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CODE OF PRACTICE 41

THE DESIGN, CONSTRUCTION,

MAINTENANCE AND OPERATION OF

FILLING STATIONS DISPENSING

GASEOUS FUELS

REVISION 2: 2018

1 BCGA 41 – Revision 2

CODE OF PRACTICE 41

THE DESIGN, CONSTRUCTION, MAINTENANCE

AND OPERATION OF FILLING STATIONS

DISPENSING GASEOUS FUELS

REVISION 2: 2018

Copyright © 2018 by British Compressed Gases

Association. First printed 2014. All rights reserved. No

part of this publication may be reproduced or transmitted in

any form or by any means, electronic or mechanical,

including photocopy, without permission from the

publisher:

BRITISH COMPRESSED GASES ASSOCIATION Registered office: 4a Mallard Way, Pride Park, Derby, UK. DE24 8GX

Company Number: 71798, England

Website:

www.bcga.co.uk

ISSN 2398-9440

http://www.bcga.co.uk/


PREFACE

The British Compressed Gases Association (BCGA) was established in

l971, formed out of the British Acetylene Association, which existed

since l901. BCGA members include gas producers, suppliers of gas

handling equipment and users operating in the compressed gas field.

The main objectives of the Association are to further technology, to

enhance safe practice, and to prioritise environmental protection in the

supply and use of industrial, food and medical gases, and we produce a

host of publications to this end. BCGA also provides advice and makes

representations on behalf of its Members to regulatory bodies, including

the UK Government.

Policy is determined by a Council elected from Member Companies,

with detailed technical studies being undertaken by a Technical

Committee and its specialist Sub-Committees appointed for this

purpose.

BCGA makes strenuous efforts to ensure the accuracy and current

relevance of its publications, which are intended for use by technically

competent persons. However this does not remove the need for

technical and managerial judgement in practical situations. Nor do they

confer any immunity or exemption from relevant legal requirements,

including by-laws.

For the assistance of users, references are given, either in the text or

Appendices, to publications such as British, European and International

Standards and Codes of Practice, and current legislation that may be

applicable but no representation or warranty can be given that these

references are complete or current.

BCGA publications are reviewed, and revised if necessary, at five-

yearly intervals, or sooner where the need is recognised. Readers are

advised to check the Association’s website to ensure that the copy in

their possession is the current version.

This document has been prepared by BCGA Technical Sub-

Committee 9. This document replaces BCGA Code of Practice 41,

Revision 1: 2016. It was approved for publication at BCGA Technical

Committee 159. This document was first published on 23/10/2018.

For comments on this document contact the Association via the

website www.bcga.co.uk.



CONTENTS

Section Page

TERMINOLOGY AND DEFINITIONS 6

1. INTRODUCTION 12

2. SCOPE 16

3. RISK MANAGEMENT 19

3.1 General 19

3.2 Principle legal requirements 19

3.3 Environmental risk assessments 20

4. PRE-DESIGN 21

5. PLANNING PERMISSION AND PERMITS 22

5.1 General 22

5.2 Storage 22

5.3 Multi-fuel stations 23

6. LAYOUT AND SITE SELECTION CRITERIA 23

6.1 General 23

6.2 Location of storage installation 24

6.3 Access and egress for fuel delivery vehicles 28

6.4 Location and installation of dispensing points 30

6.5 Connecting pipework 31

6.6 On-site fuel generation equipment and related process

equipment.

32

6.7 Vent systems 32

6.8 Vent recovery 32

6.9 Other filling station activities 33

7. DESIGN OF FILLING STATION 33

7.1 General 33


7.2 Fuel gas storage and process equipment 40

7.3 LNG vaporiser 43

7.4 Fuel delivery 44

7.5 Connecting pipework and valves 44

7.6 Dispensing equipment 45

7.7 Venting and vent stacks 49

7.8 Dispenser plinth earthing and grounding 50

7.9 Canopy 50

7.10 Gas fuels on multi-fuel stations 50

8. INSTALLATION AND COMMISIONING 50

8.1 Installation 50

8.2 Pre-commissioning 50

8.3 Commissioning 53

8.4 Handover for operation 54

8.5 End of life 56

9. OPERATION 56

9.1 Delivery 56

9.2 Vehicle filling – Fuel dispense 57

10. PERIODIC EXAMINATION & MAINTENANCE 59

11. FUEL QUALITY 61

11.1 Proton Exchange Membrane hydrogen 62

11.2 Non-Proton Exchange Membrane hydrogen 63

11.3 CNG and LNG 63

12. COMPETENCE OF PERSONNEL INCLUDING TRAINING 64

13. PERSONNAL PROTECTIVE EQUIPMENT 68

13.1 Public access filling 68

13.2 Non-public access filling 68


13.3 Maintenance and fuel delivery 68

14. EMERGENCY SITUATIONS AND PROCEDURES 68

15. SECURITY 70

16. REFERENCES * 71

APPENDICES:

APPENDIX 1 Minimum recommended separation distances for hydrogen

storage installations

81

APPENDIX 2 Minimum recommended separation distances for natural

gas storage installations

82

APPENDIX 3 Hydrogen - General data and safety considerations 83

APPENDIX 4 Natural gas - General data and safety considerations 85

APPENDIX 5 Checklist for approval to install and operate filling stations 87

APPENDIX 6 Checklist for emergency services 88

* Throughout this document numbers in brackets refer to references in Section 16. Documents

referenced are the edition current at the time of publication of this Code of Practice, unless

otherwise stated.


TERMINOLOGY AND DEFINITIONS

Assembly A number of parts or combination thereof that are joined together to

perform a specific function and subject to disassembly without

degradation of any of the parts, e.g. a hose assembly combining a

nozzle, hose set and breakaway coupling.

Biomethane Biomethane is upgraded Biogas, a natural occurring gas with similar

properties to natural gas, produced by the anaerobic digestion of

waste such as organic matter, food waste, sewage, landfill etc. It

can be stored in two forms, compressed (CBG) or liquefied (LBG).

Boil-off gas Gas emissions caused by the evaporation of a liquefied gas in

storage tanks and other parts of the station.

Break-away device A device that stops the flow of gas allowing safe disconnection from

the fuelling system in the event of accidental disconnection, i.e. a

vehicle drive-away when the hose is still connected.

Bulk storage For the purposes of this document bulk storage is defined as fuel gas

storage which consists of either:

fixed gas cylinders manifolded together; or

tubes which may be either fixed in place or mounted on a transportable trailer; or

one or more liquefied gas vessels.

Bundle Assembly of cylinders that are fastened together and which are

interconnected by a manifold and transported as a unit, having a total

water capacity not exceeding 3000 litres.

Bund A containment structure typically made of concrete that diverts a

liquefied gas to a safe area for dissipation into the atmosphere.

Canopy A roof, overhead shelter, or hood providing the station or fuel

dispenser with a degree of weather protection.

Competence The employer is responsible for ensuring that employees are

competent to carry out each task safely and correctly. For

additional information on competence refer to BCGA GN 23 (97),

Gas safety. Information, instruction and training.

There are specific roles, such as a ‘Competent Person’, which are

defined in legislation, for example, the Pressure System Safety

Regulations (11).

Compressed

natural gas

Compressed natural gas (CNG), including methane and biomethane.


Control point A position in a kiosk or other building at an attended self-service

filling station from which an attendant can view and supervise

activities at the dispenser, activate the equipment, and shut-off the

dispenser, in the case of emergency.

Cryogenic Cryogenic liquids are liquefied gases that are kept in their liquid

state at very low temperatures, typically lower than -150 °C.

Cylinder Transportable pressure receptacle of a water capacity not exceeding

150 litres.

Dead man’s button

/ switch

A device that automatically shuts down an operation in a safe

manner, i.e. when refuelling a vehicle or during a fuel transfer.

Automatically operated if the operator releases pressure on the

button/switch.

Deflagration A rapid chemical reaction in which the output of heat is sufficient to

enable the reaction to proceed and be accelerated without input of

heat from another source. Deflagration is a surface phenomenon

with the reaction products flowing away from the unreacted material

normal to the surface at subsonic velocity. The effect of a

deflagration under confinement is an explosion. Confinement of the

reaction increases pressure rate of reaction and temperature and may

cause transition into a detonation.

Detonation An exothermic reaction wave which follows, and also maintains, a

supersonic shock front from an explosion. Such transitions are

promoted by the increased turbulence arising from a deflagration

flame front interacting with strong structures.

