High-pressure measurement from above
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Hello, experts! I believe experienced professionals have all encountered situations related to pressure measurement. I would like to ask: on a pipeline at a height of 4 meters, there are two pressure measuring instruments – one is an on-site pressure display instrument, and the other is a pressure transducer display instrument. Option 1 involves installing the instruments directly on the pipeline; the on-site pressure display instrument should be a model with a 250 mm dial, while the pressure transducer instrument is installed on the pipeline at that 4-meter height. An additional electronic display instrument is placed 1.5 meters lower down, connected to the transducer instrument above, so as to provide readings only at the lower level. This method is slightly more complex but provides accurate measurements. In Option 2, a DN15 pressure transfer tube is used to transfer the pressure from a height of 4 meters to one of 1.5 meters; display instruments and transmitters are then installed at the lower end of this pressure transfer tube. This approach requires a pressure transfer tube, and due to the height difference, an additional pressure of about 0.25 MPa is generated (4 m – 1.5 m = 2.5 m = 0.25 MPa). In Option 3, a capillary pressure transfer tube is used to transfer the pressure from 4 meters to 1.5 meters, with display instruments and transmitters installed at the lower end of the capillary tube. This method also requires a capillary tube, and again, an additional pressure of around 0.25 MPa is generated due to the height difference. I’m curious to know how experienced professionals handle such situations – please share your insights! ! Thank you! ! !
In industrial pressure measurement, it is indeed a challenge to accurately read the pressure in pipes at high elevations. Below is my brief analysis of the three options you proposed: Option 1: Install instruments directly on the pipeline. Advantages: – By being installed directly on the pipeline, it is possible to accurately display the pressure at that location. - It reduces the need for pressure Guide tubes or capillaries, thereby lowering the complexity of the system and potential leakage points. Disadvantages: - For remote reading of pressure transmitters, certain cable wiring is required, and an electronic display instrument must be installed at a lower location, which increases costs. Option 2: Use a DN15 pressure tapping pipe to lead the pressure to a lower location. Advantages: – The reading instruments can be installed on the ground or in a location where they are easier to view, making it simpler for operators and maintenance staff to read the readings. Disadvantages: - The static pressure difference caused by the pressure guiding tubes (i.e., head pressure) must be correctly calculated and compensated for; otherwise, it will affect the accuracy of measurements. - The pressure tap pipe needs to be filled with liquid, posing risks of freezing and leakage. Option 3: Use capillary pressure tubes to lead the fluid to a lower location. Advantages: – Compared to Option 2, capillaries are more flexible and easier to arrange, making them particularly suitable for environments with limited space or complex wiring. Disadvantages: - It is also necessary to compensate for the pressure difference caused by the height difference. - Capillaries are thin, prone to clogging, and their rupture can have a significant impact on personnel safety and system stability. When selecting a solution, the following factors need to be considered: – Requirements for measurement accuracy – Ease of maintenance and calibration – Installation and maintenance costs – Reliability and security of the system. Generally, if possible, Solution 1 provides the most accurate pressure readings, as it measures the actual pressure in the pipeline directly, reducing pressure variations caused by pressure transmitters. However, if it is necessary to read the pressure value at ground level or in a more convenient location, and the accuracy requirement is not very high (or static pressure compensation via the gauge is acceptable), then Option 2 or Option 3 can also be used. If Scheme 2 or Scheme 3 is used, it is important to ensure that the system can accurately compensate for the hydrostatic pressure difference in the pressure tap tube. Modern pressure transmitters usually have a compensation function, or this pressure compensation can be properly set through calibration during installation. Ultimately, you need to determine which option is more suitable based on the actual operating conditions and system requirements. In some cases, it may also be necessary to combine multiple techniques or employ special designs to achieve the best measurement results. If possible, consult professionals in field instrumentation and automation to obtain the most suitable solution for the specific application environment. .
The superimposed pressure of 2.5m should be 0.025MPa
Using pressure tapping pipes is nothing but theoretical; it lacks practical production experience. In the north, try this installation method and the errors it causes.
It is necessary to view the data displayed on-site; it can be led down using a capillary. If it’s not necessary, view it remotely on the DCS; if any abnormalities are detected in the display, then compare it with the values at the surface. Practicality.