The South Wales Gas Pipeline is the UK's largest high-pressure gas pipeline. The 197-mile (317 km) pipeline passing through Wales was built for National Grid plc and links South Hook and Dragon liquefied natural gas (LNG) terminals at Milford Haven, Pembrokeshire with the national gas network at Tirley, Gloucestershire.

South Hook LNG terminal is an LNG regasification terminal near Milford Haven and is the largest LNG terminal in Europe. Together with the smaller Dragon LNG terminal nearby, it can handle up to 25% of the UK's gas requirement. The first tanker docked on 20 March 2009.