Dispenser Pump or equipment used to dispense fuel at a filling station.

Docking station A docking station is a housing, pad or post where the dispenser

nozzle is stored to prevent damage, ingress of dirt, or moisture. A

docking station for an LNG nozzle may be heated to prevent the

build up of ice and condensation.

Dry air Air with a maximum dew point of -40 ºC.

Embrittlement Embrittlement is a loss of ductility of a material making it brittle.

Embrittlement of some carbon steels may be caused as a result of

exposure to low temperature gases, for example, from a liquefied

gas. Hydrogen embrittlement is the effect of hydrogen absorption

on some metals and alloys. The degradation of a structural material

may result in failure or a leak.

Explosion A nuclear, chemical or physical process leading to the sudden

release of energy (and usually gases and heat) giving rise to external

pressure waves.


Equipment supplier

/ installer

The company or companies, as contracted by the Owner / User, to

provide and install the equipment used to store, distribute and

dispense a specific fuel gas.

Fast-fill For natural gas, a filling operation that takes a similar amount of

time as current liquid fuels to fill.

Filling station A facility for the storage and dispensing, normally to the general

public, of products used as fuels for motor vehicles. These can

include petrol, diesel, autogas (LPG), hydrogen, CNG, LNG and

LCNG.

NOTE: Hydrogen filling stations may typically be referred to as

Hydrogen Refuelling Stations (HRS), however the term filling

station is used for consistency with other UK documents concerning

petrol, diesel and LPG filling stations.

Flammable gas Gases which at 20 °C and at standard atmospheric pressure:

(i) are ignitable when in a mixture of 13 % or less by volume with air; or

(ii) have a flammable range with air of at least 12 percentage points regardless of the lower flammability limit.

Forecourt attendant Responsible to the Site Operator. Directly operates and controls

the dispenser and the discharge nozzle on behalf of the customer.

Gas supplier The company contracted by the Owner / User to provide a specific

fuel gas product for dispense at the filling station.

Gaseous storage A system which includes containers, pressure regulators,

instruments, safety-relief devices, manifolds, inter-connecting

piping and controls. The storage system terminates at the point

where the gas enters the distribution piping.

Hazardous area Any place in which an explosive atmosphere may occur in quantities

such as to require special precautions to prevent ignition during

construction, installation or use, as applicable.

Heavy goods

vehicle

Heavy Goods Vehicle (HGV) (also known as LGV, Large Goods

Vehicle). Commercial truck with a gross combination mass of more

than 3500 kg.

Installation Equipment (vessels, pumps, compressors, electrolysers, reformers

etc.), pipework, hoses, valves, instruments etc. that have been

assembled into one or more systems that enable the generation,

storage or dispensing of gaseous fuels.


Invacuation A variant of the commonly understood concept of evacuation (for

example, in the event of a fire). Invacuation involves the removal

of people to an alternative area within the site.

Leakage See Methane Leakage

Liquefied

Compressed

Natural Gas

(LCNG)

LNG warmed and vaporised to product CNG for dispensing

Liquefied natural

gas

Liquefied natural gas (LNG), including methane and biomethane

(LBG).

LNG Vaporiser A heat exchanger used for regasifying liquefied gases.

LPG Liquefied petroleum gas

Maintenance staff Typically employed by the equipment supplier / installer, or the

gas supplier. Has significant understanding of the design and

operational elements of both the gas dispensing and storage /

generation equipment, as appropriate.

May An option available to the user of this Code of Practice.

Methane leakage The loss, emission of methane due to leakage, venting, coupling

losses, for example, of the storage system. This concept is distinct

from that of ‘methane slip’, which concerns poor combustion

(combustion efficiency) i.e. in a vehicle using an internal

combustion engine. Methane leakage has an undesirable

environmental and safety impact.

Mobile station A fueling station that can be transported with product onboard.

Mobile workers Persons who work in more than one place or travel as part of their

job, i.e. HGV and public service vehicle drivers.

Multi-fuel

dispenser

Dispenser delivering multiple fuels, liquid or gaseous.

Non-hazardous area Any place in which an explosive atmosphere is not expected to

occur in quantities such as to require special precautions to prevent

ignition during construction, installation and use.

Odorization The process of adding an odorant to gas in order that it can be

detected by smell.

Owner / user The owner of a filling station. Within this Code of Practice the

owner has the same responsibilities as the user, as defined in the

Pressure Systems Safety Regulations (11).


Public service

vehicle

Public service vehicle. A vehicle such as a bus used by members

of the public to travel to and from places on particular routes.

Self-service

attendant

Responsible to the site operator. Supervises customers operating

dispensers, with the responsibility to activate or, in the case of

emergency, shut-off the dispenser from a defined control point.

Separation

distances

Horizontal and vertical distances between the nearest part of the

gas storage and distribution system and any specified feature (for

example, occupied buildings, facilities, process areas, site

boundary). The purpose of a separation distance is to protect the

gas storage and distribution system from heat radiation should

there be a fire in the local area, also to protect the local area from

the effects of a fuel gas release. The intention is to provide

sufficient time for emergency evacuation as appropriate and the

mobilisation of additional fire-fighting equipment.

NOTE: The term separation distance should not be confused with

the distances involved with hazardous area classification.

Shall Indicates a mandatory requirement for compliance with this Code

of Practice and may also indicate a mandatory requirement within

UK law.

Should Identifies a preferred, but not mandatory requirement for

compliance with this Code of Practice.

Site operator Responsible to the owner / user. Person (or company) in charge of

(with day to day control) a filling station i.e. the petroleum spirit

licence holder. In some cases this will be the owner.

Slow-fill For natural gas, a slow (or timed) filling operation that takes a

longer amount of time than current liquid fuels to fill, and can take

several hours.

Tanker stand The position on a filling station where a fuel delivery tanker is

located during the fuel delivery process.

Tube A transportable pressure receptacle of seamless or composite

construction having a water capacity exceeding 150 litres and of not

more than 3000 litres.

NOTE: Tube design is evolving and it is possible to obtain tubes

with a water capacity greater than 3000 litres, but these do not

comply with the current transport Regulations which define a tube.

Unattended self-

service

A filling station where the dispenser is activated and operated by a

customer without supervision by an attendant.

Venting Controlled and uncontrolled release of gas into the atmosphere.


Vapour recovery

equipment

Recovers boil-off gas to prevent it from escaping into the

atmosphere. Equipment may include a receiver, ambient vaporiser,

compressor and buffer storage, enabling recovered gas to be

dispensed as CNG. It may also consist of an assembly for re-

liquefying boil-off gas from the vehicle fuel tank or road tanker,

which is returned as LNG to the station storage vessel.

Vulnerable

populations

Vulnerable populations include those who may not be easy to

evacuate from premises because of, for example, age or infirmity,

including schools, hospitals, old people’s homes and other

residential accommodation.


CODE OF PRACTICE 41

THE DESIGN, CONSTRUCTION, MAINTENANCE AND OPERATION

OF FILLING STATIONS DISPENSING GASEOUS FUELS

1. INTRODUCTION

Globally there is a growing awareness of the environmental concerns around the use of

traditional fuels. Low, or zero emissions from exhausts and a reduced carbon footprint are

part of the future. The use of alternative fuels for vehicles is becoming more widespread in

the UK. The use of liquefied petroleum gas (LPG) is well established and the technical and

safety requirements for other gaseous fuels are being developed. All fuels are subject to UK

legislation or guidance.

Alternative gaseous fuels have a part to play in reducing UK carbon emissions, as recognised

in the European Commission Clean Power for Transport package of measures, which aims to

ensure the build-up of alternative fuel stations across Europe together with common standards

for their design and use. This package includes a European alternative fuels strategy,

European Communication 2013/17/EC (31), and a Directive on the deployment of a

European alternative fuels infrastructure, European Directive 2014/94/EU (35). To

implement this Directive the UK has enacted the Alternative Fuels Infrastructure Regulations

(23).

A number of international standards, national standards and industry documents from other

countries relating to the design and operation of alternative fuel vehicle filling stations have

been published, or are currently in the process of being developed.

The British Compressed Gases Association (BCGA) recognises that the alternative gaseous

fuels industry is still developing and this document signposts the important points of multiple

guidance documents.

The BCGA acknowledges that there are discrepancies between several of these documents

and that there will inevitably be revisions required in future. However, given the legally-

binding UK national requirement to reduce carbon emissions, the BCGA has taken the

decision to publish this signpost document to facilitate the timely development of alternative

gaseous filling station infrastructure.

