Improvements in valves for fluids

摘要

994,540. Valves. WHITEY RESEARCH TOOL CO. Sept. 11, 1963 [March 25, 1963], No. 35771/63. Heading F2V. In a rotary spherical valve the closure 18, upon integral stem 19, is enclosed by and operates within a cylindrical polytetrafluoroethylene cage comprising upper and lower halves 10 and 11 which are restrained under compression, within a central chamber 6, by the adjustment of a packing nut 32 bearing upon a packing gland 29 having grooves 31 which engage the upper half 10 of the cage. Cold flow of the polytetrafluoroethylene under compression is minimized by steel bushes 21, thinly coated on both faces with polytetrafluoroethylene 22, which surround the passageways 4 and 5 and are spaced from the body of the valve and from the closure 18 to permit flow of resin into the spaces 23 therebetween; and by steel discs 27 in diametrically opposed apertures 26 of the polytetrafluoroethylene which align with and prevent flow into the bore 20 in the closed position. The ball 18 is rotated by a handle 34 secured by a set screw 35 upon stem 19 and rotation is restricted to 90 degrees, between the open and closed position, by the abutment of a 90 degrees arcuate lug 37, upon the handle 34, against a raised portion 38 of the bonnet 7 which extends over 180 degrees. Upon release of the set screw 35, the handle 34 may be rotated to align longitudinal holes 39 therethrough with holes 40 in the nut 32 and, with a tool inserted through both sets of holes, the handle 34 is used to rotate nut 32.