Is this a fake self-priming sewage pump?

If the flow quantity of your self-priming sewage pump becomes smaller and smaller, will you doubt if it is a fake one?

Self-priming sewage pump is different from common centrifugal sewage pump, since the latter has to be filled with water before it starts. That is to say, self-priming pump doesn’t have to be filled with water before it starts. It can draw water up by itself after running for some time and then begins to work normally.

Self-priming sewage pump has many categories. Each category has many models of distinctive features, application fields and functions.

Self-priming sewage pump has two categories based on its function.

1. Air-liquid mixture type
According to the position where the discharged gas and the circulating start-up liquid blends together, air-liquid mixture pumps have two kinds of structures, internal mixture structure and external mixture structure.

2.Non-clogging self-priming sewage pump can deliver wastewater, the models of which usually have digit and letter.

According to the working environment, self-priming pump has three subcategories as follows:

3.Domestic self-priming pump
This subcategory mainly includes domestic self-priming pump for hot or cold water and self-priming sewage pump with small flow quantity and high head.

4.Industrial self-priming sewage pumps include clear water ones and direct connection ones. The former has a coupling, taking more floor space while the latter has its impellers installed on motor shaft, taking smaller floor space.

5.Self-priming sewage pump
This pump can deliver wastewater containing all kinds of impurities.

6.Why does the flow quantity of the pump become smaller and smaller?

1. Clogging is the most common cause. When the inlet or outlet of this pump gets clogged, its flow quantity will surely decrease. What you should do now is to open the pump and remove the clogging materials.
2. Mechanical seal leakage is a simple cause that is easy to find.  In this case, you just need to change for a new one.
3. The third possible reason is gas leakage. If not all the air in the inlet pipe of the pump is discharged, it will possibly cause cavitation, which will have great influence on the flow quantity.
4. The last reason is one-way valve.