METHOD FOR INSTALLING VALVE ON EXISTING PIPE AND VALVE USED FOR THE SAME

摘要

PROBLEM TO BE SOLVED: To improve efficiency and save labor in removal work after valve installation and to surely and easily execute the work even under a condition that length of cut removal pipe part of the existing pipe is shorter than pipe diameter. SOLUTION: A valve box A of a divided structure is installed on the existing pipe 1. An open close valve B for work capable of being freely opened and closed is attached on a valve element insertion opening 8 side of the valve box A. A section to be cut and removed of the existing pipe 1 is cut and removed with cut width smaller than pipe diameter D thereof under a continuous flow condition by a cutting device E installed on the pipe part to be cut and removed in the valve box A. After a cutting device E is taken out to outside through a valve element insertion opening 8 of the valve box A together with a pipe part 1A cut and removed, the valve element 2 provided with a cover part 2A sealing the valve element insertion opening 8 of the valve box A is inserted and fixed under a condition that the same does not touch a cut end surface of a cut remain pipe part to close a flow passage of the existing pipe 1 by pressing the valve element 2 against a valve seat 20 formed on an inner wall surface of the valve box A. COPYRIGHT: (C)2005,JPO&NCIPI