| 摘要 |
PURPOSE:To easily and safely dismount a gate valve at the time of repairing, etc., by injecting a liquefied gas into a hopper fitted with the gate valve to freeze the water stuck to the pebbles and to obtain a rigid frozen plug. CONSTITUTION:At the time of repairing the gate valve 2a, the flange connecting bolts between the hopper 1 and the main cut gate body 2 are detached while leaving the bolts on the four corners. A liquefied gas is then injected from the injection port 5 of the liquefied gas injection pipe 6 inserted into the hopper 1 on the main cut gate body 2 to freeze and bind the pebbles. The formation of the frozen plug of pebbles is confirmed by opening the gate valve 2a and making sure that the pebbles are not dropped. After confirmation, the connecting bolts on the four corners are detached from the main gate body 2, and the valve 2a is repaired or exchanged. |
