The principle of peristaltic pump is that the runner squeeges the pump tube and rotates to push the fluid in the tube to move forward to produce fluid flow, just like squeezing a hose full of liquid with two fingers. With the movement of the finger, negative pressure is formed in the tube, and the liquid flows with it. Therefore, the peristaltic pump is a positive displacement pump. The liquid in the pump tube is driven out by the runner of the pump head. After the runner leaves, the pump tube will steadily rebound and inhale new liquid. Our peristaltic pump head will produce a constant flow rate per revolution, and the flow rate will increase by the same revolution per revolution per unit time. Therefore, the flow generated by the peristaltic pump in the specified speed is constant. Because the peristaltic pump has this characteristic, the user often calls the peristaltic pump a constant flow pump.
Peristaltic pump belongs to a kind of constant flow pump, because there are many kinds of pumps can realize the function of constant flow, such as diaphragm pump, plunger pump, screw pump, etc., so peristaltic pump is only a kind of constant flow pump.