Counterflow prevention attaching indoor dead water plug null for cold area

摘要

PROBLEM TO BE SOLVED: To simplify and ensure the troublesome work of draining water using piping provided with a backflow-preventing indoor stop cock for use in clod districts and to prevent an operating failure due to freezing of remaining water. ;SOLUTION: A piece 33 which can be moved by a spring 36 is connected to the underside of a spindle 29 which opens or closes a passage 23 between an inlet 21 and an outlet 22. Circular packing 30 which always makes contact with a cylinder surface 31 is mounted on the underside of the threaded part of the spindle 29 which is engaged with the inside thread of an upper lid 28 secured to the upper side of a valve casing 20, and a release bar 37 which pushes up the piece 33 when preventing backflow is provided from the under to lower sides of the passage 23.;COPYRIGHT: (C)1997,JPO