The BCGA seeks to provide with this Code of Practice a minimum industry standard to

ensure a consistent high level of safety and to provide a reference document for those

involved in the design, planning, operation and regulatory approval of alternative gaseous

fuel stations.

The BCGA will review this document at intervals to continually reflect the experience of this

growing industry and welcomes suggestions from interested parties.

This code of practice is intended to outline the major technical and safety considerations

required in the UK during the design, construction, maintenance and operation of vehicle

filling stations which incorporate filling facilities for liquefied natural gas (LNG),


compressed natural gas (CNG) and hydrogen (H2), drawn from existing BCGA publications

and other major documents in order to comply with more general safety regulations and to

ensure safe operation.

For more traditional vehicle fuels such as petrol, diesel and LPG , the primary publication for

the requirements of the design, construction, modification, maintenance and

decommissioning of filling stations, published by the Association for Petroleum and

Explosives Administration (APEA) and Energy Institute (EI), is the Design, construction,

modification, maintenance and decommissioning of filling stations (the Blue Book) (103). It

has been produced jointly by the APEA and the EI with input from the Health and Safety

Executive (HSE) and other industry stakeholders.

This code of practice is designed to be complementary to the Blue Book (103). Where

gaseous fuels and traditional fuels are dispensed at the same filling station, due regard should

be taken of both this code of practice and the Blue Book (103). Specific guidance for

dispensing hydrogen alongside traditional vehicle fuels is available in a supplement to the

Blue Book (103), Guidance on hydrogen delivery systems for refuelling of motor vehicles co-

located with petrol fuelling stations (104), which has been jointly developed by the EI, APEA

and BCGA.

There are differences between the various gaseous fuels covered by this code of practice and

these should be taken into account.

Whilst both CNG and gaseous hydrogen are typically stored at high pressure, the pressures

involved in hydrogen vehicle filling are likely to be considerably higher than those involved

with CNG vehicle filling. The risk of harm / damage to the surroundings due to leakage from

the installation should therefore take into consideration the storage and operational pressures

of the gas, and may require more extensive safeguards for high pressure hydrogen systems.

In addition, the security of the storage and delivery areas shall be assessed. It is likely

however that both CNG and hydrogen fuel installations will have the same risk of damage by

3rd parties etc. Thus civil engineering protection of both types of filling stations is similar.

The principle hazards associated with hydrogen are:

Flammability;

Asphyxiation;

Material embrittlement and subsequent mechanical failure;

Increased likelihood of leakage from joints, due to smaller molecular size and where applicable, higher pressures;

Undetected leaks due to lack of odour;

Undetected fire due to invisible flame;

Increased likelihood of ignition of a leak;

For liquid hydrogen, cold burns when exposed to the skin;


Increased risk of injury as a result of uncontrolled release of high pressure gas;

Potential transition of an explosion from deflagration to detonation.

CNG and LNG are relatively new road fuels in the UK. Although natural gas as an energy

source for domestic households, commercial property and industry is well accepted, there are

major differences that have to be observed when using natural gas as a road fuel.

CNG is natural gas that has been compressed to a high pressure, typically 200 to 300 bar (20

to 30 MPa) in order that large volumes of energy can be stored, enabling it to be used in

vehicles as a replacement or substitute to current liquid fuels. The high-pressure gas can be

stored in steel or composite cylinders of various diameters and lengths.

The principle hazards associated with CNG are as follows:

Flammability;

Asphyxiation;

Undetected leaks due to lack of odour, where applicable;

Undetected fire due to difficult to see flame. CNG has a blue flame, which under certain light conditions may be hard to see.

Increased risk of injury as a result of uncontrolled release of high-pressure gas.

LNG is natural gas in a liquid form, as a cryogenic it is cooled to approximately -162 ºC. It is

mainly used as an energy source for heavy-duty road transport and can be converted back

into a gaseous state when delivered to a cryogenic storage vessel and warmed to ambient

temperature.

The principle hazards associated with LNG are as follows:

Flammability;

Asphyxiation;

Cold burns when exposed to the skin;

Undetected leaks due to lack of odour;

Undetected fire due to difficult to see flame;

Material low-temperature embrittlement and subsequent mechanical failure (to mild and carbon steels);


If LNG is released it flashes. The vapours are initially heavier than air and will form a gas cloud close to the ground, which will eventually dissipate. However, under

specific conditions, where a vapour cloud exists with LNG between its lower and

higher flammability limits in air (5 % to 15 %), if a source of ignition is present the

vapour cloud could ignite, and this may be some distance from the actual release

source. Vapour clouds also introduce hazards from the visual impairment they create.

Other specific considerations are outlined in Appendix 4.

Some of the important international reference documents addressing the design and operation

of hydrogen vehicle filling stations include:

ISO/TS 20100 (64), Gaseous hydrogen. Fuelling stations. (Document withdrawn, reference only).

ISO/TS 19880 (63), Gaseous hydrogen. Fuelling stations. Part 1. General requirements.

USA - NFPA 2 (109), Hydrogen technologies code.

Germany - VdTÜV MB DRGA 514 (113), Requirements for hydrogen fuelling stations, Compressed gases 514.


of CNG vehicle filling stations include:

ISO 16923 (56), Natural gas fuelling stations. CNG stations for fuelling vehicles.

The Institute of Gas Engineers and Managers (IGEM) UP/20 (99), Natural gas fuelling stations.

USA - NFPA 52 (110), Vehicular natural gas fuel systems code.

Germany - G651/vdTUV M510 (112), Natural gas stations.

Netherlands – PGS 25 (114), Natural gas delivery systems for vehicles.

Israel - SI 6236 (116), Compressed natural gas (CNG) fuelling stations for vehicles.


of LNG vehicle filling stations include:

ISO 16924 (57), Natural gas fuelling stations. LNG stations for fuelling vehicles.

IGEM/UP/21 (100), Liquefied natural gas fuelling stations. (Draft under development).

NFPA 52 (110).


Netherlands – PGS 33 (115), Natural Gas. Liquefied natural gas (LNG) delivery installations for vehicles.

Other relevant documents that may be of interest to the reader are listed in Section 16.

This document is not a Design Code. The user of this Code of Practice shall make reference

where applicable to UK legislation and internationally recognised Standards where these

apply and should also take into account the specific practices of the UK industrial gases

companies.

All new installations or modifications to existing installations shall, as far as is reasonably

practicable, comply with this Code of Practice for the products or services involved.

This Code of Practice, along with the range of other BCGA publications, represents the

BCGA’s view of minimum requirements for safe practice.

2. SCOPE

This Code of Practice covers the location, design, installation, commissioning, operation,

maintenance and inspection of equipment used in a filling station for vehicle filling with

gaseous hydrogen, CNG, or LNG, with or without the dispensing of other vehicle fuels such

as petrol, diesel, liquefied petroleum gas (LPG) etc.

This document covers the delivery or on-site generation of the fuel (including compression as

appropriate), and equipment associated with storage and dispensing of the fuels included in

the scope. It includes guidance on emergency procedures, appropriate signage, and the

requirement for competent operating staff for the site, it also covers those carrying out filling

activities, which may include members of the public.

Storage of the fuel may be as a compressed or liquefied gas.

Recommendations of best practice are outlined to assist in compliance with UK regulations to

ensure the safety of the general public, and employees at a vehicle filling station:

BCGA Code of Practice (CP) 4 (91), Industrial gas cylinder manifolds and gas distribution pipework (excluding acetylene), covers the distribution of gases.

BCGA CP 33 (92), The bulk storage of gaseous hydrogen at users’ premises, covers storage and distribution of gaseous hydrogen in the UK.

BCGA CP 39 (93), In-service requirements of pressure equipment (gas storage and distribution systems).

BCGA CP 44 (94), The storage of gas cylinders, where gas cylinders are not connected.

BCGA CP 46 (95), The storage of cryogenic flammable fluids, covers the storage of liquid hydrogen and LNG in the UK.


IGEM UP/20 (99) covers the supply of natural gas from the grid or mobile CNG storage, compression and dispensing of CNG to vehicles in the UK.

IGEM UP/21 (100) covers the supply of LNG from road tanker to storage and dispensing of LNG to vehicles and mobile stations in the UK.

NOTE: IGEM UP/21 (100) is still under development.

