When the vacuum pump unit is working, if it is found that the water pump has insufficient or no water, it should first consider whether there is air entering into the water inlet pipe due to sand holes, cracks or loose joints, and observe it to find out the air inlet. Some defects are very subtle, it is difficult to find them directly by naked eyes, which is often laborious and time-consuming without results. Then the editor will explain to you what we should do and how to deal with this situation

1、 Method of judging pipeline leakage

1. Duck feather method: use a piece of duck feather, and observe the flutter of duck feather when the water pump is running close to the suspected air inlet. In the same way, it can be operated with a lighted cigarette. Help with the direction of duck fluff and smoke.

2. Oil method: for difficult to find out the intake point, can be determined about the intake part of a little oil, oil quickly absorbed is the intake.

2、 Treatment measures for pipeline leakage

1. The installation position of the vacuum pump unit should be close to the water surface as far as possible to ensure that no air is sucked in when the water level drops.

2. When installing the suction pipe, the water inlet horizontal pipe should be slightly inclined downward or horizontally installed towards the incoming water direction. Any point of the water inlet pipe should not be higher than the water inlet of the water pump, otherwise the air in the pipe can not be exhausted.

3. It is necessary to prevent air leakage from the filling culvert. The tightness of the packing culvert shall be appropriate. If it is too loose, the packing gland shall be tightened; if the packing is damaged or invalid, it shall be replaced in time; if the water seal pipe covered by the packing is blocked and heated, it will cause air leakage in the packing cover, and the water seal pipe shall be cleaned.

4. Before the installation of the water inlet pipe connected with flange plate, the contact plane between the two flange plates shall be cleaned up, and a 3 ~ 5mm thick rubber pad shall be added in the middle, and the bolts shall be tightened symmetrically and in several times step by step.

5. The bottom valve of vacuum pump unit shall have enough submergence depth, and the submergence depth from the valve plane shall be 1.5 ~ 2 times of the bottom valve outer diameter, at least not less than 0.5 m. If the submergence is too shallow, it is easy to form vortices, so as to absorb air, produce cavitation and damage the impeller and pump shell. If it is found that the inlet water level drops rapidly when the pump is running, several boards can be placed on the water surface to reduce the vortex and prevent air from entering the pump shell.

6. The air pump unit body is equipped with a vent plug. In order to facilitate the deflation, a tap with the same thread size can be used to replace the vent plug, and the faucet can be opened when venting.

7. The vacuum degree at the suction port is limited. If the vacuum is too large, it is easy to vaporize the water in the pump, which is disadvantageous to the self-priming pump. Therefore, the pump has its maximum allowable suction, generally between 3 ~ 8.5m, should be controlled in this range when installed.

8. Pay attention to exhaust. Before start-up, sufficient water should be added to drain the air in the pump; at ordinary times, the vent plug on the pump cover should be opened regularly to eliminate the air accumulated in the pump.

When dealing with air leakage of vacuum pump unit, we can operate according to the methods and measures explained above, hoping to help you.