| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive piping facility capable of preventing the occurrence of breakage and water leakage even if a high specific speed mixed flow pump is started in an abnormal condition with all of opening and closing valves in a piping system closed. SOLUTION: The opening and closing valves 17 to 19 are attached to a pipe 11 connected with a discharge port 14a of the high specific speed mixed flow pump 14, and bypass pipes 20 to 22 bypassing these opening and closing valves individually are connected with the pipe 11. Bypass valves 23 to 25 are individually attached to each bypass pipe, and corresponding opening and closing valves and bypass valves are individually connected through transmission mechanisms 26 to 28 constituted by combining a plurality of gears. The bypass valves are closed in the interlocking relationship with opening of the opening and closing valves and are mechanically opened in the interlocking relationship with closing of the opening and closing valves. Consequently, even when all of the opening and closing valves 17 to 19 are closed, the high specific speed mixed flow pump 14 does not perform shutoff start and performs minute opening start substantially.
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