Donkin Series 594 non-return valves from Aqua-Gas AVK are helping to ensure correct gas pressures at the new Wembley Stadium in the UK. In order to accommodate the requirement for a standard 25mbar supply at the large number of locations where gas is needed for cooking and heating, it was decided to boost the pressure up to 200mbar to maintain comprehensive distribution around the stadium. The two Donkin 250mm cast iron valves are on the worker and standby outlets of the underground booster station, where they prevent the boosted supply feeding back and over-pressurising the low- pressure supply from the main. The valve bodies are constructed from cast iron (594) or ductile iron (595) in sizes from 150mm to 750mm, and in fabricated steel in sizes of up to 1200mm, with carbon steel doors and stainless steel door spindles. All valves are CE-marked and comply with the requirements of the Pressure Equipment Directive.