Powergen has chosen Keystone Figure 56 butterfly valves from Tyco Valves & Controls for critical water services at its Connah’s Quay power station. A key factor in securing the order was Tyco’s ability to select specific valve materials to withstand the highly corrosive and abrasive properties of the application. Connah’s Quay, a gas-fired power station, was commissioned in 1996 and produces 1420mw of electricity, exported to the national grid for general consumption nation-wide. The valves will form an integral part of the plant’s cooling water system. Special consideration had to be made in the choice of the valves because of the power station’s position on the Dee Estuary. Seawater extracted from the estuary is not only highly corrosive, but also contains silt from the riverbed which is abrasive. In order to minimise the effect of seawater and silt, careful consideration had to made in the selection of valves materials to be used. To ensure protection of the valve body, and smooth operation of the application, the valves have been supplied with a butyl rubber lined, epoxy coated cast iron body, an EPDM seat bonded to an aluminium bronze carrier, and a nickel aluminium bronze disc with stainless-steel shaft. Keystone’s Figure 56 butterfly valve is particularly suited to water applications within power generation plants, offering the advantages of self-lubricating sleeve bearings, which allow for horizontal or vertical installation of the valve shaft, non-metallic bearing material and flexible flange design to enable flanges to be chosen according to specific applications.
