Pump Selection Is Not Difficult, Choose The Correct Standard Here

Dec 10, 2024

Select pump and list basic data:

1. Characteristics of the medium: medium name, specific gravity, viscosity, corrosiveness, toxicity, etc.

2. What is the particle diameter and content of solids contained in the medium.

3. Medium temperature: (℃)

4. The required flow rate for industrial pumps can generally ignore the leakage in the pipeline system during the process flow, but the impact of process changes on the flow rate must be considered. If agricultural pumps use open channels for water transportation, leakage and evaporation must also be considered.

5. Pressure: suction tank pressure, drainage tank pressure, pressure drop (head loss) in the pipeline system.

6. Pipeline system data (diameter, length, type and number of pipeline accessories, geometric elevation from suction tank to pressure tank, etc.).

When designing and arranging pipelines, the following points should be noted:

1. Reasonably choose the diameter of the pipeline. A larger diameter of the pipeline can result in lower liquid flow velocity and lower resistance loss at the same flow rate. However, due to its high price, a smaller diameter of the pipeline can lead to a sharp increase in resistance loss, resulting in an increase in the head and power of the selected pump, as well as higher costs and operating expenses. Therefore, a comprehensive consideration should be given from both technical and economic perspectives.

2. The discharge pipe and its pipe joints should consider the maximum pressure they can withstand.

3. The pipeline layout should be arranged as straight pipes as possible, minimizing the number of accessories in the pipeline and minimizing the length of the pipeline. When it is necessary to turn, the bending radius of the elbow should be 3-5 times the diameter of the pipeline, and the angle should be greater than 90 ℃ as much as possible.

4. Valves (ball valves or globe valves, etc.) and check valves must be installed on the discharge side of the pump. Valves are used to adjust the operating point of the pump, and check valves can prevent the pump from reversing and prevent the pump from being hit by water hammer when the liquid flows back. When the liquid flows back, a huge reverse pressure will be generated, causing damage to the pump

Selecting a pump to determine flow rate, head, and flow rate:

1. If the minimum, normal, and maximum flow rates have been given in the production process, the maximum flow rate should be considered.

2. If only normal flow rate is given in the production process, a certain margin should be considered. For high flow low head pumps with ns>100, a flow margin of 5% is taken. For low flow high head pumps with ns<50, a flow margin of 10% is taken. For pumps with 50 ≤ ns ≤ 100, a flow margin of 5% is also taken. For pumps with poor quality and harsh operating conditions, a flow margin of 10% should be taken.

3. If the basic data only provides weight flow rate, it should be converted to volume flow rate.