| 摘要 |
An adjustable butterfly valve of known type is improved by the addition of a plastic, e.g., Teflon, liner disposed between the valve disc and elastomeric seat to isolate corrosive fluids in the valve from the seat. The valve comprises a pair of spaced, axially aligned pipe ends having a resilient seat therebetween, and associated with a pair of radially spaced body members bearing on the outer diameter of the seat and having inclined interior surfaces in engagement with complementarily inclined exterior surfaces of the pipe ends to permit radial and axial compressive forces exerted on the seat to be simultaneously adjusted by adjustment of the body members toward and away from one another. An annular plastic liner separate from the seat is disposed around the flow passage through the valve between the inner diameter of the seat and the periphery of the valve disc, and the pipe ends are provided with annular grooves which receive the axially spaced edges of the annular liner. Each pipe end is further provided with an annular flange extending in an axial direction generally parallel to the inner diameter of the liner, with each flange terminating in a sealing lip extending radially toward and into sealing engagement with the inner diameter of the liner. A central portion of the liner protrudes in a radial direction between the lips into sealing engagement with the periphery of the valve disc and with shoulders provided between the disc and its supporting shaft.
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