For instance, an engineer who deals with hydraulics would have to understand how to calculate the flow rate in liters per minute or Lpm of a hydraulic pump. These are the steps to follow when calculating Lpm of hydraulic pump:
Ascertain the displacement of the hydraulic pump in cubic centimeters (cc) or liters per revolution (L/rev). This information is usually contained in data sheet of the pump or manufacturer’s specifications.
Determine the speed of the hydraulic pump in revolutions per minute (RPM). This can be measured using a tachometer or obtained from the pump datasheet.
Use this formula to calculate either flow rate or Lpm:
Lpm = (Displacement x RPM) ÷ 1000
A typical example is as follows; suppose we have a hydraulic pump whose displacement is 50 cc/rev and it moves at 2000 RPM. Upon utilizing formula above, here is how we can find Lpm for that pump;
Lpm = (50 cc/rev x 2000 RPM) ÷ 1000
Lpm = 100 Lpm
Thus, the Flowrate or Lpm is equal to one hundred litres per minute. It should be noted that this calculation only estimates volumetric flow rates and does not account for any losses or inefficiencies within the system’s hydraulics.