Diameter change in pump inlet and outlet pipes? ! Is preventing cavitation the most important reason?
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rt!! thanks!!!
Preventing cavitation is not the most important reason
What’s the reason for that? ! It has the effect of preventing cavitation, right? Thank you. . . . .
The main reason is to ensure a proper feed pipe in order to prevent issues such as cavitation and blade stall, so it’s reasonable
Are there any other factors that can increase energy conversion efficiency?
The inlet necking is intended to reduce cavitation, while the outlet expansion is designed to convert kinetic energy into static pressure energy
The change in diameter of the pump’s inlet and outlet pipes is primarily intended to reduce pressure losses and meet the requirements of typical process installations; based on the specified parameters, the diameters of the inlet and outlet are determined during the design phase
The diameter changes of the pump’s inlet and outlet pipes are determined based on the pressure drop; the inlet must be designed to prevent cavitation, which requires minimizing the resistance loss, hence a larger pipe diameter is used； It’s fine if the pressure drop is a bit higher when a guaranteed discharge head is required; therefore, reducing the diameter can help save on costs. However, there are specifications outlined in the manuals regarding the pressure drop per 100 meters in the outlet pipeline, so the diameter cannot be reduced by too much.
The inlet flow velocity of the pump is generally higher than that in the pipeline. If the diameter does not change, this results in high resistance losses in the suction pipeline, and the pump is also prone to cavitation
A larger diameter at the inlet is mainly used to improve the net positive suction head of the device, while a smaller diameter at the outlet can reduce the flow velocity of the fluid in the pipeline and increase its pressure energy.
If the pipe diameter is reduced, the flow velocity increases and the static pressure decreases.