| 摘要 |
<p>955,509. Valves. M. W. KELLOGG CO. March 8, 1961 [May 16, 1960], No. 8439/61. Heading F2V. A valve comprises a body 12, Fig. 1, having a fluid passageway therethrough, a valve seat 91, Fig. 5, in the body disposed across the passageway, a valve gate having a main frame 47 and an adjustable member 63 defining a face disposed at an angle approximating to that of the seat, the adjustable member being mounted in the gate so as initially to contact the seat prior to being fully seated and then to remain in rubbing contact with the seat until fully seated, resilient means 68 disposed between the main frame and outer portions of the adjustable member being pre-loaded independently of the latter. The resilient means 68 may comprise a circular series of helical springs or stacks of conical disc springs assembled between annular plates 72, 73, Fig. 16, adjusted by bolts 74 to provide the preloading. The valve 10 is welded to conduits 11, has an insulating lining 40 and is actuated by an hydraulic cylinder 19 to which the stem 22 is coupled by a clevis 21. A valved drain line 26 permits removal of seepage material. Water is supplied to the closure assembly 29 through tube 38 inside the hollow stem 22 and exits therefrom through the annular space between the tube and stem, the water being supplied through connections 39a, 39b separated by a baffle 39c. The adjustable member in the form of a valve disc 63 is mounted on each of a pair of flanges 59 and has a flat portion plated with chromium to engage the valve seat. Lugs 67 engage lugs 61 on the flange 59 after the adjustably preloaded springs 68 have been put into position to leave the discs capable of limited universal movement. A baffle member 71 bolted to the back of each disc forms an annular waterway and the space at the back of the discs is cooled by lateral outlets 82a and branches 83 in a tube 82 telescoped over the tube 38. Each valve seat 91 has a water jacket formed between members 80 and 93 and provided with inlet and outlet tubes 94, 95. Cooling water is also supplied to longitudinal passageways in guideways 97, Fig. 13, for the closure assembly 29. During operation of the valve the stem 22 which passes through a stuffiing box 28 flexes sufficiently to accommodate movement of the closure assembly due to the difference in fluid pressure. The packing 32 for the stuffing box may include a central lantern ring or spacer and the lower end of the box has a conical seat 30, Fig. 13, to engage a seat 31 on the stem 22 when the valve is fully open. The valve may be fabricated from either carbon steel or a low ferritic alloy such as carbon-¢% molybdenum steel. The Specification refers to operating temperatures and pressures.</p> |
