Principles for setting the outlet and inlet diameters of centrifugal pumps
Feb 06, 2023
Share:
Generally, the outlet diameter is selected according to the economic flow rate, and the outlet diameter is determined according to the flow rate. When the pipe diameter is less than 250, it is 1-1.2m/s, and when the pipe diameter is 250-1000, it is 1.2-1.6m/s. From a technical point of view, the speed of water flow It should not exceed 2.5-3.0m/s, and the minimum speed should not be less than 0.6m/s (to prevent deposition).
The inlet velocity is small, the advantage
1. It is beneficial to increase the NPSH of the device NPSHA, and the pump is not easy to cavitate;
2. The pipeline has little scour, especially the medium containing particles;
3. It is not easy to generate static electricity;
4. The pressure drop of the inlet filter is small;
5. In the same section, the medium flows evenly and the hydraulic loss is small.
The inlet velocity is small, the disadvantage
1. Under the same flow rate, the pipe diameter needs to be large and the pipeline cost is high;
2. For some easy-to-sediment media, the flow rate is too small, which may easily cause sedimentation and clogging;
3. The impeller inlet is large, the diameter of the mouth ring is large, and the leakage is large.
The inlet velocity is small, the advantage
1. It is beneficial to increase the NPSH of the device NPSHA, and the pump is not easy to cavitate;
2. The pipeline has little scour, especially the medium containing particles;
3. It is not easy to generate static electricity;
4. The pressure drop of the inlet filter is small;
5. In the same section, the medium flows evenly and the hydraulic loss is small.
The inlet velocity is small, the disadvantage
1. Under the same flow rate, the pipe diameter needs to be large and the pipeline cost is high;
2. For some easy-to-sediment media, the flow rate is too small, which may easily cause sedimentation and clogging;
3. The impeller inlet is large, the diameter of the mouth ring is large, and the leakage is large.
