| 摘要 |
A pig launcher (10, 38) comprises a cassette (12, 41) adapted to receive at least one pig (14, 16, 18, 20) and a latch mechanism (28a, 28b, 28c, 28d, 42a, 42b, 42c) comprising a latch member (30, 46). The latch member is movable from a first protruded position wherein the latch member restricts movement of the pig relative to the cassette in a launch direction to a second retracted position wherein the latch member does not restrict movement of the pig in the launch direction. The pig launcher also comprises a flow control valve (30, 32, 35, 36, 44a, 44b, 44c, 48) which is adapted to pass fluid into the cassette when in an open state and to restrict flow of fluid into the cassette when in a closed state. The arrangement is such that the latch mechanism and the flow control valve are operatively associated with each other so that when the latch member moves from the first protruded position to the second retracted position the flow control valve simultaneously moves from the open state to the closed state.
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