| 摘要 |
<p>1,017,316. Valves. A. C. F. INDUSTRIES Inc. Jan. 31, 1964 [Feb. 4, 1963], No. 4319/64. Heading F2V. A rotatable spherical plug valve comprises a body A having a chamber 10, a spherical valve member B positioned in the chamber and having a port 20 extending therethrough, two end members C secured one to each end of the body and having frusto-conical inner ends 14, each with a seat groove 16, and a seat member D located in each groove, each seat member in its free condition comprising an annular ring having a frusto-conical face portion 46 opposing the spherical valve member, the relation between the other walls of the seat member and its groove being such that upon assembly of the valve the frusto-conical face 46 wil rotate outwardly away from the axis of the valve bore causing the inner wall 36 of the seat member to lose contact with the corresponding wall of the groove and the outer wall 38 of the member to approach the corresponding wall without making contact, a conical portion 44 at the back of the seat member also approaching the bottom of the groove without making full contact. A slot 22 for engagement by the valve spindle E is disposed at right angles to the valve bore so that the valve member may be displaced by fluid-pressure against the downstream seat which then makes full contact with the groove along its faces 38 and 44. The seat members may be of P.T.F.E., nylon, polychlorotrifluoroethylene or hard rubber and may incorporate a dry lubricant or a filler such as asbestos or glass fibre.</p> |
