| 摘要 |
PURPOSE:To definitely identify whether pressure change has been caused by the change in climatic conditions or gas leakage by connecting a volume variable type cushion tank which absorbs the pressure drop occurring in the change in climatic conditions to a piping or vessel. CONSTITUTION:In a piping 3 provided with an on-off valve 1 on primary side and usually plural on-off valves 2... on secondary side, a volume variable type cushion tank 4 is connected to a suitable place between the primary side on-off valve 1 and the secondary side on-off valve 2 on the uppermost stream side or to a place near the primary side on-off valve 1, and a limit switch or contactless switch SW1 which detects more than fixed displacement of the displacement member 4a built in the tank 4 by the contact or proximity with or to this displacement member 4a is mounted in the predetermined position of the tank 4 as a device 5 for detecting the drop of pressure in the piping 3 to a fixed value, and this switch SW1 is connected to an alarm device 6. |
