| 摘要 |
PROBLEM TO BE SOLVED: To provide jet type water feed device preventing backflow of water to a pump unit by using an automatic pressure regulating valve without using a water stop valve. SOLUTION: In the water feed device, the pump unit 2 has a suction passage connected with a well, a valve opening 11 connected with a discharge opening and the automatic pressure regulating valve 12 for opening and closing the valve opening 11. A jet part is provided in the middle of the suction passage and water in the pump unit 2 is fed under pressure to the jet part through a return pipe by rotation of an impeller. Water in the well is sucked into the pump part 2 through the suction passage under a jet action caused by the high pressure water spouting from the jet part due to the pressure feed. A diaphragm 13 of the automatic pressure regulating valve 12 is operated by water pressure caused in the pump unit 2 to open the valve opening 11, and water in the pump unit 2 is divided into the discharge opening. During operation shutdown such as maintenance of the feed water equipment, the valve opening 11 is hermetically closed by the diaphragm 13 of the automatic pressure regulating valve 12 and backflow of water from the discharge opening into the pump unit 2 is prevented. COPYRIGHT: (C)2007,JPO&INPIT
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