Technical Bulletin 159

Technical Bulletin 159 Developed by BSI, IGEM, HHIC and Progressive Energy

Natural gas standards when working on domestic installations being supplied with natural gas containing up to 20 vol% hydrogen Date issued: 23 March 2021

This Technical Bulletin provides guidance to Gas Safe registered businesses and engineers related to the impact on working practices when undertaking activities on domestic natural gas installations being supplied with natural gas containing up to 20 vol% hydrogen.

Background

Following research undertaken by the HyDeploy project(1), all IGEM and BSI standards that underpin ACS natural gas domestic and commercial competencies were reviewed; this review related to the potential impacts of a 20 vol% hydrogen blend on public safety and the function of appliances and domestic gas installations. The review process was carried out by Blue Flame Associates working in collaboration with the HyDeploy Consortium (Note 1).

The review(2) of standards was further peer reviewed by the Institution of Gas Engineers and Managers (IGEM), the British Standards Institution (BSI), the Heating and Hot Water Industry Council (HHIC) and the gas industry Standards Consultation Forum (SCF). The conclusions of the review as it relates to domestic installations and appliances form the basis of this Technical Bulletin.

Review process

As part of the HyDeploy project, an expert group of technical and procedural specialists collated and reviewed all BSI and IGEM procedures that underpin natural gas competencies for domestic and commercial working practices. The purpose of this Technical Bulletin is to detail the output of the review as it relates to domestic working practices. Technical areas assessed included: 1. Chimney/flue design 2. Ventilation design 3. Seals and gaskets 4. Combustion analysis* 5. CO detection 6. Leak detection fluids 7. Proving devices 8. Pipework installation 9. Tightness testing & purging 10. Gas meters, including heat input calculations 11. Excess flow valves 12. Flame arrestors 13. Temperature exposure 14. Appliance installation and maintenance 15. Commissioning

* Technical detail on the applicability of combustion analysers and their associated performance criteria can be found in Technical Bulletin 157(3) .

In total, 57 standards were reviewed and a total of 83 technical questions were generated; these questions related to the potential impact of a 20 vol% hydrogen blend on the routine application of the standard by a Gas Safe registered engineer. All questions were issued to an expert technical group of the HyDeploy Consortium to provide supporting evidence of any implications. An iterative process of review and discussion was undertaken to agree the impact that a 20 vol% hydrogen blend would have on all aspects of the standards reviewed.

Following the preliminary review, a second peer review was undertaken by a mixture of industry experts, including both standard setting bodies, BSI and IGEM: 1. IGEM Gas Utilisation

Committee 2. IGEM Hydrogen Committee 3. BSI GSE/30 – Gas

Installations (1st, 2nd and 3rd family gases) Committee 4. A select group of manufacturers and installers (HHIC), and 5. Members of the Standards

Consultation Forum (SCF).

The peer review process generated an additional 69 comments/questions, which were further addressed and the final conclusions issued to IGEM and BSI.

Conclusion

The review demonstrated that no change to domestic natural gas standards is required to account for the impacts associated with the introduction of a 20 vol% hydrogen blend within natural gas supplies. No additional measures, guidance or actions are necessary to account for the potential presence of a blend of hydrogen up to 20 vol% within natural gas supplies for domestic installations and appliances.

A minority of technologyspecific commercial areas remain for possible future study (eg, internal combustion gas engines, CNG filing stations) and these will be addressed during future investigations.

BSI Standards reviewed

BS 715: 2005 Specification for metal flue boxes for gas-fired appliances not exceeding 20kW BS 5440: Flueing and ventilation for gas appliances of rated input not exceeding 70kW net

Part 1: 2008 Specification for installation of gas appliances to chimneys and for maintenance of chimneys

Part 2: 2009 Specification for the installation and maintenance of ventilation provision for gas appliances BS 5546: 2010 Specification for installation and maintenance of gas fired water heating appliances of rated input not exceeding 70kW net. BS 5864: 2019 Installation and maintenance of gas fired ducted air heaters of rated input not exceeding 70kW net – Specification BS 5871: Specification for installation of gas fires, convector heaters, fire/back boilers and decorative fuel-effect gas appliances

Part 1: 2005 Gas fires, convector heaters, fire/back boilers and heating stoves

Part 2: 2005 Inset live fuel effect gas fires of heat input not exceeding 15kW, and back boilers

Part 3: 2005 Decorative fuel effect gas appliances of heat input not exceeding 20kW

Part 4: 2007 Independent gas-fired flueless fires, convector heaters and heating stoves of nominal heat input not exceeding 6kW BS 6172: 2019 Specification for installation, servicing and maintenance of domestic gas cooking appliances BS 6173: 2009 Specification for installation and maintenance of gas fired catering appliances for use in all types of catering establishments BS 6230: 2011 Specification for installation and maintenance of gas fired forced convection air heaters for commercial and industrial space heating BS 6400: Specification for installation, exchange, relocation, maintenance and removal of gas meters with a maximum rated capacity not exceeding 6m3/h.

