IGEM/UP/12 Edition 2 with Amendments 2009

Communication 1832

Application of burners and controls to gas

fired process plant

Founded 1863
Royal Charter 1929
Patron: Her Majesty the Queen
IGEM/UP/12 Edition 2
Communication 1832

Application of burners and controls to gas

fired process plant

Price Code: C5H

© The Institution of Gas Engineers and Managers
IGEM House
High Street
Kegworth
Derbyshire, DE74 2DA
Tel: 0844 375 4436
Email: technical@igem.org.uk
Copyright © 2019, IGEM. All rights reserved
Registered charity number 214011

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 978-1-9996747-8-6
Published by the Institution of Gas Engineers and Managers

Previous Publications:
Communication 1713 (2006) – 1st Edition
Communication 1778 (2015) – 2nd Edition

For information on other IGEM Standards please visit our website, www.igem.org.uk
IGEM/UP/12 Edition 2 with Amendments 2009

CONTENTS

SECTION PAGE

1 Introduction 1

2 Scope 4

3 Legislation and Standards 6

 3.1 Health and Safety at Work etc. Act (HSWA) 6

 3.2 Building Regulations 6
 3.3 Confined Spaces Regulations 7
 3.4 Construction (Design and Management) Regulations
(CDM) 7
 3.5 Control of Asbestos at Work Regulations 7
 3.6 Control of Substances Hazardous to Health Regulations
(COSHH) 8
 3.7 Dangerous Substances and Explosive Atmospheres Regulations 8
 3.8 Gas Safety (Installation and Use) Regulations (GS(I&U)R) 8
 3.9 Gas Safety (Management) Regulations (GS(M)R) 9
 3.10 Management of Health and Safety at Work Regulations
(MHSWR) 9
 3.11 Pressure Equipment Directive (PED) 10
 3.12 Pressure Systems Safety Regulations (PSSR) 10
 3.13 Provision and Use of Work Equipment Regulations (PUWER) 11
 3.14 Reporting of Injuries, Diseases and Dangerous Occurrences
Regulations (RIDDOR) 11

4 General 13

5 Gas supplies 15

 5.1 Filters and strainers 15

 5.2 Pipework 15
 5.2.1 General 15
 5.2.2 Flexible pipes 15
 5.2.3 Purge and test points 16
 5.2.4 Gas boosters, compressors and pre-mix machines 17
 5.3 Gas pressure 17
 5.4 Manual valves 17
 5.5 Gas supply controls 18
 5.5.1 Non-return valves (NRVs) 18
 5.5.2 Pressure regulators 19
 5.6 High and low gas pressure protection 19
 5.6.1 High gas pressure protection 19
 5.6.2 Low gas pressure protection 20
 5.7 Air/gas mixtures (pre-mix systems) 20

6 Chimneys/flues, combustion and ventilation air supplies 22

 6.1 General 22
 6.2 Mechanical ventilation 22

IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk
IGEM/UP/12 Edition 2 with Amendments 2009

 6.3 Mechanically supplied combustion air 22

 6.4 Chimney or flue/extract systems 24

7 Ancillary supplies 25

 7.1 Electricity 25
 7.2 Instruments and control fluids 26

8 The system 27

 8.1 General 27
 8.2 Flame detection 28
 8.2.1 General 28
 8.2.2 Flame detection 28
 8.2.3 Flame safeguard systems – general 29
 8.2.4 Thermo-electric flame safeguard systems 29
 8.2.5 Self-checking flame safeguards 29
 8.2.6 Flame safeguards for pilot burners 30
 8.2.7 Flame safeguards for low temperature plant 30
 8.2.8 Flame safeguards for high temperature plant 30
 8.3 Pre-purge or ventilation 32
 8.3.1 General 32
 8.3.2 Forced and induced draught systems 33
 8.3.3 Natural draught systems 34
 8.3.4 Post-purge or ventilation 34
 8.4 Ignition and start-gas flame establishment 34
 8.4.1 General 34
 8.4.2 Lighting torches 34
 8.4.3 Electric spark ignition 35
 8.4.4 Start-gas flame 35
 8.4.5 Pilots 36
 8.5 Establishment of the main flame 37
 8.6 Safety shut-down systems 38
 8.6.1 General 38
 8.6.2 Main burner 39
 8.6.3 Start-gas 40
 8.6.4 Lighting torches 41
 8.6.5 SSOV closure 41
 8.7 Vent valves 42
 8.8 Other interlocks 42
 8.8.1 Excess temperature 42
 8.8.2 Plant extract and re-circulation fans 43
 8.8.3 Conveyor ovens and furnaces 43
 8.9 Throughput and fuel/air ratio control 43
 8.10 Commissioning and testing 45

