f MOBs Phase 3: Task 9 - Fire Protection Measures

There is a requirement for gas distribution network (GDN) operators to understand the cost, safety, and practicality of converting network pipelines from Natural Gas (NG) to Hydrogen in multi-occupancy buildings (MOBs). SGN is leading a feasibility project with some applied testing to understand the steps needed to convert to Hydrogen.
This report is for work pack 3, Task 9: Fire Protection Measures. The objective of this task is to review the applicability of current requirements for fittings and components relating to the permissible leakage rate during, and after, a high temperature event where Hydrogen is the gas being distributed.
The objectives of this task are to:
• Confirm the applicability of the test temperature of 650°C (currently specified in BS EN 1775 Procedure B and which corresponds to the self-ignition temperature of a Natural Gas / air mixture) with Hydrogen self-ignition temperature.
• Confirm the applicability of the specified leakage rate of 150 dm3/h for pipework components during and after a test in accordance with the requirements of BS EN 1775 Procedure A.
• Confirm the applicability of the specified leakage rate of 150 dm3/h for pipework components following a resistance to high temperature test in accordance with the requirements of BS EN 1775 Procedure B.
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.