| 摘要 |
903,922. Cleaning pipes; junction pieces. WILLIS, R. S. March 6, 1961, No. 8134/61. Classes 99(1) and 99(2). A " pig ball" recovery device comprises a valve housing 1 containing a valve chamber 2 and means connectable to flow lines 4, 4a leading in and out of the chamber 2, valve means 23 carried by a support 11, a valve seat 27, and " pig ball " recovery means comprising arresting means 40 for trapping the " pig ball" in the chamber 2, as shown, and " pig ball " receiver means 30 to receive the "pig ball" 41 upon being trapped, wherein the valve means 23 is movable to an unseated position permitting flow through the chamber 2 and permitting the passage of the " pig ball " from its trapped position in the chamber 2 into the receiver means 30 and the valve means is movable to a seated position permitting flow through the valve chamber and closing the receiver means 30 from the chamber 2. As shown, the valve head comprises a pair of annular members 23a, 23b held assembled on the end of a part screw-threaded stem 13 by means of split bushings 24, a retainer collar 25 and a retainer ring 26. The part 23a is formed with a seat for an annular resilient seating element 23c. The receiving means is formed by a housing 30 having a closure plug 31 in which is disposed a bleeder assembly comprising a plug 33 having a bleed screw 37 therein. The arresting means comprises a grid 40, having a series of longitudinal slots therethrough, which is seated in arcuate seats 41a and may be welded therein. A by-pass flow path P is formed around the grid so that when a " pig ball " 41 partially obstructs the openings in the grid 40, as shown, no significant reduction in flow area results. When the " pig ball " has been arrested in the valve chamber 2 the stem 13 is rotated to screw the latter through the bushing 14 disposed in a counter bore in the housing 11, force the " pig ball " 41 into the housing 30 and seat the valve element 23c on the seat 27 to seal the housing 30 from the valve chamber 2. Specification 903,923 is referred to. |
