f H21 Hydrogen Compatibility of Components Phase 2: Final Report

Concerns relating to the production of carbon dioxide (CO₂) and its effects on global background temperatures have led to international efforts to reduce CO₂ emissions. A contributor to CO₂ emissions is the burning of natural gas in domestic and commercial fuel supplies. The use of hydrogen is being explored as a potential alternative to natural gas.
As part of the work associated with delivering H21’s 100% hydrogen gas network, a requirement to develop a method of assessing the suitability of gas distribution network assets (e.g., pipes, valves, regulators) for use with hydrogen up to 7 barg was identified. Phase one of the project developed such a methodology, which was delivered to the project stakeholders to conduct component level analysis of assets and determine their suitability without further mitigation. The methodology developed in phase 1 of this project under NIA 276 was used to assess a wide range of assets, a number of which were considered as being not suitable for use with hydrogen, according to the methodology, without further mitigation.
The asset assemblies which did not pass the assessment method at the first stage were district governors/regulators, service governors, underground modules and slam shut valves. The materials that were identified as having high degradation level scores, contributing to the overall ‘fail’ result, included various carbon steels, spring steels, cast aluminium, certain brasses, one polymer and a range of brand-name sealants.
The work described in this report is a re-assessment and update of the various inputs that make up the method, a detailed analysis of function and loading of selected failing assets, and an evaluation of where new materials testing may permit an update of the materials degradation ratings. Fifty-seven assets failed the initial assessment, of which twenty-seven were identified for further evaluation in this project.
This report was submitted to HSE for their assessment of the safety evidence for 100% hydrogen heating, which can be found at Hydrogen heating: HSE assessment of the safety evidence - GOV.UK.
Queries should be directed to DESNZ: https://www.gov.uk/guidance/contact-desnz.