| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem wherein disassembling and re-assembling of a valve box constituting a tap body requires much time and labor because it was impossible to check back-flow preventive performance of a check valve in a back-flow preventive water cutoff valve without stopping water supply and the valve box has to be disassembled when exchanging the check valve and cleaning a strainer. SOLUTION: A bypass flow passage 4 communicating from a valve chamber of a main valve to a secondary side rear part of the check valve is set. A strainer installing element 3 capable of switching a water passage passing through the check valve and the bypass flow passage, and detachably installing a filter screen at a tip end on a primary side of the check valve is formed. Therefore, a unit which can be inserted in and pulled out from a water cutoff valve body is constituted. COPYRIGHT: (C)2009,JPO&INPIT
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