Water flow control method for low flow rates
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I would like to ask everyone for advice: my unit is currently designing an experimental apparatus with a flow rate of 2L to 5L/min, and we need to achieve very precise temperature control. The key factor here is the amount of water used for cooling. There are no centrifugal pumps available with low flow rates on the market. Plunger pumps are positive-displacement pumps that operate in one direction only; since plunger pumps discharge water in only one direction, it seems that a control valve cannot be used with them, right? Can a gear pump be used?
Why can’t a control valve adjust the flow rate? Also, can the metering pump meet the requirements?
It can be adjusted by using a needle-type control valve.
Use a regular centrifugal pump with a control valve, allowing adjustment to whatever level is desired.
The flow rate of a positive displacement pump cannot be adjusted; using a needle valve doesn’t work either
In that case. Add a return bypass between the pump and the needle valve, upstream of the pump. Reduces the instability in the pressure before the valve caused by the fixed flow rate of each volumetric pump. Actually, needle valves can be made. It’s just a change in the pressure before the valve.