Issues with standard orifice plates for flange pressure tapping
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The anti-surge flow meter at the compressor inlet uses a flanged pressure tap orifice plate; during the initial installation, the pressure tap pipe was installed in a horizontal position, and because the pressure lead pipe was too long, condensation occurred on the negative pressure side during winter operations, resulting in the anti-surge valve flow reading dropping to zero. This causes the anti-surge valve to open fully, affecting stable operation! I would like to ask the experts on this forum: must the pressure tapping ports of such orifice plates be installed at 90° or 45°? How can this situation be remedied now? Can adding an isolation tank completely prevent this problem? Secondary dynamic welding of the compressor inlet pipeline is quite challenging!
In principle, the pressure tapping holes for gases can be installed 360°. However, considering the presence of condensation water, it is better to install it at an angle of over 45°, with vertical installation being ideal. Since it’s already installed horizontally, there’s no problem; simply adding electric heating will solve the issue.
GB 50093 has stipulations:
If a condensation tank is added, the pressure tapping pipe also needs to be disconnected and rewelded; it’s safer to first run the pipelines upward and then add the tank.
I'm sorry. I misremembered the specifications. It can also be installed this way if it is a gas medium that does not produce condensation.