The relationship and interactions between these primary documents prepared to cover LNG,

CNG and hydrogen vehicle filling is shown in Figures 1 & 2. Where petrol is also dispensed

at the filling station, the requirements of the Blue Book (103 & 104) should be addressed.

Further reference appropriate to the use of flammable gases in the UK is made to:

European Industrial Gases Association (EIGA) Document 6 (82), Safety in storage, handling and distribution of liquid hydrogen.

EIGA Document 15 (83), Gaseous hydrogen stations, covers gaseous hydrogen, compression, purification, filling into containers and storage installations at consumer

sites.

BS EN 13645 (47), Installation and equipment for liquefied natural gas. Design of onshore installations with a storage capacity between 5t and 200t, in the primary

case.

In the absence of any other appropriate UK guidance for gaseous fuelled vehicle filling,

separation distances have been incorporated based on existing published guidance. It should

however be recognised that those currently included for compressed hydrogen, taken from

BCGA CP 4 (91) and BCGA CP 33 (92), are not necessarily intended for the pressures

encountered in a hydrogen vehicle filling station, which can be as high as 1000 bar. To allow

for this, where these distances are used, a reduced maximum internal pipe diameter of 8 mm

is recommended for hydrogen systems above 200 bar. For greater pipe diameters, it may be

appropriate to extend these distances. For systems operating at lower pressures, e.g.

production equipment, these separation distances may be conservative, and other methods of

determining the appropriate separation distances may be justifiable.

For potential leak points in the pipework and equipment involved in the dispensing of

gaseous hydrogen, isolated from the storage vessels outside of a filling activity, separation

distances taken from BCGA CP 4 (91) are recommended, again assuming a maximum

internal pipe diameter of 8 mm.

This Code of Practice does not include the requirements for a gaseous-fuelled vehicle, for

which up-to-date information should be sought from the Department for Transport (DfT). It

does not cover the general requirements of petroleum, diesel or liquid petroleum gas (LPG)

vehicle filling station, which are all adequately covered in other industry standard

publications. For information on LPG refer to the UKLPG Trade Association and their

document UKLPG CP 20 (117), Automotive LPG refuelling facilities.


Figure 1. LNG and CNG

Figure 2: Hydrogen


3. RISK MANAGEMENT

3.1 General The control of risks shall be managed throughout the lifetime of the filling station.

Suitable and sufficient risk assessments shall be conducted. Advice on carrying out

risk assessments is available on the BCGA website (www.bcga.co.uk – Gas Topics –

Risk Assessments).

3.2 Principle legal requirements

Health and Safety at Work etc. Act

Compliance with Health and Safety at Work etc. Act (1) and its subsidiary health and

safety legislation shall be maintained and should be demonstrable.

Management of Health and Safety at Work Regulations

The Management of Health and Safety at Work Regulations (10) contain general

requirements for employers and the self-employed to assess the risks to workers and

others (including the general public) who may be affected by their undertaking, so that

they can decide on what measures should be taken to comply with health and safety

law.

ATEX Directives / Dangerous Substances and Explosive Atmospheres Regulations

Areas in filling stations used for the production, storage and dispensing of flammable

gases are within the scope of the Dangerous Substances and Explosive Atmospheres

Regulations (DSEAR) (14) and will require a risk assessment, with classification into

appropriate hazardous areas, based on the anticipated size of a release of flammable

material and the degree of ventilation in each area.

Further guidance is available in HSE L138 (79), DSEAR. Approved code of practice

and guidance. Guidance on DSEAR (14) risk assessments is available in BCGA

Guidance Note (GN) 13 (96), DSEAR Risk Assessment.

In the UK the requirements of the ATEX Workplace Directive (25) were put into effect

through DSEAR (14). The requirements of the ATEX Equipment Directive (24) were

implemented by the Equipment and Protective Systems Intended for Use in Potentially

Explosive Atmospheres (EPS) Regulations (6). Compliance with DSEAR (14) and the

EPS Regulations (6) is sufficient to confirm compliance with these Directives.

NOTE: ATEX is the name commonly given to the two European Directives for

controlling explosive atmospheres. These are:

European Directive 99/92/EC (25) (also known as 'ATEX 137' or the 'ATEX Workplace Directive') on minimum requirements for improving the health

and safety protection of workers potentially at risk from explosive atmospheres.

European Directive 94/9/EC (24) (also known as 'ATEX 95' or 'the ATEX Equipment Directive') on the approximation of the laws of Members States

concerning equipment and protective systems intended for use in potentially

explosive atmospheres.



All equipment installed in hazardous areas shall be appropriately certified according to

the ATEX Equipment Directive (24) for the type of hazardous area in which the

equipment is installed. On sites where multiple fuels are dispensed, consideration shall

be given to the properties and hazards of each fuel. This may require different ATEX

gas group classifications, for instance for hydrogen installations which due to the low

ignition energy of hydrogen, require equipment rated for gas group IIC hazardous

areas.

A document defining the hazardous areas associated with the plant and equipment

throughout the life cycle of the plant and the safety precautions that need to be taken

shall be created and kept up to date. This could take the form of a DSEAR (14) risk

assessment or an Explosion Protection Document, refer to the ATEX Workplace

Directive (25). Notably DSEAR (14) makes no mention an Explosion Protection

Document but the requirement for up to date information is very much a part of the UK

regulation and an Explosion Protection Document fits the need.

Where gaseous fuels and traditional fuels are dispensed at the same filling station,

specific guidance for the hazardous areas associated with petrol and diesel delivery,

storage, dispensing and service ducts and chambers etc. is available in the Blue Book

(103 & 104).

For specific information for natural gas installations refer to IGEM SR/25 (101),

Hazardous area classification of natural gas installations.

Provision and Use of Work Equipment Regulations

The Provision and Use of Work Equipment Regulations (PUWER) (9) requires that an

inspection and maintenance regime shall be in place to ensure the safety and suitability

of equipment on site. Refer to BCGA CP 39 (93).

Pressure Systems Safety Regulations

The Pressure Systems Safety Regulations (PSSR) (11) require a Written Scheme of

Examination to be drawn up or certified by a competent person. Examinations shall be

undertaken prior to use and thereafter in accordance to the Written Scheme of

Examination. For further information refer to HSE L122 (77), Safety of pressure

systems. PSSR 2000. Approved Code of Practice, and BCGA CP 39 (93).

Refer to Section 7, Design of filling station, for all other relevant legislation.

3.3 Environmental risk assessments

Risk assessments shall take into consideration the potential effect of gaseous fuels on

the environment.

Specific legislation requires environmental risks from dangerous, hazardous or

polluting substances to be assessed and controlled and it is therefore important that any

risk assessment is carried out not in isolation but as part of an overall assessment for a

site. Consideration may be required for potential cross-contamination of and

interaction between different products.

Where environmental risks dictate, for example, where fuel spillages may have an

impact, an effective incident response plan should be implemented.


European Directive 2010/75/EU (28) on industrial emissions (integrated pollution

prevention and control) (IED), requires permits where a site is manufacturing

hydrogen. This is implemented in the UK through legislation such as the

Environmental Permitting (England and Wales) Regulations (22) and the Pollution

Prevention and Control (Scotland) Regulations (16).

4. PRE-DESIGN

The pre-design phase is a recommended important step in the station design and installation

process. The level of detail should be suitable to determine all relevant factors including

existing site conditions and refuelling requirements.

The pre-design assessment should consider:

Location - new or integration into existing;

Size and types of vehicles to be refuelled;

Retail or non-retail; public or private access;

Permanent or mobile facility;

Projected growth;

Fuelling behaviour and ergonomics (personnel and vehicles), access and egress, and vehicle traffic flow on site;

Fuel type(s);

Fuel quality;

Integration with existing fuels on site (e.g. in compliance with the Blue Book (103 & 104), etc.);

Number and type of dispensers to meet refuelling requirements, including any interoperability requirements, refer to the Alternative Fuels Infrastructure Regulations

(23);

Planning permission and permit control;

Quantity of fuel to be stored (consents and permitting), including compliance, as appropriate, with the Control of Major Accident Hazards Regulations (COMAH) (19);

Available space, boundary and separation distances;


Available utilities (water, access to grid, electrical power);

Site conditions in relation to construction (wind loading, stability for vertical vessels or other equipment, seismic activity if applicable, flood risks, etc.);

Location of drains, manholes and culverts and other services including overhead and underground power lines;

Civil engineering;

Dedicated off-loading areas for incoming fuel deliveries, refer to BCGA CP 46 (95);

Tanker movements on site;

Site management, supervision and security.

