Orifice flow meter
Thread Content
I designed an orifice plate flowmeter myself. I would like to ask an expert for help. I want to measure the pressure difference between the front and back of the pipe. How should I determine the measurement position?
It depends on which pressure-taking method you use. Different pressure-taking methods have different pressure-taking point locations. The specific pressure taking methods include flange pressure taking, corner pressure taking, and distance pressure taking.
Orifice plate flow metering pressure measurement is generally used for flange pressure measurement if it is less than or equal to 12" (DN300), 90-degree angle connection, gas is led from the side, liquid is led from the bottom of the side, and diameter distance is used for pressure measurement if it is greater than 14", 1D in front and 0.5D in back (D is the diameter of the pipe)
What are the values less than 12 and greater than 14? Can I find it in that book?
Flange pressure taking: The position of the differential pressure sensing tube is 24.5 ± 0.5 from the upstream end face of the orifice plate. Of course, the tolerance is small and good.
Orifice plates generally use front and rear flanges to draw pressure pipes to measure the pressure difference.
The standard orifice plates currently used generally use the blue pressure removal method, and the center of the upstream and downstream pressure holes is 25.4mm away from the corresponding orifice plate surface.
There must be a certain length of straight pipe section before and after the flowmeter, so as to ensure that the measured pressure is accurate. For orifice flowmeters, generally 14D in the front and 7D in the back, D is the nominal diameter of the pipe... You can take the pressure at these two positions, or 10D in the front and 5D in the back. The pressure measurement method has been mentioned by experts before. If the medium is gas, a longer straight pipe section is required.