| 摘要 |
A method and apparatus for manufacturing a bidirectional, corrosion and abrasion resistant gate valve body. In one embodiment, the gate valve body, including flange seals and a liner, are produced in a single molding operation. A mold with appropriate coring either forms or aligns any desired mounting inserts. Coring is also provided to properly form a packing area, gate passage, fluid passages, and flange mounting seals. Once the mounting inserts have been positioned in the mold cavity, the mold sections are secured together, and a filler material, preferably a thermoplastic resin, is injected into the cavity. Upon hardening of the filler material, the inserts are secured into position. Further, the entire body and liner are a single solid unit comprising the packing cavity, the gate slot for sealing flow areas, the flow passages, and the flange rings for sealing connection of the valve to other mating surfaces. In another embodiment, a valve liner is placed within the mold cavity before filler material is added. The valve liner, instead of the mold, defines the packing area, gate passage, fluid passages, and flange mounting seals.
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