minimum flow line

By examining the performance curve of the pump, the minimum flow line is determined based on the minimum flow point.

Usually, only centrifugal pumps are equipped with a minimum flow line, which is intended to prevent the pump from overheating and being damaged under low-flow conditions. Other types of pumps, such as positive displacement pumps, do not require a minimum flow line. .

This post was last edited by shashaloveyou99 on 2024-9-6 at 11:27. Many pumps have this setting! 1. Pumps that are operated frequently – since the drive system has a limited number of start-ups it can withstand; for example, motors have a certain limit on the number of starts. With a return line, when the pump is not in use, the outlet can be closed to allow automatic backflow, eliminating the need to shut down the pump ； 2. Pumps with extremely low flow rates: In some applications, a very low flow rate is required. However, for pumps whose flow rate is already fixed, the lower the flow rate, the worse the pump’s performance becomes, and cavitation may even occur. Therefore, a return line is installed to increase the pump’s flow rate ； 3. Some large pumps are difficult to start; for example, some high-temperature pumps require preheating before starting, and some high-head, high-power pumps take a long time to start and have complex operation procedures, so it is possible to keep the pump running continuously ； 4. Protection for large pumps: Large pumps take a long time to start up and shut down. To prevent the medium inside the pump chamber from vaporizing during these processes (especially in areas with narrow gaps and little medium, such as the wear-resistant rings, balance drums, sleeves, and static and dynamic seal rings), which could lead to dry grinding, a low-flow line is installed in such cases.

Positive displacement pumps are not called minimum flow lines; they are called return lines, which are used to adjust pressure or flow.