5.0 PLANNING PERMISSION AND PERMITS

5.1 General

Responsibility for planning rests with the local planning authorities (in accordance with

the Town and Country Planning Act (2)). If planning permission is required, it should

be obtained before any work begins. The local fire authority should be involved at

planning stage.

Stability and ground evaluation, landscaping, height restrictions and grid connection

should all, where relevant, be taken into consideration.

Generation of hydrogen on site, (whether from steam methane reforming (SMR),

electrolysis or other sources), for commercial activities currently requires a permit

under the IED (28), refer to Section 3.3.

5.2 Storage

Depending on the quantity of stored fuel gas, refer to Table 1, consent may be required

from the Hazardous Substances Authority (HSA) in accordance with the Planning

(Hazardous Substances) Regulations (20) or the COMAH (19) Regulations. Under

COMAH (19), where sub-threshold quantities of dangerous substances are stored,

consideration should be given to the total quantity of products stored on a site

according to the aggregation rule, this will include petroleum, diesel, LPG and other

listed substances, in addition to any alternative vehicle fuels.

NOTE: The requirements of the EU Seveso III Directive 2012/18/EU (30) are

implemented by COMAH (19) in the UK.

In addition, the Dangerous Substances (Notification and Marking of Sites) Regulations

(NAMOS) (5) require notification to the authorities where a total quantity of hazardous

products of 25 tonnes or more are stored. Specific exemptions apply.


Planning (Hazardous

Substances) Regulations

COMAH Regulations

Lower tier Upper tier

Hydrogen 2 tonnes 5 tonnes 50 tonnes

CNG 15 tonnes 50 tonnes 200 tonnes

LNG 15 tonnes 50 tonnes 200 tonnes

Table 1: Thresholds for the different fuel gases

5.3 Multi-fuel stations

The Petroleum (Consolidation) Regulations (17) require that anyone operating a petrol

filling and/or storage station shall have a storage certificate issued by their local

Petroleum Enforcement Authority (PEA). The PEA will usually require the installation

to meet the requirements of the Blue Book (103 & 104).

The requirement applies both to retail and non-retail filling stations i.e. those that

dispense petrol to the general public and those, which only dispense petrol into their

own vehicles. As part of the PEA assessment of a petrol filling station, prior to issuing

a storage certificate, the PEA will ensure that the arrangements for any other fuels

stored and dispensed on the site are also appropriate, and that the risks associated with

the fuels are controlled so as not to impact upon each other.

6. LAYOUT AND SITE SELECTION CRITERIA

6.1 General

Storage installations and production equipment shall be contained within secured areas.

Table 2 displays the typical components of an installation for various fuels.

The principle hazard from gaseous fuels is fire, but there may also be an environmental

hazard. Certain gases, such as methane or refrigerant gases, if released, are greenhouse

gases. Hydrogen does not generally have an environmental impact. Where there is an

impact on traditional fuels (petrol, diesel) these can contaminate the local land (and

therefore water courses). Where assessments for different hazards (i.e. fire and

environmental) indicate different standards are required then the most stringent control

measures should be applied.

Where multiple fuel types are installed on a site, it may be useful to consider the detailed

design of these areas separately, although the influence of each area on other aspects of

the filling station shall also be reviewed holistically within the risk assessment. This is

particularly important where there are a large number of variables and there are gaps or

inconsistencies in standards and guidance, as may be the case with these emerging

technologies. Risk assessments shall take into account the anticipated effects and

consequences, including those offsite, of potential fire and explosion hazards.

Recommended minimum separation distances to non-classified electrics on installations

are listed in Appendix 1 and Appendix 2.


Fuel as

stored

Fuel

deliveries

Fuel as

dispensed

Compression Storage Pipework Dispenser

Hydrogen

(gaseous)

Cylinder /

tube trailer

/ on-site

generation Hydrogen

(gaseous) Optional Yes Yes Yes

Hydrogen

(liquid) Tanker

CNG Pipeline /

cylinders /

tube trailer

CNG Yes Yes Yes Yes

LNG Tanker LNG No Yes Yes Yes

Table 2: Typical components of a fuel filling installation

Where there is a desire to convert existing liquid-fuel dispense installations to gas fuel

dispensing (either as an exchange or both types together), the inherent hazards of the

various (and alternative) fuels with respect to buoyancy and ignition energy shall be

addressed through the DSEAR (14) risk assessment process.

NOTE: Such aspects will usually be significantly different to those encountered

when dealing with traditional liquid fuels alone. Consideration should be given to

unintentional releases, vents and leaks.

Forecourt design criteria for petrol filling stations can be obtained from the Petroleum

Enforcement Liaison Group (PELG), Petrol filling stations guidance on managing the

risks of fire and explosion (The Red Guide) (105) and the Blue Book (103 & 104).

Further information is available from the Energy Institute (EI) 15 (102), Model code of

safe practice Part 15: Area classification code for installations handling flammable

fluids.

NOTE: EI 15 (102) covers hydrogen installations in the context of refineries,

chemical plants, battery rooms and analyser houses.

Suitable access to all areas of the filling station for emergency personnel and equipment

shall be considered as part of the fire risk assessment. Refer to the Regulatory Reform

(Fire Safety) Order (15).

6.2 Location of storage installation

The location of storage vessels is often critical within a filling station layout. Storage

vessels are typically designed for external use; however, some components may require

weather protection. Wherever practicable, the storage installation should be located:

in an external area;

in an area that is secure;

where there is good natural ventilation;


where there are no sources of ignition, or where any potential sources of ignition are managed, for example, in compliance with DSEAR (14).

Other locations are discouraged but may be considered after a suitable and sufficient

risk assessment has been completed.

Cryogenic storage vessels for flammable fluids shall be located in accordance with and

conform to BCGA CP 46 (95).

Where location of storage vessels underground is essential, recommendations for

underground natural gas storage installations can be found in IGEM/UP/20 (99), ISO

16923 (56), IGEM UP/21 (100) and ISO 16924 (57). Recommendations for

underground hydrogen storage installations can be found in ISO/TS 20100 (64) and

EIGA Document 171 (89), Storage of hydrogen in systems located underground.

Where there are enclosed or semi-enclosed storage areas (for example, to provide

protection from the weather), they shall be constructed in such a way as to provide no

opportunity for the build-up of flammable gases in enclosed or confined spaces.

Requirements for ventilation shall be determined according to BS EN 60079-10-1 (68),

Explosive atmospheres - Part 10-1 - Classification of areas - Explosive gas

atmospheres, or equivalent guidance as part of the DSEAR (14) risk assessment process

with hazardous areas defined as appropriate. Consideration should be given to any

potential hazards or risks relating to the location and operation of the installation.

Different layout requirements may be necessary for each fuel according to their

physical properties. CNG is typically stored at pressures of 200 bar to 300 bar.

Hydrogen may be stored at significantly higher pressures, up to 1000 bar. Separation

distances should take into consideration the gas pressures used. LNG and liquid

hydrogen are stored at lower pressures, typically less than 20 bar. However, they are

stored at low temperatures with LNG around -162 °C and liquid hydrogen around

-253 °C. Filling stations for cryogenic liquids require unique layout considerations to

allow for the management of released vapour. The layout and design should consider

the effects of a release of a cryogenic liquid, such that any release can rapidly evaporate

and will have only a minimum effect on the storage tank supporting structure, such that

the storage tank will remain adequately supported.

This requirement, location, efficiency and access to connecting pipework shall be

considered during the early stages of concept design, refer to Section 6.5.

Gaseous hydrogen bulk storage installations shall conform to BCGA CP 33 (92).

Further information on compressed hydrogen storage can be found in NFPA 2 (109)

and NFPA 55 (111), Compressed gases and cryogenic fluids code, also ISO/TS 20100

(64).

LNG bulk storage installations shall conform to BCGA 46 (95). Further guidance is

available in IGEM UP/21 (100) and ISO 16924 (57).

Further guidelines for general practice can be found in EIGA Document 114 (87),

Operation of static cryogenic vessels, and BS EN ISO 21009-2 (65), Cryogenic vessels.

Static vacuum insulated vessels. Operational requirements.


Specific recommendations for liquid hydrogen storage can be found in EIGA

Document 6 (82). Further information for liquid hydrogen storage can be found in

NFPA 2 (109), NFPA 55 (111) and ISO/TS 20100 (64).

