To measure the pressure, it requires a measurement system. In order to accurately measure, except for the correct selection and calibration of the pressure gauge, it is necessary to pay attention to the correct installation of the whole system. If only the shock pressure gauge itself is accurate, its number does not fully represent the actual parameters of the measured medium, because the error of the measurement system is not equal to the error of the pressure gauge.
The correct installation of the system includes the opening position of the outlet, the reasonable laying of the connecting catheter and the correct installation position of the pressure gauge.
1. Select the position of the pressure outlet
(1) Avoid the area in which the pipeline bends, forks and the flow bundles form vortexes.
(2) when there is a prominent object in the pipe (such as the temperature measuring element), the outlet should be taken in front of it.
(3) When the pressure is required to be pressed near the regulating valve, if the pressure outlet is in the front of the valve ,the distance from the valve shall not be less than 2 times the diameter of the valve before it is pressed. If the pressure outlet is followed, the distance from the valve should be no less than 3 diameters.
(4) For the broad container, the pressure outlet should be in a stable and non-eddy current region. In conclusion, the location of the selected pressure port on the process flow should be able to ensure that the parameters are selected.
2. The laying of the catheter
The horizontal section of the catheter should have a certain slope
to exclude condensation liquid or gas.
When the measured medium is gas, the catheter should lean in the direction of the outlet. When the measured medium is liquid, the pipe should be inclined towards the direction of the measuring instrument. When the measured parameters are small differential pressure values, the inclination can be slightly larger. In addition, if the catheter is in the turning corner,you must place the condensate device at the lowest point or install the exhaust device at the top according to the medium in the catheter to ensure that not due to accumulated in the duct condensate liquid or gas affect measurement accuracy. Condensate or gas should be discharged regularly.
