| 摘要 |
A caisson gate valve (10) fitting within an outer casing (12) extending downwardly from a subsea wellhead below the sea floor is disclosed. The gate valve (10) includes a valve body or block (14) having an axial bore or flow passage (16) therethrough and a transverse cavity (18) in body (14) which extends through the body (14) to provide open ends (19) for cavity (18). Covers (60, 66) are mounted over the open ends (19) of cavity (18). A gate carrier (24) has an oval opening (26) which receives a gate member (28) having a gate opening (30) therein for movement between open and closed positions relative to the flow passage (16). A pair of opposed stems or pistons (32, 34) extend from gate carrier (28) for actuation of gate carrier (24) and valve member (28) between open and closed positions relative to flow passage (16). Fluid chambers (36, 38) adjacent pistons (32, 34) provide pressurized fluid for actuation of gate carrier (24) and gate member (28) therein.
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