What is the reason for the sudden decrease of the flow of self-priming pump and the solution

The reason why the flow of self-priming pump becomes smaller and the solution.

Before the self-priming pump in normal use, the flow is normal, but suddenly the self-priming pump obviously feels that the flow is getting smaller and the outlet pressure is getting lower. I don't know what the reason is. Many users want to search for the reason of the flow becoming smaller on the Internet to find out. It's necessary for us to share the reasons for the flow becoming smaller and the solutions for the flow becoming smaller for reference:

1. If the self-priming pump with high suction head is used, because the inlet pipe of the self-priming pump is not tightly sealed, there is slight air leakage, because there is a vacuum auxiliary system or the self-priming pump has strong suction force, and the self-priming pump has slight air leakage under the condition of low suction height, the self-priming pump can also pump up water, but because there is a little air suction phenomenon, the air may cause the flow of the self-priming pump to suddenly change Small reason, this self-priming pump flow smaller solution is to check the leak point repair.
2. As the leakage of mechanical seal of self-priming pump is also the cause of the flow of self-priming pump becoming smaller, replace the new mechanical seal.
3. There are sundries in the pumped medium, which may be caused by the blockage in the impeller flow passage, or some users have installed a bottom valve or filter screen at the bottom of the suction pipe of the self-priming pump, which may easily lead to the blockage of the filter screen and bottom valve. If there are too many sundries, it is suggested to choose our open impeller self-priming pump or self-priming pump with cutting.

4. Another possibility is that the self-priming pump has been used for a long time, and the impeller in the pump cavity is corroded or worn, resulting in a smaller impeller size, which can only be replaced by a new impeller.
5. The reason why the flow of the self-priming pump with the cutting function becomes smaller may be that there are large pieces of sundries in the pipeline that are blocked between the impeller of the self-priming pump and the ring at the inlet of the self-priming pump. At this time, as long as the cleaning plate with the cutting self-priming pump is disassembled, you can see whether there are objects that cannot enter the pump body to clean it up.
6. There is another reason why the flow of the self-priming pump becomes smaller: if the impeller of the self-priming pump with cast iron body is made of stainless steel impeller, because of the metal foreign matters in the pump body, the metal objects are stuck between the impeller and the pump body, this situation suddenly occurs during the rotation of the self-priming pump, because of the thin position in the pump body, this situation is very tolerant It is easy to cause breakdown of individual positions. After breakdown, the water inlet and outlet of the self-priming pump are directly the same, which will also cause the flow of the self-priming pump to suddenly decrease. So other reasons that do not dismantle the pump are eliminated, and then the pump can only be disassembled for physical examination and repair.

7. Other users found that the flow of the self-priming pump became smaller after the self-priming pump was disassembled and installed and put into operation. This may be caused by the fact that the impeller of the self-priming pump was not installed in place. For example, a flat pad was added behind the impeller of some self-priming pump products. After the maintenance, the customer forgot to install the flat pad, which will cause the impeller to The direction of the motor moves backward, and the impeller is not in the specified position, which is also the reason why the flow of the self-priming pump becomes smaller. In this case, only the impeller of the pump is removed again and the gasket is installed again.