Set flow rate: usually refers to the predetermined flow rate value of fluid passing through a certain pipe or section based on system requirements. This value can be volume flow or mass flow, depending on the needs of the system or application.

For example, during the adjustment process of a manual control valve, the artificially determined "set flow" Kv is the flow coefficient of the manual control valve. This set value determines the fluid flow through the valve under certain conditions (such as the pressure difference remains unchanged). . When the system flow increases or decreases, the automatic regulating valve group will automatically adjust according to the difference between the actual flow and the set flow to keep the flow constant at the set value.