What happens when an electromagnetic flowmeter is used with a pipe that is not full?
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As the title suggests, there wasn’t really a suitable location for installation, so it was placed at the highest point of the horizontal pipe, which results in incomplete filling of the pipe. The deviation is quite large now; what should be done?
Change to vertical installation. If nothing else works, add a valve behind the flow meter
If it cannot be installed on a vertical pipe, can the section of pipe containing the flow meter be modified to an inclined pipe that is lower at the front and higher at the back, with the bottom of the higher end being above the top of the flow meter?
You said the deviation is large; then we have to find a way to get it to fill the tube completely
An electromagnetic flowmeter is designed based on the entire cross-sectional area of the pipeline 【Volumetric flow rate (Q) = Average flow velocity (v) × Pipeline cross-sectional area (A)】； When the pipe is not full, one must find a way to fill it with the medium ； There are electromagnetic flowmeters that can measure the medium level in a pipe that is not completely filled; the principle behind them is the use of a device similar to an electric contact level gauge to detect the degree of filling in the pipe. Since it is not possible to continuously detect the level of the full tank, the error remains relatively large.
If it’s not satisfied with the flow rate, find a way to make it satisfied by adjusting the pipeline
There’s no other choice; we have to find a way to fill it up
Add a bend at a distance of about 10D behind the flow meter
The last edit to this post was made by In the rain_KDTE on 2017-11-15 at 14:39. Reduction in diameter is allowed provided that the process conditions permit it (not more than 50%), the flow rate of the medium should not exceed 3 m/s, and the pipe must be filled completely. Pay attention to the straight sections before and after; generally, 5D in front and 2D behind are required.