You notice that the variables in the Known Flow Rate equation are piston radius, piston stroke length, backflow rate, and motor speed. You observe that the in-house machine shop controls the piston radius and stroke length while the backflow valve and motor are purchased components.
the machine shop indicates it is capable of 3-sigma quality levels within a tolerance of ±1 millimeter (mm) for the piston radius and stroke length. the purchasing department asks you to use an inexpensive backflow valve and motor.