GB1096097A - Improvements in or relating to the construction of fluid flow control valves - Google Patents

Abstract

1,096,097. Making gate valves. GROVE VALVE & REGULATOR CO. wept. 5, 1966; Sept. 3, 1965; Sept. 14, 1965. No. 39622/66. Heading B3A. A fluid control valve body is made by welding a metal band 18 between and around a pair of metal plates 14, 16 to form an enclosure, securing a rigid member around the enclosure and introducing fluid into the enclosure to expand the plates outwardly with the rigid member restraining the expansion adjacent it so that the enclosure can be severed along the undeformed portion either before or after expansion to form an upper housing 10 and be secured to a rigid lower body 12 to form the valve body. A flange 26 is preferably welded to the upper body which is bolted 62 to a flange 60 welded to the lower body. A valve stem bearing 28 is secured to the band 18 to accommodate the valve stem 34. The lower body is preferably formed from relatively thick metal plates 46, 48 provided with tapped holes 58 for attachment to a pipe section. The valve closure disc 36 is formed from a circular plate 68 welded in a rigid ring 70 and is threaded on to the stem 34. In one embodiment the upper valve body is made by joining a pair of oval plates (82), Figs. 3-13 (not shown), by a metal band (84) and clamping the enclosure between a pair of rigid bars (90) which bisect the plates (82). Fluid under pressure is introduced at the opening (86) to expand the plates on each side of the clamp. The clamp is then removed and the enclosure severed along the undeformed portion to form two upper valve housings. A flange (26) is welded to each of the housings. In an alternative embodiment a pair of circular plates (96), Figs. 14-17 (not shown), are joined together by a channel member (95) which is welded around the periphery of each plate. The enclosure is clamped along a chord (D-D), expanded by fluid P and severed along the chord. A flange (97) is then welded to the housing. If desired the flange may be welded to the plates before the expansion. The channelshaped member 95 may be used with ovalshaped plates to form two housings. The valve closure discs 36 may be formed in various ways. In one embodiment a pair of sheet metal discs (104) are welded to a rigid ring (101) and fluid injected into the enclosure to expand the disc outwards, Fig. 18 (not shown). The ring (101) may be machined to provide annular recesses (112) for seat rings, Fig. 19 (not shown), or may be severed between the discs (104) to form a pair of single thickness closure discs, Fig. 20 (not shown). Instead of expanding the discs outward they may be forced inwardly in a pressure chamber, Figs. 21, 22 (not shown). The space between the disc may be filled with sand or other non-compressible substance.