| 摘要 |
PROBLEM TO BE SOLVED: To surely prevent the generation of back flow from a storage tank even if working abnormality or service interruption is generated. SOLUTION: Hot water pouring solenoids 62, 66 are installed in a hot water pouring passage 50 branched from a hot water circuit 2 and pouring hot water in a bath tub, and a negative pressure break valve 64 having a direct acting valve 642 which is a normal open electromagnetic driving type is arranged between the hot water pouring solenoids. When power is supplied, a communicating port 646 on the atmosphere side opening in a valve chamber 643 is closed, when power supply is stopped, the communicating port 646 is opened with a spring 644. In order to change from a hot water supply state where a negative pressure break valve is closed and both hot water pouring solenoids are opened to a stationary state, after the hot water pouring solenoids are closed, when a pressure relief valve 67 is instantaneously opened, inner pressure remained in a valve chamber 643 is released, and the direct acting valve being pressed by inner pressure is opened with the spring. Even if closing work abnormality is produced in the hot water pouring valve, when the hot water pouring circuit becomes negative pressure, air is immediately sucked from the communicating port and negative pressure is dissolved. When service interruption is generated, driving current is supplied from a capacitor to the pressure releasing valve, and the direct acting valve is opened by releasing the inner pressure. COPYRIGHT: (C)2003,JPO
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