Donkin Series 594 non-return valves are helping to ensure a consistent 25 mbar gas supply throughout the new Wembley Stadium.

Because of the large number of locations where gas is needed for cooking and heating, the designers of the distribution system decided to avoid possible pressure variations by boosting the supply up to 200 mbar as it enters the stadium and stepping it down again at each delivery point.

The two Donkin 10" (250mm) cast iron valves (one of which is shown here) 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. Series 594 valves were selected because of their versatility of application and ability to give a 100% gas-tight seal throughout low-and mid-pressure ranges.