GB959913A - Butterfly-type fluid flow control valve - Google Patents

Abstract

959,913. Valves. B. H. HADLEY Inc. July 10, 1962 [July 25, 1961], No. 26433/62. Heading F2V. A butterfly valve 20, Fig. 3, disposed between flanged pipes 13, 14 is provided with an annular seal 21 on either side of the movable closure member 22; the sealing member consists of a radial inwards part 33, Fig. 4, for contacting the curved edge 35 of the member 22, a horizontal support part 37, a radial outwards part 38 and a horizontal rib 39 engaging an annular groove 40 in the valve casing 26. The sealing member is retained by an L-section annular element 42 and loaded by a spring 47 whilst the element 42 is secured by a ring 50 and a number of set screws 53 which may be adjusted to give uniform contact of the part 33 with the member 22. The sealing means is responsive to a decrease in temperature for tighter engagement with the closure member. The closure member 22 is formed by a pair of spaced walls 60 interconnected by a central web 61 with a through-port connecting the two openings 68 by which fluid flows when the valve is open; the surfaces of the openings are faired to prevent turbulence. The edge 35 is a sector of a sphere having a radius equal to that of the main flow passage on either side of the closure member; the edge may incorporate a circumferential groove 75. A similar groove 75 may also be provided on the opposite face of the closure member to permit of reversal of the latter. The closure member is splined to stub shafts 62, 63, Fig. 3, having an axis which is parallel to but laterally displaced from that of the closure member 22 so that in the valve-openposition the seal part 33 is spaced from the member 22. Each stub shaft is housed in sealing, bearing and axial thrust means 77, the lower shaft 62 terminating in a housing 94 from which a fluidpressure indication of the valve position is obtained. The upper stub shaft 63 has an extension 100 that passes through a slot 116 Fig. 2, in an actuator plate 115, the extension being connected to an arm 119 with a roller 118 that is received in an opening 117 along one wall of the slot 116 and is spaced from an arcuate face 122. Each end of the plate 115 carries a piston 124 comprised of an outer wall 126, Fig. 6, and an inner wall 127 with a common piston ring 128. Upon admitting pressure-fluid by a pipe 159, Fig. 2, to act on, say, the left-hand piston 124, the plate 115 travels to the right, the roller 118 follows the plate 115 and turns the extension 100 to operate the closure member. As the right-hand piston 124 approaches a stop 157 it forces fluid out of the pipe 161, but some of this fluid enters the space between the walls 126, 127 and acts to damp movement of plate 115 when the outer wall 126 finally abuts the stop 157; at the same time the spring action of the piston ring 128 on the associated cylinder walls provides a further frictional damping effect. In a modification (Fig. 9, not shown), the closure member comprises a single plate with lugs for engagement by the stub shafts and the annular seal is of V- or L-section with the inner leg inclined to the plane of the closure member. In a further modification, a chamber 221, Fig. 10, between the stub shaft 63<SP>1</SP> and housing 220 receives escaping controlled fluid which then vaporizes and aids in sealing the stub shaft. The latter is splined to a cam 119<SP>1</SP> with top and bottom plates 225 supporting a roller 118<SP>1</SP>. The stub shaft may actuate a switch means and the actuator 105 may be used to develop a sealing pressure in chamber 221.