Do You Know Why The Outlet Is Larger Than The Inlet Of The Centrifugal Pump?

Do you know why the outlet is larger than the inlet of the centrifugal pump?Today let us talk about theis question.Size of pump and pipeline inlet and outlet


The water inlet of the centrifugal pump is generally larger than the outlet, because the suction port is low pressure and the density of water is small and the flow rate is slow. In order to meet the requirements of water supply balance and ensure that there is a certain pressure head at the inlet to prevent cavitation, it is generally large; the flow rate of the outlet is fast and the flow rate of the same pipe diameter is large, so it is decided that the connected water inlet is larger than the outlet. The larger the diameter of the inlet, the smaller the suction resistance, the better for the suction medium of the pump, the smaller the diameter of the outlet, and the better for the pressure maintenance of the centrifugal pump outlet.

4X3C (1)

Whether the diameter of the inlet and outlet pipe of centrifugal pump is larger than that of the pump itself needs to be analyzed in detail. For most pumps, the purpose of increasing the diameter of the inlet and outlet pipe is to reduce the flow velocity of fluid in the pipe, reduce the resistance drop of the pipe, and ultimately reduce the power consumption of the pump, but increasing the diameter is at the cost of increasing the investment cost of the pipe, In this way, for the long-distance pipeline at the pump outlet, the pipe diameter can be appropriately increased to reduce the resistance drop, while for the short-distance pipeline, it is unnecessary to consider; for the materials transported at the centrifugal  pump inlet, such as liquefied gas, temperature close to boiling point, low suction position and other materials prone to cavitation, the diameter of the pump inlet pipeline should be increased to reduce the resistance drop and avoid pumping Cavitation


Generally, the diameter of the suction pipe is larger than the outlet pipe diameter, and the flow rate of the suction pipe varies according to the pipe diameter. When the pipe diameter is less than 250, it is 1-1.2m/s; when the pipe diameter is 250-1000, it is 1.2-1.6m/s. Technically, the maximum speed of water flow shall not exceed 2.5-3.0m/s, and the minimum speed shall not be less than 0.6m/s (to prevent sedimentation).

centrifugal pump (2)


If the centrifugal pump has been put into operation, how to judge the inlet and outlet of the pump?


According to the type of centrifugal pump, there are many kinds. The following are the ideas of the centrifugal pump housekeeper. Welcome to leave a message and add


1. The pipe diameter at the centrifugal pump outlet is generally smaller than that at the inlet;

2. When looking at the centrifugal  pump in the direction of the motor, the inlet is generally at the lower right part of the centrifugal pump head;

3. The general outlet has pressure gauge, one-way valve, guide valve, etc;

4. If not installed, the impeller of centrifugal pump can be seen from the flange port is the outlet.

5. If one of the inlet and outlet of the centrifugal pump is axial and the other is radial, then the axial is the inlet and the radial is the outlet.

6. If the inlet and outlet of the centrifugal  pump are radial, from the motor end to the direction of the centrifugal pump, the left side is the inlet, and the right side is the outlet.

7. Generally, the centrifugal pump manufacturer will mark the centrifugal  pump direction on the pump body, so the direction indicated by the arrow is the outlet, otherwise, the inlet.

centrifugal slurry pump