DNV has been engaged to provide the evidence required to demonstrate the safe use and conversion of the local transmission systems (LTS) high pressure pipelines for transporting 100% hydrogen. The gas distribution company SGN manages around 3,100 kilometers of the LTS pipelines in the UK and is leading this project working in collaboration with the other UK gas networks. DNV will be providing key safety and operational evidence by carrying out a series of offline tests for this project at their remote research facility in Cumbria, Northern England. The programme of work will demonstrate hot working on hydrogen pipelines, delayed ignition and over pressure tests, burst and fatigue tests as well as exploring the hydrogen compatibility of existing pipeline connections and fittings. As the project progresses, DNV will also support a live network SGN trial by investigating the measurement and monitoring of a hydrogen linepack, the volume of gas that can be stored in a gas pipeline, on a section of the local transmission network. The LTS is owned and operated by gas distribution networks. These are the pipelines that connect the high-pressure National Transmission System with the lower pressure tiers. These pipelines are considered the ‘backbone’ of the energy network, currently delivering gas from NTS offtakes to towns and cities across the country.