| 摘要 |
1,065,209. Valves. GRAY TOOL CO. March 2, 1966 [May 24, 1965], No. 9055/66. Heading F2V. A parallel plate-type gate valve has two opposed gate plates 56 co-operating with seats 32. The plates are slidably mounted on pins (192), Fig. 6 (not shown), inserted in a carrier (172) and are moved outwardly against the seats in closed position. A gate expander 160 comprises two legs 166 depending at the lateral sides of the gate from a sleeve 162. This sleeve has a flange 164 whereby it is allowed limited vertical movement between abutments. The free ends of each leg 166 widen in wedge surfaces 206. Two rollers 196 can move outwardly in grooves in the carrier. The ends of these rollers engage the wedge surfaces 206 to force the plates apart in closed position. The rollers are located axially by a pin (194), Fig. 6. On retracting the gate, the expander can move upwardly until it engages a sleeve 98, 100 whereby it is released from the gate. The sleeve 98, 100 has opposite conical surfaces engaging corresponding surfaces of slightly different angle on the valve body 10 and on a cover which is secured hard against the body by screws 88 so as to deform the sleeve 98, 100 and effect sealing. Flowable plastic lubricant is supplied to the seats through passages 48 which open externally of the body and are plugged at 50. Similar lubricant is supplied to a space 127 between gland packing 124. In another embodiment, Figs. 7 and 8 (not shown) the valve is of rising stem type. The loose gate plates 56 are omitted. Two opposed plates carried directly by the valve spindle have wedge surfaces (292) engaging the surfaces (206). In a modification, the valve is of non-rising stem type, and a nut adaptor (302) accommodates the gate plates to the screwed stem. An anti-corrosion sleeve (326), Fig. 10 (not shown), may be fitted in the flow passage. This has a flared end (332) co-operating with an elastic hard metal sealing ring secured between flanges of the valve and an adjacent pipe by a wedge clamp (338). |
