| 摘要 |
PURPOSE:To make it possible to perform calibration with the devices being attached to a plant, by connecting a pressure relief value and a diaphragm type displacement device for calibration to a pressure pipe after an initial valve, and connecting a diaphragm to the side of the pressure to be measured of the displacement device, whose inner pressure can be changed. CONSTITUTION:An initial valve 2 is provided in a pressure pipe 9 from a process pipe 1. A pressure relief valve 12 having a closing plug 4 is provided in the pipe 9 on the measuring side of the valve 2. A diaphragm type displacement device 11 for calibration is connected to the pipe 9 through a flange 5 having a diaphragm. The measuring side of the device 11 is connected to a capillary tube 7 of a gage 8 through a gage diaphragm 6. A non-compression type pressure medium is sealed in the displacement device 11. A calibrating pipe 10 having a test valve 3 with a closing plug 4 is connected to the displacement device 11. At the time of calibration, the valve 2 is closed and the valve 12 is once opened and then closed again. The plug 4 is removed and a opened and the pressure in the pipe 10 is changed by the pressurizing device. Then the gage 8 is calibrated. |
