GB1050982A - - Google Patents

Abstract

1,050,982. Pneumatic conveyers. F. E. SWAIN. Dec. 6, 1963 [Sept. 11, 1962], No. 34630/62. Heading B8A. [Also in Division F2] A valve for controlling the flow of powders includes a valve closure member 21 of circular cross-section and a seating ring 18 housed in an annular recess 16 in the wall of the valve housing 10, the seating ring having a smaller axial thickness than the recess so that it is axially movable as a result of fluid pressure on one side of the closure member and the seating ring until the opposite face of the latter meets the adjacent radial face of the recess. A further sealing ring 41 of resilientlycompressible material, and of a substantially circular section when unstressed has a diameter greater than the depth of the groove in which it is housed plus the axial clearance between the seating ring and the recess 16. A retaining ring 14 is a push-fit in the housing or, alternatively, it may be threaded. The seating ring 18 is spaced from the periphery of the recess to permit radial expansion, and may contain a metal reinforcing ring. As shown, the member 21 is a butterfly valve member. The clearance between the seating ring 18 and the recess accommodates the clearance of the shaft of the butterfly in its bearings, and axial valve member deflections under load. Fluid pressure on the left of the valve member in Fig. 2 causes the sealing member to be moved against wall 15. Fluid pressure on the other side causes opposite movement, and the passage of the fluid is prevented by ring 41. A further annular sealing member may be inserted between the periphery of the recess and the seating member 18.