The liquid flowing in the pipe may be mixed with air bubbles due to various reasons. For example, if the flow sensor is installed horizontally at the high or second high point of the piping system, it is easy to accumulate on the upper part of the horizontal pipeline and the flow sensor measuring tube, and the electromagnetic flowmeter will appear failure phenomena such as output shaking.
In order to facilitate the inspection of the cause of the fault and eliminate the accumulated gas, a manual exhaust valve should be installed near the downstream of the flow sensor at the high point or the next high point, and regular inspection and exhaust.
If the piping system has a high probability of occurrence of bubbles or is often mixed with bubbles, a gas collecting tank and an automatic exhaust valve should be installed upstream of the flow sensor. This technical measure is extremely important for medium and large electromagnetic flowmeters that measure raw water drawn from rivers. Such applications often contain air bubbles.