Specific recommendations for LNG storage installations can be found in BS EN 13645

(47). Further information for LNG storage installations can be found in IGEM/UP/21

(100), ISO 16924 (57), BCGA CP 46 (95) and NFPA 52 (110).

Physical separation of the storage installation from exposures or sources of hazard shall

be enforced to minimise the consequences of minor incidents. Consideration shall be

given to hazards arising from both flammable atmospheres and heat flux following

ignition. Consideration shall also be given to the method of delivery of fuel to the

storage installation. The DSEAR (14) risk assessment shall cover all hazards that may

arise during the delivery of fuel, and any additional control measures that may be

required during this period. Where necessary, guidance on vehicle impact protection is

included in Section 6.4. Consideration should also be given to impact avoidance for the

road tanker or mobile gaseous fuel trailer during offloading, and when the tanker or

trailer is parked (e.g. by using cones or possibly barriers). Vehicle refuelling whilst the

tanker or trailer is offloading should be justified by a suitable risk assessment. The

arrangements for delivery of fuels should be considered at an early stage, as this could

significantly increase the inventory at a site albeit it for a short period, and could

influence other aspects of the installation design (e.g. its floor -plan).

The separation distances in this document are intended as a guideline for both planning

authorities and system designers and installers. They are the minimum recommended

separation distances based upon generic considerations, which reflect both UK and

worldwide industry experience on design and installation of liquefied and compressed

flammable gas operations. It is the duty of the designer to ensure a comprehensive

viewpoint is given to separation distances at multi-fuel stations, including the differing

requirements for high-pressure ambient gaseous fuels and cryogenic liquid fuels.

Recommended minimum separation distances for hydrogen storage installations are

presented in Appendix 1. Where appropriate, these separation distances should be

applied both vertically and horizontally.

Recommended minimum separation distances for CNG and / or LNG storage

installations are presented in Appendix 2.

Based upon the details of a given installation it may be acceptable to reduce the

separation distances relative to those detailed in this document. Any reductions should

be justified based upon a site-specific risk assessment, or through the use of fire risk

modelling or standard mitigation factors (refer to the Blue Book (103 & 104) and

relevant industry documents).

The risk assessment shall specifically address the nature and use of adjacent property.

Recommended minimum separation distances may be extended where higher risks are

identified, for instance:

where the site is close to a heavily populated area;


where the site is close to a vulnerable population: school, hospital etc.;

where the site is remote from external help (such as the fire authority);

where existing site conditions may foreseeably change on either a temporary or permanent basis, i.e. change of use, future planning considerations,

increased personnel or maintenance activities.

If a bespoke safety case is required, guidance on a number of different methodologies

that exist for the determination of recommended minimum separation distances can be

found in EIGA Document 75 (86), Determination of safety distances, NFPA 2 (109)

and ISO/TS 20100 (64). It should be noted however that these methodologies may give

distances that are not consistent with the minimum separation distances recommended

by the BCGA.

In the event of a spill of a liquefied fuel gas, the liquid will both rapidly evaporate and

travel until it settles at the lowest point (before full evaporation). It is important to

ensure containment of the spill above ground in an area remote from personnel, where

the liquid can evaporate safely without presenting a risk of asphyxiation, cold burns,

ignition, or thermal shock to mechanical components. Vapour clouds which fail to

quickly disperse may be blown by the wind and in some circumstances may have a

potential to blow far beyond the site with a potential risk of asphyxiation or ignition.

Where liquefied fuel gas leaks may have entered confined spaces, appropriate measures

should be taken before personnel entry in accordance with the Confined Space

Regulations (8). The actions to be taken in the event of a spill should be clearly

identified, trained for, and included in the emergency response procedure, refer to

Section 14.

Consideration should be given to the appropriate use of civil engineering features for

risk mitigation, for example diversion kerbs or grading, to ensure that liquid leakage

from any adjacent hazardous store is prevented from accumulating in undesirable

locations (e.g. within the fuel gas store). When liquefied fuel gas storage is present,

measures should be employed to prevent spilled liquid fuel gas from flowing onto the

forecourt, onto cold-sensitive components (e.g. non-cryogenic rated storage vessel

support legs or skirts), into public areas or in the vicinity of other features, for example

drains, manholes, culverts, etc. which might lead to the creation of a hazard elsewhere,

in certain circumstances. The design and construction of the station base should allow

for the safe dispersal (e.g. evaporation) of liquid leakage. Options such as boil-off

pads, sloped surfaces, pits, walls, bunds etc. may be considered in this respect, noting

that other hazards may thereby be introduced and so any such proposal should be

validated by risk assessment. Further guidance is contained in BCGA CP 46 (95).

Where appropriate, storage areas shall be designed to be readily accessible to mobile

supply equipment, refer to Section 3.3 and to mobile service and safety equipment.

The liquid storage installation shall meet the requirements of BCGA CP 46 (95).

Fencing, civil engineering and general provisions for non-liquid installations shall

follow the same principles (such as buffer stores, compressor houses, etc.).


The minimum recommended separation distances of Appendix 1 and Appendix 2 shall

apply regardless of the position of the barrier or fence. If a fire resistant wall is used,

then by the methodology outlined in BCGA CP 4 (91), the safety distance may be

measured as the shortest distance around the ends of the wall to the storage installation.

An important principle in the hazardous area classification is the availability of

sufficient ventilation. The effect of firewalls can be to reduce ventilation, and this

should be considered in the site risk assessments. Firewalls shall provide a minimum of

30 minutes fire resistance in respect of integrity, insulation, and where applicable load

bearing capacity. Where the wall separates vulnerable populations from the dangerous

substance, the fire resistance provided shall be for a minimum of 60 minutes. Fire tests

are covered in BS 476 (37), Fire tests on building materials and structures.

If the storage area contains individual and / or bundles of cylinders, the layout shall be

designed to allow the use of suitable manual handling equipment and as appropriate,

forklift trucks.

Site areas where installations used for the production, storage and dispensing of

flammable liquids and gases and areas used for the delivery of fuels, shall not be

located beneath overhead electrical power lines. Installations shall be sited so that

damage to the installations or delivery vehicles by electric arcing from overhead or

other cables cannot occur.

6.3 Access and egress for fuel delivery vehicles

Access and egress may be required for delivery vehicles. For cryogenic flammable

fluids refer to BCGA CP 46 (95). Points for consideration include:

Protection of the tank(s) and pipes from vehicle impact, for example by barriers, bollards or kerbs. Guidance on vehicle impact protection is included in

Section 6.4;

Avoiding, wherever practical, the requirements for delivery vehicles to reverse;

Emergency arrangements for delivery vehicles and the delivery team; for example, requirements for the vehicle being able to drive away in a forward

direction without complex manoeuvring in the event of an emergency, subject to

the anti-drive-away provisions that should apply;

Hose lengths and hose handling arrangements; for example, parking post, storage space, purging, weather protection, capping, etc.;

Demarcation of the delivery vehicle parking location;

Signage, lighting and surface condition;

Drainage and spill arrangements from the delivery area;

The construction of the delivery pad surface, taking account of the actual delivery vehicle weight, size and layout;


Space (including height clearance) for use of cranes, fork-lift trucks or other accessories when making deliveries; for example, bundles of cylinders;

Restriction of access to the tanker stand when deliveries are being made;

Restriction of access to the tanker stand when deliveries are not being made;

Line-of-sight maintenance from vehicle control position to tank gauges and indicators;

Line-of-sight maintenance from station control position to the tanker stand;

The position of any sensors, alarms, alarm repeaters, indicators etc. for the use of the delivery team including the on-site competent person;

Electrical earthing and equi-potential bonding facilities (and any necessary signage and instructions);

Supply of nitrogen or dry air for road tanker discharge operation. Where relevant refer to BCGA CP 44 (94);

Special site rules which may need to apply during (and immediately before and after) deliveries;

The impact on the site zoning under DSEAR (14);

Security (such as measures to prevent unauthorised removal of the road tanker or trailer from the stand, i.e. to prevent theft);

Anti-drive-away provisions, to prevent damage to the installation (including hoses) in the event of tanker drive-away.

For fuel delivery, the tanker stand should be designed and managed exclusively for that

purpose. If the delivery operation cannot be contained within a secured area, temporary

demarcation and/or other reasonable means (e.g. cones) should be considered to restrict

public access during the delivery process.

At stations where multiple fuels are stored or dispensed, simultaneous bulk deliveries of

differing fuels should be prevented unless a suitable risk assessment determines

otherwise. Further information on the delivery requirements of other fuels is detailed in

the Blue Book (103 & 104).

HSE L133 (78), Unloading petrol from tankers. DSEAR. Approved Code of Practice

and guidance, whilst prepared for the delivery of petroleum products to filling stations,

contains relevant transferable information on principles appropriate to the risk

assessment and safe delivery of fuels to filling stations.


6.4 Location and installation of dispensing points

A specific area should be defined for vehicle fuelling. Wherever practicable,

dispensing equipment should be located outdoors in a freely ventilated area. Indoor

locations may only be considered after a suitable and sufficient risk assessment has

been completed. Further guidance for indoor hydrogen vehicle filling can be found in

NFPA 2 (109).

The location and proximity of dispensing equipment shall be established by risk

assessment. Based upon the details of a given installation it may be appropriate to

propose increased or reduced minimum separation distances relative to those detailed in

this document. Any reductions should be justified by, for example, the use of fire risk

and gas dispersion modelling or standard mitigation factors (refer to the Blue Book

(103 & 104) and other relevant industry documents). The minimum separation

distances within BCGA CP 4 (91) are recommended for the dispensing of gaseous

hydrogen. Once established, minimum separation distances and hazardous zone

requirements for additional dispensers and equipment shall be observed. For the

minimum recommended separation distances refer to Appendix 1 and Appendix 2.

Specialist storage and dispensing requirements for LNG shall be taken into

consideration when carrying out the risk assessment.

Where multiple dispensers are installed, e.g. for simultaneous refuelling, consideration

shall be given to the position of the dispensers and their proximity to planned or

existing dispensing equipment, storage and buildings, occupied and unoccupied.

When determining the location and positioning of dispensers consideration should be

given to traffic flow restrictions, traffic movements in the immediate vicinity of the

station, and the size and length of the vehicles to be refuelled. Measures to prevent

dangerous manoeuvres, for example, reversing into the path of traffic should be taken

when considering the design of the station and the location of dispensing points.

The vehicle fuelling area should be level, except for a minimal slope to aid surface

drainage.

Physical protection shall be provided to protect the dispenser from vehicular impact.

The characteristics of the specific vehicles to be fuelled at the installation should be

used to determine the civil engineering feature dimensions.

Height above the road

surface (mm)

Clearance between

dispenser and the edge of

the plinth (mm)

Stations serving light passenger

vehicles only 120 200

Stations serving heavy goods

and passenger-service vehicles 415 500

Table 3 – Typical dimensions for dispenser plinths


Dispensers shall be mounted on a plinth (or ‘island’) unless alternative physical

protection is employed. Table 3 provides guidance on typical dimensions for dispenser

plinths. The dimensions in Table 3 take into consideration the large diameter wheels of

Heavy Goods Vehicles (HGV) or Public Service Vehicles and the typical vehicle

overhang. If a station is being designed with specific vehicle types in mind, it may be

possible to establish exact vehicle dimensions and hence design the station and plinth

for those vehicles. Alternatively, suitable protection shall be provided to prevent

mechanical damage to all parts of the installation and associated pipework, for example

by the use of crash barriers or bollards. The type of vehicle expected to use the filling

station should be considered when specifying physical protection measures. Physical

protection arrangements for commercial vehicle filling may need to be more robust,

larger and with greater clearances than for light passenger vehicles.

Plinths should typically be of reinforced concrete construction, with suitable kerbs.

Vehicle restraints are covered in BS 7669 (42), Part 3, Vehicle restraint systems. Guide

to the installation, inspection and repair of safety fences.

Dispensers and associated equipment may be housed in enclosures. Such enclosures

may change the extent of the DSEAR (14) hazardous area. This may assist in the siting

of electrical equipment, refer to Section 3. However, this advantage may be at the

expense of the potentially explosive area within the enclosure, hence classification

inside the enclosure or housing shall be carried out, and appropriate electrical devices

installed, refer to Section 7.1.

As with other areas of the filling station, where new or existing electrical equipment is

within the hazardous area surrounding dispensing equipment, this equipment shall be

rated for the appropriate gas group(s), for example, group IIC for hydrogen.

If a canopy is provided over the dispensing area, refer to Section 7.9.

All electrical devices or lighting mounted within hazardous areas around or above the

dispenser shall be appropriately classified. Where the accumulation of flammable gas

or vapour cannot be avoided, the inclusion of gas detection equipment should be

considered. The gas detection system should automatically stop filling operations and

render the installation safe, in the event of gas detection. Refer to Section 7.1.

Dispensers shall be secured against unauthorised use and access control measures

should be considered, for example, swipe card readers. The fuel gas supply to the

dispenser shall be capable of being isolated. To prevent unauthorised or inadvertent re-

activation of isolated services it is strongly recommended that the isolation point is in a

secure location. Where the isolation point is in an area accessible to the public or

unauthorised parties outside operating hours, it shall be fitted with appropriate security

devices.

6.5 Connecting pipework

Manifolds and fuel gas distribution pipework shall comply with the requirements of

BCGA CP 4 (91). CNG installation connections to gas supply network pipework and

manifolds shall conform to the requirements of IGEM UP/20 (99). Further guidance

for CNG storage as part of a vehicle filling station can be found in ISO 16923 (56) and


NFPA 52 (110). The material of construction shall be compatible with the gas,

pressure and temperature.

Wherever practicable, the connecting pipework between production, storage and

dispensing equipment should be located in the open air. Where dispensers (especially

for cryogenic services) are located on remote dispenser islands pipework should be laid

in suitably constructed ducts.

All pipework shall be accessible to facilitate periodic inspection, examination and/or

testing.

Where there is a requirement to maintain the product as a cryogenic liquid then

pipework should be insulated, for example vacuum insulated, and kept as short and as

straight as is reasonably practical. This will assist in minimising boil-off.

Pipework should be marked with the pipe contents, and if possible the flow direction

and pressure and be colour coded. Where pipework is protected by insulation materials

then the identification markings are to be on the outside of the insulation.

6.6 On site fuel generation equipment and related process equipment

Fuel generation equipment shall be installed and operated according to the

manufacturer’s recommendations.

Where the equipment is fully enclosed, for example, for weather protection,

requirements for explosion relief shall be considered as part of the risk assessment.

Access is to be restricted to authorised personnel.

6.7 Vent systems

All gaseous fuels within the scope of this code are stored and used under pressure. As

such they are fitted with over pressure protection devices to release excess pressure

under normal operating conditions and in emergency situations such as fire. Manually

operated valves may also be fitted to release pressure, for example, for maintenance.

When these devices operate any product that is subsequently vented shall be dispersed

safely to reduce the risk of accumulation, ignition, or impingement on personnel,

equipment and buildings. This shall be achieved by the use of a vent system where the

product is released via a remote vent stack.

For information on the design, installation and marking of vent stacks installed for

cryogenic flammable fluids refer to BCGA CP 46 (95) and EIGA 211 (90), Hydrogen

vent systems for customer applications.

6.8 Vent recovery

Consideration shall be given to vent recovery and the prevention of boil-off gas

escaping from LNG vehicles and static equipment during the refuelling process, for

example, through the use of vapour recovery or vapour management equipment. Refer

to ISO 16924 (57).


6.9 Other filling station activities

Consideration should be given to the layout of the filling station with relation to

vehicular and pedestrian movements arising from all other foreseeable filling station

activities, for example, petrol / diesel / LPG dispensing and deliveries, shop, tyre

inflation, car wash, customer parking etc. As far as is reasonably practicable, activities

unrelated to vehicle filling should be located outside of hazardous areas and vehicles

and pedestrians should not have to pass through hazardous areas to get to those

activities. The recommended minimum separation distances should be maintained.

Access requirements for personnel, plant and equipment shall be taken into

consideration for operational, maintenance, inspection, testing and decommissioning

activities.

Large vehicles should not have to perform complex manoeuvres and the site should be

designed and laid-out to facilitate this. An awareness should be maintained of

pedestrian movements around the installation, in order that hazards (for example, due to

driver’s blind-spots) may be minimised.

7. DESIGN OF FILLING STATION

7.1 General

The filling station shall be designed to minimise risk to users, operating personnel,

general public, nearby properties and the environment, as well as taking account of any

security requirements. This is referred to as safety by design; a concept which

incorporates fail-safe mechanisms, features and philosophy.