9 Shut-down 46

 9.1 General 46
 9.2 Shut-down checks 46

10 Further procedures for dual fuel, multi-fuel and combination firing 48

 10.1 Oil fuels 48

 10.2 LPG, LPG-air and other gaseous fuels 48

IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk
IGEM/UP/12 Edition 2 with Amendments 2009

 10.3 Systems 49
 10.3.1 Flame detection 49
 10.3.2 Ignition and start-gas flame establishment 49
 10.3.3 Safety shut-off systems 49
 10.4 Fuel/air ratio control 49

11 Overpressure protection 50

 11.1 Failure of the gas supply (meter) regulator 50

 11.2 Failure of the throughput control valve 50
 11.3 Failure of the plant regulator 50

12 Specialised process plant and burner systems 51

 12.1 Plant involving the use of flammable solvents and materials 51

 12.2 High temperature plant in schools, colleges and arts/craft
establishments 51
 12.3 Ceramic kilns and equipment operating with gas rich
atmospheres 51
 12.4 Catalytic radiant panels 52

13 Ancillary information and equipment 54

 13.1 General 54
 13.2 Design data 54
 13.3 Marking 54
 13.4 Commissioning data 55
 13.5 Operating data 55
 13.6 Viewing ports 55
 13.7 Fuel metering 55
 13.8 Combustion quality 56
 13.9 Explosion reliefs 56

14 Servicing, maintenance and burner replacement 57

 14.1 General 57
 14.2 Retro-fitting of new burners to existing plant 57
 14.2.1 Burners and controls 57
 14.2.2 Gas supply and pipework 58

APPENDIX

1 Glossary, acronyms, abbreviations, symbols and units 59

2 References 61

3 Protection against plant regulator failure 65

4 Description of SSOV systems 66

5 Leak tightness testing of gas SSOV systems 67

6 Start-up, switchover and operating sequences 71

IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk
IGEM/UP/12 Edition 2 with Amendments 2009

7 Safety aspects of multi-firetube boiler firing 79

8 Explosion relief 81

9 Pulse firing systems 88

10 Purging of large volume plant 89

11 Weep by-pass pressure proving systems 91

12 Oxygen and oxygen assisted combustion systems 97

13 Protection against reverse pressurisation 103

FIGURES

1 Operational pressure limits 2

2 Typical schematic burner layout 14

3 Typical multi-burner SSOV layouts 28

4 Typical high temperature burner layout with weep by-pass proving 31

5 Typical sequential valve proving arrangement 39

6 Typical pressure valve proving arrangement 40

7 A typical three valve system 40

8 Interlocked switch system 69

9 Interlocked plug and socket system 70

10 Typical explosion panel construction 83

11 Explosion relief positions for conveyor ovens 86

12 Minimum spacing from walls for plant of volume exceeding 5 m 3 87

13 Typical layout for a weep by-pass proving system 91

14 Typical limiting orifice 92

15 Low pressure cut-off valve 94

TABLE

1 Response time for loss of flame for self-checking flame safeguards 30

2 Typical volumes within one half of a valve body 68

3 Limiting pressures and velocities for pipe materials 98

IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk
IGEM/UP/12 Edition 2 with Amendments 2009

SECTION 1 : INTRODUCTION

1.1 This Standard supersedes IGE/UP/12, Communication 1713, which is obsolete.

1.2 This Standard has been drafted by an Institution of Gas Engineers and Managers
(IGEM) Panel, appointed by IGEM’s Gas Utilization Committee and has been
approved by IGEM’s Technical Co-ordinating Committee on behalf of the Council
of IGEM.

1.3 It is recognised that many combustion systems use forced draught burners that
comply with BS 5885 and BS EN 676. Such installations now have to comply with
BS EN 746-2 and this Standard covers all such systems, as well as those using
full pre-mix, partial pre-mix and natural draught aeration systems.

1.4 This Standard embraces the major requirements of the withdrawn Health and
Safety Executive (HSE) publication HS(G)16.

