For detecting full pipe of the medium at the pump inlet, is an ultrasonic fork better or a flow switch?
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This post was last edited by lurker on 2016-3-15 11:08. For detecting a full pipe of fluid at the pump inlet (with the aim of preventing gas from entering the pump, as this could damage it; the pump should be shut down immediately if gas is detected), is it better to use a fork-type sensor or a flow switch?
Neither of them will work, right? A tuning fork generates a signal whenever liquid flows past it. It’s not possible to detect a full tube. Just install a video monitor. No instruments needed; this also saves money.
In my opinion, a buffer tank can be added at the pump inlet, and an ultrasonic switch can be installed on that buffer tank to enable measurement
The electromagnetic flowmeter has an empty tube detection function built-in; it will give a warning whenever the tube is not filled.
If it’s not necessary to monitor flow rate and only need to check whether the pipe is full, then an SG (visual gauge) should be used; a visual gauge is designed specifically for this purpose
A pressure switch can be used to detect the liquid before the pump, as there is pressure of the fluid within the pipeline. But it’s not possible to measure when the pipe is full; the idea of using a sight glass as mentioned above for detecting fullness is also a good one. If it’s a vertical pipe, using a pressure switch would work as well……
Thank you. I didn’t explain it clearly enough. My goal is to prevent gas phase from entering the pump, as that could damage it; once gas phase is detected, the pump should be stopped immediately via interlock
I think installing a gas collection tank with a float switch inside would work fine
A tuning fork and a flow switch will generate a signal as long as there is flow; they are unable to detect when the pipe is full. You can try installing an eccentric reducer at the pump’s inlet and a concentric reducing fitting at the outlet to prevent cavitation.