Commonly, potential methods of failure, the associated consequences and mitigating

safeguards are explored through a combination of risk identification and assessment

methodologies including DSEAR (14) risk assessments, Hazard and Operability

Studies (HazOpS or HAZOPS), Failure Mode and Effect Analysis (FMEA) and Layer

of Protection Analysis (LOPA). Where in-scope safety instrumented systems are

present, consideration shall be given to applying Safety Instrumented System (SIL)

techniques in accordance with BS EN 61511 (71), Functional safety. Safety

instrumented systems for the process industry sector. Specific and more detailed

information can be obtained from BS EN 61508 (70), Functional safety of electrical /

electronic programmable electronic safety related systems.

Designers engaged and involved in the outline definition, detailed design, specification,

installation and commissioning of installations in the scope of this document shall be

suitably competent and shall have experience in the relevant field(s). Table 4 provides

a guide to the competence requirements for Designers of specific types of installation.

The appropriate level of reliability of control and safety systems should be determined

through appropriate analysis and suitable risk assessment.


Fuel

Storage

Competence and experience required in the fields of:

Compressed

gases Liquefied

cryogenic

gases

Flammables

including

ATEX/DSEAR

Pressure

systems

engineering

Fuel

dispense

equipment

Hydrogen

(gaseous) Y

N (unless liquid

is present) Y Y Y

Hydrogen

(liquefied) Y Y Y Y

Y (if in scope)

CNG Y N

(unless liquid

is present) Y Y Y

LNG Y Y Y Y Y

Table 4: Competence and experience guide

The installation shall have appropriate automated safety shutdown and isolation

capabilities and easily accessible manual emergency shutdown devices. For LNG

automated shutdown and isolation capabilities refer to ISO 16924 (57). Due regard

shall be given to the combination of shutdown and isolation functions for all other

hazardous products, systems and services on the filling station site, including

appropriately positioned emergency switching devices in accordance with the Blue

Book (103 & 104). Safety circuitry should be hard wired using suitable latching relays

or via a safety validated BS EN 61508 (70) compliant computer control system(s).

The design shall comply with DSEAR (14) (taking into account fuel buoyancy), the

PSSR (11) and, where appropriate, shall be CE marked to the relevant applicable

European Directives, such as:

The Pressure Equipment Directive, European Directive 2014/68/EU (PED) (34), implemented in the UK through the Pressure Equipment (Safety)

Regulations (21);

The Machinery Directive, European Directive 2006/42/EC (26);

The Low Voltage Directive, European Directive 2014/35/EU (33);

The Electromagnetic Compatibility Directive, European Directive 2014/30/EU (32);

DSEAR (14) / ATEX European Directive 99/92/EC (25);

European Directive 2009/104/EC (27) the Use of Work Equipment Directive for minimum health and safety requirements for the use of work

equipment by workers at work, implemented in the UK through PUWER (9).


The design shall protect against hazards associated with loss of containment of fuel.

The designer should typically consider the following:

Minimising the number of potential release points and reducing the likelihood of release.

Ventilation to maximise dilution of leaked fuel, hence keeping any resulting mixtures below flammable limits and avoiding the build-up of potentially

explosive atmospheres or the risk of asphyxiation in confined spaces. Refer to

the Confined Spaces Regulations (8).

Fuel leak detection, refer to:

o BS EN 60079 (68) Part 29, 1 to 4, Explosive atmospheres. Gas detectors;

o Hydrogen sensing, BS ISO 26142 (67), Hydrogen detection apparatus. Stationary applications;

o Use of LNG low temperature sensors, ISO 16924 (57) to indicate product loss.

Emergency shutdown system(s), as appropriate.

Hazardous area classification including of potential leak points, vents (and any hazards arising from these vents) and drains.

Ignition protection, earthing and bonding to prevent static (and other) charge build-up.

Mitigation against the effects of ignition, for instance blast walls, explosion relief, fire protection, etc.

A major concern associated with the storage and dispensing of all vehicle fuels is the

risk of fire and explosion. Both electrical and mechanical equipment can be a source of

ignition.

The probability of a fire and explosion hazard is reduced by the provision of good

design and layout, as well as appropriate operating and maintenance procedures.

Generally there are two elements to fire risk assessment. The first is the special,

technical and organisational measures which, in respect of fuel stations, are essentially

the precautions required to prevent the outbreak and rapid spread of a fire or explosion

due to work activities concerning the receipt, storage and dispensing of vehicle fuels.

Secondly, appropriate measures need to be taken to address ‘everyday’ or general fire

risks. These include those measures necessary to prevent fire and restrict its spread and

those measures necessary in the event of outbreak of fire, to enable those present

(including the general public) to safely evacuate the premises.

These general fire precautions include the means for detecting fire and giving fire

warning, the means for fire-fighting, the means of escape, ensuring escape routes can


be used safely and effectively by employees and members of the public visiting the site,

and the competence of employees in fire safety. The presence of a variety of different

fuel types, comprising a blend of flammable components with differing properties

including those soluble in water, may influence the form and consequences of any fire

and therefore the required range of the general fire precautions. It is of critical

importance that the presence of dangerous substances is taken into account in

determining the general fire precautions necessary. A fire risk assessment shall be

carried out in accordance with the Regulatory Reform (Fire Safety) Order (15). Fire

protection equipment shall be provided as required by the site fire risk assessment.

In hydrogen and high purity natural gas (LNG and CNG) installations consideration

should be given to the detection of a fire. When their flames burn they can be (in

daylight) difficult to detect by eye. The use of technologies, such as thermal imaging,

will be advantageous.

Other flammable substances and combustible materials shall not be stored or be

allowed to accumulate in the vicinity of the storage or dispensing areas.

Electrical installations shall as a minimum, conform to BS 7671 (43), Requirements for

electrical installations. IET wiring regulations.

All fixed electrical equipment located in hazardous zones shall have the appropriate

ATEX rating, refer to BS EN 60079 (68), Explosive atmospheres. Part 14, Electrical

installations design, selection and erection, taking into account the relevant gas group(s)

classification.

Where gaseous fuels and traditional fuels are dispensed at the same filling station,

mandatory requirements for electrical installations are detailed in the Blue Book (103 &

104).

Where applicable, electrical equipment which is necessary for the installation shall be to

BS EN 60529 (61), Specification for degrees of protection provided by enclosures,

protection class IP54 or better. For more severe environmental conditions protection class

IP55 (designed to protect against water jets) should be used.

Lightning protection may be necessary to comply with local conditions or site

regulations. Lightning protection should be considered and implemented as

appropriate, refer to BS EN 62305 (72), Protection against lightning.

Conductive parts (e.g. metal fitments) on the installation including fencing, gates,

tanks and all pipework, vent stacks and vent recovery hoses, shall be adequately equi-

potential (earth) bonded. Refer to BS 7430 (41), Code of practice for protective

earthing of electrical installations.

Where gas detection is identified as necessary within the risk assessment, a suitable gas

detection system is to be fitted. For information on gas detectors refer to BS EN 60079

(68), Explosive atmospheres – Part 29-2: Gas detectors – Selection, installation, use

and maintenance of detectors for flammable gases and oxygen.


The locations for the gas detection equipment shall take into account the physical

properties of the respective gases, potential release points and areas where they may

accumulate.

Audio / visual alarms, along with appropriate warning notices, safety signs and

instructions, shall be positioned at strategic locations within the area and at control

centres, as determined by the risk assessment. Alarm levels are to be set to allow action

to be taken in the event of a release of product, providing an early warning system, but

not such that it creates false alarms; thus allowing time for personnel to evacuate the

area before hazardous conditions are reached i.e. flammability range and/or workplace

exposure limits are reached.

Detection equipment should be installed, maintained and tested in accordance with the

manufacturer’s recommendations. Alarms should be tested regularly.

All systems should be fail safe and programmable devices should have an appropriate

SIL (Safety Integrity Level) rating. The gas detection system and/or any process

control system, may interface with the emergency shut-down system.

Adequate lighting shall be provided to allow for the identification of the product(s)

(signage and labels), to allow normal operations, maintenance, manual handling

activities and deliveries to be undertaken safely, as well as to assist with security. The

light source used shall give suitable colour rendering to enable colour labelling to be

easily recognised by persons with normal colour vision. Lighting is required to be

appropriately located, lighting equipment and ancillaries shall be suitably rated for the

hazardous area (if any)