1.5 It is important that those involved in the design, installation and maintenance of
gas-fired plant are competent and suitably trained to ensure safety. In general,
process plant is not in the scope of the Gas Safety (Installation and Use)
Regulations (GS(I&U)R). However, compliance with the intent of GS(I&U)R is
recommended. In this respect, employers’ attention is drawn to the requirements
of IGEM/IG/1.

1.6 It is recognised that many items of existing plant may not comply with current
Standards. This Standard may be used as a basis for updating. The degree of
updating will depend upon the capital available and the risks associated with the
operation of the plant.

1.7 As far as is practicable, gas fired plant needs to be fitted with flame safeguards
and the fuel/air ratio controlled such that rich firing does not occur. For high
temperature plant where the operating temperature exceeds 750°C and flame
protection is not practicable, a minimum of a weep by-pass pressure proving
check (see Appendix 11) is recommended.

1.8 Terms such as “maximum operating pressure” (MOP), “maximum incidental

pressure” (MIP) and “operating pressure” (OP) “lowest operating pressure”
(LOP) and “design minimum pressure” (DmP) were introduced in IGEM/UP/2
Edition 2 to reflect gas pressure terminology used in European standards.

Other terms were introduced to assist in recognition of design information to be

transferred between interested parties.

Referring to Figure 1, attention is drawn to how operating pressure oscillates

about the set point (SP). Note also that MOP can be declared at a higher value
than OP. The strength test pressure (STP) has to exceed MIP. This means that,
at least with respect to integrity, the installation will withstand a fault pressure
from the upstream system. Safe operating limit (SOL) is a requirement of the
Pressure Systems Safety Regulations (where applicable).

1
IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk
IGEM/UP/12 Edition 2 with Amendments 2009

SOL
MIP

STP = Strength test pressure

SOL = Safe operating limit
MIP = Maximum incidental pressure
MOP = Maximum operating pressure
SP = Maximum set point of, typically, the active regulator
OP = Operating pressure.

FIGURE 1 - OPERATIONAL PRESSURE LIMITS

This Standard makes use of the terms “must”, “shall” and “should” when
prescribing particular requirements. Notwithstanding Sub-Section 1.12:
 the term “must” identifies a requirement by law in Great Britain (GB) at the
time of publication
 the term “shall” prescribes a requirement which, it is intended, will be
complied with in full and without deviation
 the term “should” prescribes a requirement which, it is intended, will be
complied with unless, after prior consideration, deviation is considered to be
acceptable.

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.

1.9 The primary responsibility for compliance with legal duties rests with the
employer. The fact that certain employees, for example “responsible engineers”,
are allowed to exercise their professional judgement does not allow employers to
abrogate their primary responsibilities. Employers must:
 have done everything to ensure, so far as it is reasonably practicable, that
“responsible engineers” have the skills, training, experience and personal
qualities necessary for the proper exercise of professional judgement
 have systems and procedures in place to ensure that the exercise of
professional judgement by “responsible engineers” is subject to appropriate
monitoring and review
 not require “responsible engineers” to undertake tasks which would
necessitate the exercise of professional judgement that is not within their
competence. There should be written procedures defining the extent to which
“responsible engineers” can exercise their professional judgement. When
“responsible engineers” are asked to undertake tasks which deviate from this,
they should refer the matter for higher review.

1.10 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 actions by people initiated or contributed to the accidents, or people might
have acted in a more appropriate manner to avert them.

2
IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk
IGEM/UP/12 Edition 2 with Amendments 2009

It is therefore necessary to give proper consideration to the management of these

human factors and the control of risk. To assist in this, it is recommended that
due regard be paid to HSG48 and HSG65.

1.11 Notwithstanding Sub-Section 1.9, this Standard does not attempt to make the
use of any method or specification obligatory against the judgement of the
responsible engineer. Where new and better techniques are developed and
proved, they ought to be adopted without waiting for modification to this
Standard. Amendments to this Standard will be issued when necessary, and their
publication will be announced in the Journal of the Institution and other
publications as appropriate.

1.12 Requests for interpretation of this Standard in relation to matters within its scope,
but not precisely covered by the current text, need to be addressed in writing to
Technical Services, IGEM, IGEM House, High Street, Kegworth, Derbyshire,
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 the engineer
concerned. If any advice is given by or on behalf of IGEM, this does not relieve
the responsible engineer of any of his or her obligations.

