For high-pressure, room-temperature nitrogen using an orifice flow meter, what size should the pressure tapping be?

The diameter of the pressure tapping should not be too large nor too small, in order to ensure measurement accuracy and minimize the impact on fluid flow. Typically, the diameter of the pressure tap is determined based on the requirements of the measurement system and the pipe size. For DN50 pipes, a pressure tapping of φ23 is already relatively large. Moreover, the size of the pressure tap is generally less than or equal to 1/2 of the orifice diameter. The pressure tapping stub of φ22×4 that you provided – if it refers to an outer diameter of 22 mm and a wall thickness of 4 mm – is a suitable size for such a purpose. However, it is essential to ensure that there are no protrusions or burrs inside the tube, as these could interfere with fluid flow and pressure measurement. For flanges with ring joint surfaces, it is mainly related to the shape of the flange cover, and ring gaskets are used for sealing. It is feasible as long as the installation of the pressure tapping port and the pressure tapping short tube does not affect the sealing performance of the flange or the proper installation of the orifice plate. Overall, if all the above conditions are met and the system’s sealing and measurement accuracy are ensured, it is feasible to use a φ23 pressure tap along with the mentioned pressure tapping stub on a DN50 pipeline. However, it is recommended to consult the relevant flow meter manufacturers or professional engineers in detail before implementation, and refer to specific design standards and specifications to determine the most suitable size. .

Why is a orifice plate used instead of a vortex flow meter for DN50 process pipelines?