Part 1: 2016 Low pressure (2nd family gases)

Part 2: 2018 Medium pressure BS 6644: 2011 Specification for the installation and maintenance of gas-fired hot water boilers of rated inputs between 70kW (net) and 1.8MW (net) (Incorporating Corrigendum No. 1)

BS 6798: 2014 Specification for selection, installation, inspection, commissioning, servicing and maintenance of gas fired boilers of rated input not exceeding 70kW net BS 6891: 2015 Specification for the installation and maintenance of low pressure gas installation pipework of up to 35 mm (R1¼) on premises (Incorporating Amendment No. 1) BS 6896: 2011 Specification for installation and maintenance of gas-fired overhead radiant heaters for industrial and commercial heating BS 7624: 2004 Installation and maintenance of domestic direct gas fired tumble dryers of up to 6kW heat input – Specification BS 7967: 2015 Guide for the use of electronic portable combustion gas analysers for the measurement of carbon monoxide in dwellings and the combustion performance of domestic gas fired appliances BS 8446: 2005 Specification for the installation and maintenance of open flued, non-domestic gas fired laundry appliances BS 8660: 2011 Gas-fired micro-cogeneration appliances of rates thermal input not exceeding 70kW net

Part 1: 2011 Specification for selection, installation, inspection, commissioning, servicing and maintenance of

Stirling engine microcogeneration appliances BS EN 161: 2007 Automatic shutoff valves for gas burners and gas appliances

IGEM Standards reviewed

IGE/UP/1: Edition 2 Strength testing, tightness testing and direct purging of industrial and commercial gas installations (Reprint with Amendments) IGE/UP/1A: Edition 2 Strength testing, tightness testing and direct purging of small, low pressure industrial and commercial natural gas installations (Reprint with Amendments)

IGEM/UP/1B: Edition 3

Tightness testing and direct purging of small liquefied petroleum gas/air, natural gas and liquefied petroleum gas installations (Incorporating Amendments)

IGEM/UP/1C: Edition 1

Strength testing, tightness testing and direct purging of Natural Gas and LPG meter installations

IGEM/UP/2 : Edition 3

Installation pipework on industrial and commercial premises

IGEM/UP/3: Edition 3

Gas fuelled spark ignition and dual-fuel engines

IGEM/UP/6: Edition 2

Application of compressors to Natural Gas fuel systems

IGEM/UP/9: Edition 2

Application of Natural Gas and fuel oil systems to gas turbines and supplementary and auxiliary fired burners.

IGEM/UP/10: Edition 4

Installation of flued gas appliances in industrial and commercial premises (Incorporating Amendments)

IGEM/UP/11: Edition 3

Gas installations for educational establishments IGEM/UP/16: Edition 1 Design for Natural Gas installations on industrial and commercial premises with respect to hazardous area classification and preparation of risk assessments (Incorporating Amendments) IGEM/UP/17: Edition 2 Shared chimney and flue systems for domestic gas appliances IGEM/UP/18: Edition 1 Gas installations for vehicle repair and body shops IGEM/UP/19: Edition 1 Design and application of interlock devices and associated systems used with gas appliance installations in commercial catering establishments (Incorporating Amendments)

IGEM/UP/20: Edition 1

Compressed Natural Gas fuelling stations

IGEM/UP/1101: Edition 1

Guidance on gas installations for the management and staff within educational establishments IGEM/IG/2: Edition 1 Guidance for gas engineers to the application of relevant sections of IGEM/UP/19 in catering establishments (Incorporating Amendments)

IGEM/G/6: Edition 1

Gas supplies to mobile dwellings

IGEM/G/11: Edition 1

Gas industry unsafe situations procedure (Incorporating Amendments)

IGEM/GL/8: Edition 3

Reporting and investigation of gas-related incidents

IGEM/GM/5: Edition 3

Electronic gas volume conversion systems IGEM/GM/6: Edition 2 Non domestic meter installations – Standard designs

IGEM/GM/7A: Edition 2

Electrical connections for gas metering equipment

IGEM/GM/7B: Edition 2

Hazardous area classification for gas metering equipment IGE/GM/8: Non domestic meter installations – Flow rate exceeding 6m3/h and inlet pressure not exceeding 38bar Part 1: Edition 2 Design

Part 2: Edition 2 Location, housing & compounds

Part 3: Edition 2 Fabrication, installation, testing and commissioning

Part 4: Edition 2 Operation and maintenance

Part 5: Edition 2 Notices and labels

IGEM/SR/25: Edition 2

Hazardous area classification of Natural Gas installations

Note 1: The HyDeploy Consortium consists of Cadent, Northern Gas Networks, Progressive Energy, Health and Safety Executive (HSE) Bespoke Research and Consultancy, Keele University and ITM Power.

Note 2: For the avoidance of doubt, this Technical Bulletin relates only to the operation of domestic installations with a blend of up to 20 vol% hydrogen in natural gas supplies, and does not constitute any guidance relating to 100 vol% hydrogen operations.

Bibliography

(1) HyDeploy project (https:// hydeploy.co.uk/) (2) Downstream Gas Standards Review, Blue Flame Associates (2020), available from IGEM upon request (3) Technical Bulletin 157, CO and combustion ratio checks using an Electronic Combustion Gas Analyser (ECGA) when carrying out works on natural gas appliances being supplied with natural gas containing up to 20 vol% hydrogen

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