1.13 This Standard was published in August 2019.

1.14 Amendments are shown throughout the document by 

3
IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk
IGEM/UP/12 Edition 2 with Amendments 2009

SECTION 2 : SCOPE

2.1 This Standard provides the minimum requirements for combustion systems in
respect of safety in start-up, operation and shut-down of gas-fired process plant.
It does not provide a complete specification for burners, plant and control
equipment.

2.2 This Standard applies to the use of gas in plant in industrial and commercial
premises and nothing in this Standard implies any requirement for burners or
appliances for other applications, for example for gas turbines (see IGE/UP/9) or
for appliances constructed to recognised European standards such as hot water
boilers and air heaters for space heating.

2.3 This Standard applies to relevant plant using Natural Gas (NG). It may also be
applied for other gases and fuels where no other guidance is available, provided
due allowance is made for the different combustion qualities and fuel
characteristics.

2.4 This Standard applies to dual fuel and multi-fuel plant when operating on NG.
Further advice on dual fuel and multi-fuel firing is given in Section 10.

2.5 It is recognised that, for specialised gas fired processes, it is permissible to use
procedures which differ from those given in this Standard but which, nevertheless,
comply with the intent. Similarly, new systems or procedures resulting from
advances in technology may be applied to give equal or improved safety. It is not
intended that this Standard prohibit the development or use of such systems, but
any departure from this Standard is not recommended except when on the basis
of sound engineering judgement, experience and subject to a risk assessment.

2.6 This Standard does not apply to:

 burners firing in the open and under constant manual supervision, for example
Bunsen burners, gas rings, small open ended furnaces, etc.
 small industrial plant and appliances of heat input not exceeding 7.5 kW
(25000 Btu/h), for example soldering irons, glue pots, small lead pots
 burners, appliances or plant covered by specific manufacturing standards, for
example BS 5885, BS 5990 and BS 5978. However, they do include application
requirements for such burners when applied to process plant
 plant covered by specific British or European manufacturing standards, for
example BS EN 676. However, they do include the application of such plant
 heating plant such as boilers and air heaters supplied complete with matched
burners
 gas turbines, for which reference should be made to IGE/UP/9
 spark ignition and dual-fuel engines, for which reference should be made to
IGEM/UP/3 Edition 2
 the distribution and use of protective atmosphere gases, for which reference
should be made to BS EN 746-3. However, for atmosphere gas burner control
and safety systems, this Standard applies.

2.7 This Standard assumes that plant is designed and installed in accordance with
good engineering practice and having due regard to GS(I&U)R and the
Management of Health and Safety at Work Regulations (MHSWR).

2.8 Gas-fired process plant is required to comply with the Supply of Machinery
(Safety) Regulations and, where appropriate, the requirements of the Pressure
Systems Safety Regulations (PSSR) and the Dangerous Substances and Explosive
Atmospheres Regulations (DSEAR).

4
IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk
IGEM/UP/12 Edition 2 with Amendments 2009

In general, The Gas Appliances (Safety) Regulations are not relevant as they apply
to appliances for cooking, heating, hot water production (at temperatures not
exceeding 105°C) refrigeration, lighting and washing. Appliances designed for
industrial processes on industrial premises are also excluded from the scope of
the Regulations. Certain process plant, such as hot water boilers not specifically
designed for process applications but used in conjunction with process equipment,
may fall within the scope of the Regulations.

2.9 This Standard applies to both high temperature plant (defined as having a normal
working temperature sufficient to ignite the fuel, that is above 750°C at the
working chamber walls) and low temperature plant (defined as having a normal
working temperature at or below 750°C). High temperature plant will also
operate in the low temperature mode at some time in its operation and this has
to be taken into account when assessing safety issues.

2.10 This Standard applies to new plant and it is not the intention to apply any
requirements retrospectively. However, if existing plant is being upgraded, it is
recommended that the intent of this Standard is to be followed as far as possible.
A risk assessment is to be made whenever any changes are proposed for any
plant (see IGE/SR/24).

2.11 All pressures are gauge pressures unless otherwise stated.

2.12 All heat inputs are net heat inputs unless otherwise stated.

2.13 Italicised text is informative and does not represent formal requirements.

2.14 Appendices are informative but can represent formal requirements if referred to
via the prescriptive terms “should”, “shall” or “must”.

5
IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk