Why do magnetic flap level gauges need to be equipped with drain valves and vent valves?

　　The structure of the magnetic flap level gauge is simple, mainly composed of a float, a magnetic float, a flap, a display panel, a display panel end cover, a connecting flange, a drain valve, a vent valve (not basic, sometimes a hexagonal plug or even a flat welding cap can be used, depending on user needs and specific working conditions), etc. In the structure of the magnetic flap level gauge, many people are curious about why the magnetic flap level gauge needs to be equipped with a drain valve under the instrument, and some even have a vent valve installed above the instrument?

This is because after the magnetic flap level
　　gauge has been running for a period of time, a lot of dirt will easily accumulate at the lower end of the magnetic flap level gauge float, and the inner wall of the float will also be sticky with dirt, which will inevitably affect the normal measurement of the magnetic flap level gauge. In addition, when the magnetic flap level gauge fails and needs to be repaired, it is quite necessary to remove the liquid and dirt in the float.

　　At this time, you can first close the upper and lower stop valves connected to the measuring tank to stop the magnetic flap level gauge from working, and then open the drain valve at the lower end of the magnetic flap level gauge to drain the liquid or dirt in the float, so as to smoothly carry out maintenance and drainage work and enable the measurement work to proceed normally.

　　But sometimes, due to the stubborn dirt inside the float, it still cannot be removed even after the above operation. At this time, it is necessary to use the vent valve installed on the upper end of the magnetic flap level gauge to assist in draining. Specifically, a water pipe is connected to the vent valve on the upper end of the magnetic flap level gauge, and clean water or steam is passed to flush or purge the float. Generally, the inside of the float can be flushed clean and the instrument can resume normal operation.

　　In addition, if the inner wall of the float is dirty, the float is close to the inner wall of the float with no gap, and the air is held at the upper end of the float, the dirt in the float cannot be discharged from the lower end by the drain valve alone. At this time, the dirt in the float can be discharged smoothly from the drain valve at the lower end by using the vent valve at the upper end.