| 摘要 |
<p>PROBLEM TO BE SOLVED: To efficiently and easily perform the removal work of a valve lid having a valve body and a valve rod in a non-interrupted flow state.SOLUTION: In a valve lid removal method of a gate valve V1 which removes a valve lid 4 from a valve box 2 in a state that flows of fluids in both pipe parts 1 are maintained, the value lid 4 is pressed and fixed to the valve box 2 in a sealed state via an upper part of a valve lid cover 10 by using first pressing means C1 composed of a frame-shaped member which is attached and fixed over both regions with the valve box 2 sandwiched therebetween out of external peripheral faces of both the pipe parts 1, and connection between a connecting bolt 8A for connecting a flange 4A of the valve lid 4 and a flange 2D of the valve box 2 and a connecting nut 8B is released. An attachment 30 is fixed to an upper face of a divided ring 35 which is supported and fixed from a lower side with respect to the flange 2D of the valve box 2, the valve lid 4 is pressed and fixed to the valve box 2 in a sealed state via an upper part of the valve lid cover 10 by using second pressing means C2 which is arranged at the attachment 30, the first pressing means C1 is released from both the pipe parts 1, and the press fixation of the upper part of the valve lid cover 10 performed by the first pressing means C1 is released.</p> |
