Why is the diameter reduced at the installation locations of steam pipeline flow transmitters, pressure transmitters, and thermal resistors?
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Why is the diameter reduced at the installation locations of steam pipeline flow transmitters, pressure transmitters, and thermal resistors? For example, in the section where the measurement points are arranged, the diameter changes from DN200 to DN100 over a length of about 6 meters.
Since the flow meter is designed for a specific diameter and requires straight sections before and after it, there are straight sections of pipe with the same diameter as the flow meter on either side of it. If the diameter of the flow meter is smaller than that of the process pipeline, then these straight sections must be replaced with pipes that have the same diameter as the flow meter. This has nothing to do with thermometers or pressure.
Does that mean that when a vortex flow meter is installed, the flow velocity has to increase, becoming twice its original value?
When selecting a flow meter, the flow velocity factor needs to be taken into account; if the flow velocity in the process pipeline is suitable for a flow meter with a constant diameter, then there is no need for a diameter change； However, most pipelines are designed with a margin, meaning the flow rate is relatively low; therefore, when calculating with a flow meter, it is necessary to adjust the setting by one or even two levels until both the pipe diameter and flow rate are appropriate. It should also be noted that bid-driven price reductions are one of the reasons for choosing a lower caliber for flow meters.
It has something to do with the interface flange of the flow meter, I guess. . . It has nothing to do with the pressure and temperature of the main pipeline, right?
Flowmeters and similar devices are very expensive; reducing their size by one scale level can save a significant amount of money. The optimal design size is usually determined using the calculation software provided by the manufacturers