f SNG Safety Management Framework: Managament Procedure for Converting Natural Gas Installations in Multi-occupancy Buildings to Hydrogen

This procedure details the process of how riser and lateral installations currently supplying Natural Gas to domestic accommodation within multi-occupancy buildings (MOBs) are selected and converted to Hydrogen or identified for decommissioning and the provision of an alternative option.
This procedure describes the requirements for conversion of existing Natural Gas installations in multi-occupancy buildings to Hydrogen operating at pressures not exceeding 75 mbar. For gas installations deemed unsuitable for conversion it provides guidance for decommissioning and alternative energy solutions. The gas supplied is assumed to be 100% Hydrogen as specified by IGEM/H/1, and therefore does not cover blends of Hydrogen and Natural Gas.
This procedure covers guidance for:
• The identification, selection and commissioning of network risers and laterals, installed in existing multi-storey buildings, deemed suitable for repurposing to Hydrogen as they currently are.
• The requirements to identify buildings that are not suitable for repurposing in their current form and outlines the necessary replacement or partial replacement, renovation, alteration or repair of existing riser and lateral installations from the pipeline isolation valve (PIV) through to the supplier’s emergency control valve (ECV) to enable Hydrogen conversion.
Note: Where an existing Natural Gas installation is to be repurposed for Hydrogen, it will have been subjected to a pre-conversion survey and risk assessment to ensure components are suitable for use or otherwise replaced.
• The identification, isolation and decommissioning of network risers and laterals, installed in existing multi-storey buildings, not deemed suitable for conversion to Hydrogen.
• The provision of alternative arrangements in the form of an energy centre or an alternative option such as heat electrification, heat pump or heat network.
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.