What Are the Differences Between Centrifugal Pumps and Self-priming Pumps

In terms of working principle, the centrifugal pump relies on the centrifugal force generated by the high-speed rotation of the impeller to drive the slurry. This force pushes the slurry toward the edge of the impeller, causing it to be thrown out and flows along the pump's duct toward the outlet. Since the centrifugal pump requires liquid to fill the pump chamber before starting, otherwise the gas tether may occur, causing the pump to not work properly. In contrast, the self-priming pump not only has the function of generating centrifugal force when the impeller rotates similarly to the centrifugal pump, but also has the ability to self-priming. During initial startup, the self-priming pump can discharge air from the pump chamber through its special structural design, so that self-priming can be achieved without prior infusion of liquid.

In terms of starting methods, the centrifugal pump requires that the pump chamber must be filled with liquid in advance to avoid gas binding. If there is not enough liquid in the pump, even if the impeller rotates, sufficient suction force may not be generated to extract the slurry. The self-priming pump has a self-priming function and does not require manual infusion of liquid during startup. It can automatically discharge air from the inlet duct and suck into the slurry, enabling rapid start-up and continuous operation.

In suitable scenarios, centrifugal pumps are usually suitable for situations where the liquid source position is lower than the pump position and can ensure that the pump is filled with liquid during startup. For example, in water supply systems and industrial circulating water systems, the liquid source is usually at a low location, so a centrifugal pump is an ideal conveying device. The self-priming pump is suitable for situations where the liquid source position is higher than or equal to the pump position, or where the pump is filled with liquid during startup. For example, in applications such as mobile irrigation and temporary drainage, the self-priming performance of a self-priming pump makes it the first choice.

In addition, there are structural differences between centrifugal pumps and self-priming pumps. The self-priming pump has one more self-priming device than the centrifugal pump, such as the liquid storage chamber and return hole, which help to achieve self-priming and transport of liquids. In terms of self-priming performance, a self-priming pump usually has better self-priming height and self-priming time, which means it can establish sufficient suction force to operate in a shorter time.

Therefore, centrifugal pumps and self-priming pumps have their own characteristics and scope of application. When choosing a suitable pump type, factors such as the location of the liquid source, the starting method of the pump, and the required delivery performance need to be considered. By deeply understanding the working principles and structural characteristics of these two pumps, we can provide a reference for choosing appropriate liquid delivery solutions for different application scenarios.