • A9.1.4

hoses and nozzles operating valves dispenser body.

associated pipework.

OPERATION AND EMERGENCY PROCEDURES The following are examples of the type of situation/activity which may need to be covered by operating or emergency procedures. It is not intended to be an exhaustive list.

A9.2.1

Operating procedures

• • • • • • A9.2.2

start-up and shutdown of the fuelling station routine inspection and maintenance of station components major inspection and maintenance of station components work in hazardous area zones removal and replacement of storage containers operation of fuel dispensers.

Emergency procedures 66 ©IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk.


• • • • • • •

emergency shut-down of the station start-up following emergency shut-down emergency isolation of components action in the event of gas leakage during filling action in the event of gas leakage from components action in the event of fire/explosion action in the event of liquid fuel spillage.

A9.3

MAINTENENCE SCHEDULES

A9.3.1

The maintenance schedule provided is informative example only. Station operators must determine a maintenance schedule that considers the particular station design, environmental conditions, fuelling loads, operating hours, frequency of use and other factors impacting equipment use and wear.

A9.3.2

Not all maintenance items listed may be applicable to a particular installation and some items may be missing. The station owner should develop a customized maintenance schedule and develop safe maintenance intervals based on station experience and inspection requirements based on local regulating authorities.

A9.3.3

It is recommended that station maintenance intervals remain conservative (shorter) initially and then extended only if experience warrants it. Maintenance records should be prepared for each station, which can be dated and signed when undertaken and any issues identified and recorded.



APPENDIX 10 : CNG STORAGE IN BELOW GROUND PITS A10.1

Where above ground storage is not possible CNG storage may be located in suitably designed underground pits with the following requirements:

• • • • • • •

• Note:

a risk assessment shall support the below ground location The pit shall be designed and located to permit a means of regular inspection and to facilitate cylinder removal for revalidation tests Locations shall be chosen that are free of surface water or flooding. High water tables shall be avoided A suitably constructed concrete enclosure shall surround the pit forming a gas and water tight seal. The sides should extend slightly above ground level to prevent water ingress A sump shall be constructed in the base of the pit. It should be possible access the sump to facilitate the removal of collected water and debris The pit shall have an open top maximising ventilation of the pit The pit shall be protected by an open mesh metal cover designed to withstand foreseeable imposed loads. If the cover is not designed to withstand traffic the pit shall be protected from vehicles by suitable traffic barriers A safe means of access for inspection shall be provided. Access shall be controlled by confined space procedures

A10.1.1

Consideration shall be given to the application of additional corrosion protection to the storage cylinders and pipework.

A10.1.2

Any pressure reliefs devices located in the pit shall comply with Sub-Section 11.2.

A10.1.3

A gas detection system shall be located inside the pit.
