| 摘要 |
<P>PROBLEM TO BE SOLVED: To reliably maintain a rust-proofing bush in an initial rust-proofing treatment state to reduce a restoring operation of rust-proofing treatment caused by the slip-out movement of the rust-proofing bush, and to renew an opening and closing valve efficiently, reliably and easily while achieving the reduction of the scale of a construction. <P>SOLUTION: A closure operation case is connected to a first opening and closing valve 3 joined to a branched pipe 2, a closure means A1 and a pushing means A2 in the closure operation case are sent to the branched pipe 2, a locking body 6 is pushed and fixed to a connection flange 2A of the branched pipe 2 with the pushing means A2 to close a flow path of the branched pipe 2 with the closure means A1. While leaving the closure means A1, a pushing means A2 and an operation shaft 16 as it is, the former first opening and closing valve 3 is removed from the connection flange 2A of the branched pipe 2. The closure operation case is connected to the connection flange 2A of the branched pipe 2 via a new first opening and closing valve 3 to draw the closure means A1 and the pushing means A2 into the closure operation case, and then the closure operation case is removed from the first opening and closing valve 3. <P>COPYRIGHT: (C)2012,JPO&INPIT |
