Positive displacement valves are precision dispensing devices designed to provide precise fluid dispensation depending on applications. They function by opening quickly, releasing product and closing again. This process may take place numerous times per second. They use physical moving force to drive material out of the valve and are used to dispense materials with high viscosities. They use one of two mechanical means to distribute their product, either by auger or a rod or piston. Auger pumps are driven by a feed screw as the feed screw turns, it forces the media out of the valve. Rod or piston pumps use a moving shaft to drive media towards its destination.