Selection Principles of Pumps

1. Make the type and performance of the selected pump meet the requirements of process parameters such as flow rate, head, pressure, temperature, cavitation flow rate and suction distance of the device.

2. Medium properties must be satisfied.

For pumps transporting flammable, explosive, toxic or precious media, reliable shaft seals or acceptance of leak-free pumps, such as magnetic drive pumps, barrier pumps, shielding pumps, and convective components are required to accept corrosion-resistant materials, such as AFB stainless steel corrosion-resistant pumps, CQF engineering plastic magnetic drive pumps.

For pumps transporting solid granular media, the convective parts are required to accept wear-resistant materials. When necessary, the shaft seals are flushed with clean liquid.

3. Machine has high reliability, low noise and low vibration.

4. Economically, we should consider the lowest total cost of equipment deployment, operation, maintenance and handling.

5. Centrifugal pumps are characterized by high speed, small volume, light weight, high obedience, large flow rate, simple layout, no pulsation in infusion, stable performance, easy operation and convenient maintenance.

Therefore, in addition to the following environment, centrifugal pumps should be selected as far as possible:

1. When there is a measurement requirement, the metering pump should be selected.

2. Reciprocating pumps can be used when the head requirement is high, the flow rate is small and the high head centrifugal pump can not meet the requirements of small flow. If the cavitation requirement is not high, scroll pumps can also be used. When the head is very low and the flow rate is large, axial flow pumps and mixed flow pumps can be used.

3. When the medium viscosity is high (greater than 650-1000mm2/s), it is considered to choose rotor pump or reciprocating pump (gear pump, screw pump) 4. When the medium content is 75%, the flow rate is small and the viscosity is less than 37.4 mm2/s, the scroll pump can be chosen.

5. Pumps with self-priming performance, such as self-priming centrifugal pumps, self-priming scroll pumps and pneumatic (electric) barrier pumps, should be selected for places where starting frequency is still low or irrigation pumps are inconvenient.