| 摘要 |
<p>969,440. Valves. H. E. McGOWEN. Feb. 22, 1963 [June 11, 1962], No. 7209/63. Heading F2V. In a rotatable plug valve, fluid pressure inlet and outlets are connected through an orifice plate contained within the plug and removable to interchange the size of orifice. Valve plug 11, within chamber 13 between inlet 15 and outlet 16, is rotatable upon cap 25, interlocked thereto by a dependant key 28 within a recess of the plug stem 21, between open and closed positions against a stop 24 and is locked in either position by a spring plunger 30. Orifice plate 1, having dependent handle portion 3 and carrying detachable orifice disc 5 secured by sealing ring 6, is retained within a slot of the spherical valve plug 11 by cover plate 18 which is removable to permit the plate 1 to be withdrawn through an axially directed slot 17 within the wall 14 of the valve body, when the valve is in the closed position, by engagement of a tool within holes 9. Inlet 15 and outlet 16 are fitted with interchangeable coupling members 32 and 38 each of which serve to retain annular P.T.F.E. seals 35 and 41, within retainer rings 36, forming bearing contact with the plug 11. The inlet pressure may be measured via a tubular boss 43, opening into the chamber 13, communicating with inlet 15 through passageway 44 when the plug is in the open position and the outlet pressure measured via tubular boss 42, annular space 45 and plug passage 48. Prior to removal of the orifice plate 1, with the plug valve 11 in the closed position, the valve chamber 13 is relieved of pressure via needle valve 49 seating upon a P.T.F.E. bushing. After replacing the orifice plate 1 the valve chamber 13 is pressurized to protect the seals 35 and 41, via passages 54, 55 and 57, needle valve 68, ball check valve 61 and passage 62 to the chamber 13.</p> |
