Does excessive diameter variation in pipes have a significant impact on production?
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There are many diameter changes in the pipes at my factory; the inlet and outlet pipes of the pumps in my workshop also have such diameter changes. It is said that this was because the design and equipment selection were finalized beforehand, only to find that the sizes of the pipes did not match those of the pump outlets, so numerous diameter changes had to be made. What do you think? Will so many diameter changes have an impact on production? Will it also affect the pumps?
Of course it has an impact; every change in diameter results in a pressure drop, and energy consumption increases.
The answer isn’t entirely comprehensive. My suggestion is to focus on your production capacity first, calculate the material balance, and based on the flow rates of the liquid and gas phases, determine the diameter required for each type of material. This way you can see how much the change in diameter affects your production. I’m not sure if the answer is thorough enough
There are reasons why varying diameters are chosen in pipeline design. 1. The diameter changes at the pump inlet and outlet are mostly due to the differences between the flow rate criteria set by the pump manufacturer and those of the pipelines; generally, the diameter is reduced at the pump inlet and increased at the pump outlet. 2. Generally, the control valves installed on pipelines also need to have their diameters reduced, in order to enable these valves to achieve a good control curve. 3. In vertical sections of pipes for two-phase flow, a reduction in diameter is generally required to enable mixing of the gas and liquid phases, thereby preventing plug flow from occurring. Therefore, the diameter change needs to be analyzed according to different parts.
I agree with your view. However, once the process piping layout has been determined, the pipe diameters and any required reducers are essentially fixed. If the issue of pipe diameter is ignored during equipment selection, it’s very likely that the diameter of the equipment pipes will not match that of the process pipes. By then, the equipment has already been purchased and delivered, and the project timeline is tight; in such cases, the simplest and most common solution is to use reducers to compensate for this mismatch. Under normal circumstances, this does not have a significant impact on production. Changes in the pipe diameter cause changes in the flow velocity of the fluid within the pipe (as well as pressure changes): when the pipe diameter decreases, the flow velocity increases and the pressure rises; when the pipe diameter increases, the flow velocity decreases and the pressure falls. Because when designing, a certain margin is taken into account when selecting pumps, so it generally has little impact on the pumping operation.
It will certainly increase the frictional resistance of the fluid, and the installation and connection of the pipes are also troublesome; it may also lead to leaks
There is definitely an impact; energy consumption increases. Whether it can be used or not depends on the margin left when selecting the pump, the value of the increased resistance, and the production load of your facility.