Mechanical Equipment Topic 03: Problems caused by a small diameter in the centrifugal pump’s outlet pipe
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This post was last edited by zx9527007 on 2009-12-8 at 19:55. The DAP uses a washing pump of the type 525LC125/405; its flow rate is 360 m3/hr, and the outlet pipe has a diameter of DN80. Is this too small? What problems might arise from a flow velocity of 20 m/sec?
The flow rate is 360 m3/hr, and the outlet pipe has a diameter of DN80, which is too small; for such a high flow rate, pipes with a diameter of DN250 or larger should be used for water.
An outlet pipe with DN80 will do; it’s not small, and this is the most economical option.
Agree with what was said on the 2nd floor. The outlet diameter is too small, which affects the outlet flow rate; I’m afraid the flow rate you require cannot be achieved.
Calculate the pipeline network curve carefully; the flow rate should not reach that level. You should provide the characteristic curve of the pump
It’s not just a matter of it seeming too small; the selection of a pump needs to be based on the requirements of the process. Pumps are generally chosen according to these process requirements, with all parameters meeting those specifications!
The flow velocity at the pump outlet is too high; the main problem is that the pipeline resistance is very high, which results in high energy consumption when transporting the fluid. In severe cases, this affects the flow rate and prevents it from meeting the required levels； Typically, the appropriate range for liquid flow velocity is 1–3 m/s; in such cases, the pipe diameter should be between DN175 and DN300 mm. The flow velocity mentioned by the poster is 20 m/s, which is too high – such a velocity is comparable to that of gases.
Empirical data: Using water as the medium. Nominal pipe diameter (mm): 50, 80, 100, 150, 200, 250. Flow rate (cubic meters per hour): 10, 30, 50, 100, 250, 400. Of course. The pipe diameter can be adjusted appropriately according to actual conditions. For reference only.
A washing pump needs to generate high-pressure, high-flow fluid to carry out the washing function. The diameter of the pump’s outlet pipe is usually determined during the design phase of the pump; in practice, the diameter of the outlet pipe can be adjusted slightly, typically by 1–2 sizes larger than the original diameter, as otherwise it will significantly affect the pump’s performance.
It’s too small; this will increase losses and noise.
The outlet is too small, so the pressure drop will be significant.