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Butterfly Valve Figure 24

Keystone Butterfly Valves Figure 24 - 6278 A fully PTFE covered Butterfly valve acc. ISO 5752/5short (DIN 3202, part 3/K1). Actuator flange acc. ISO 5211. The range complies to both the high standards in various markets like chemical and petrochemical and to the latest standardisation parameters for Butterfly valves.

Features

•A one piece thin disc stem covered with 3 mmisostatically molded PTFE providing a veryminimum obstruction to flow.•The PTFE seat extends over the seat face tomake contact with the flanges to provide a reliable seat/flange sealing.•The seat and disc are the only two valve partsin contact with the medium.•Primary shaft sealing by preloaded contactbetween disc and seat hub.•Secondary shaft seal by oversizing the shaftdiameter in relation to the shaft hole in the seat.•Tertiary shaft seal (gastight) is accomplished byprecision machined, self adjusting chevron shaped PTFE seals.•Succesfull vacuumtests with helium have beenperformed with pressures less than 20 Pa (0,2 millibar).•Wafer type split body design.•The isostatically molded seat is speciallymachined to close tolerances to provide the following advantages: -low torque -less stress and deformation during opening and closing-eliminates tearing and bunching -is an integrated part of the primary, secondary and tertiary sealing in the shaft area.•Uninterrupted silicon rubber backing of thePTFE seat assures by its resiliency a positive contact and tight seating of the disc.•Integral body locating holes to ease installationand perfect centering of the valve between flanges. Silver plating For severe applications silver plated trim configuration available.

Technical data General application

Pressure (bar):10 Temperature (°C):-40 + 200Sizes (mm):50-300Flange acc.:PN 10/16ANSI 150Droptight shut-off in both directions up to10 bar, in accordance with DIN 3230 part 3, BN leakage rate 1. BO (gastight) is available on request. For services where common elastomers are unsuitable, Keystone offers animproved design Figure 24, oriented tochemical, pharmaceutical, cosmetic and food industries. The accurate machining of all valve components, and the combination of safety precautions in the shaft area provide a drop-tight seatsealing and a positive gastight shut-off through the shaft area to atmosphere.

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