External gear pumps use two sets of same gears with external teeth to create flow. The rotation of the gears is such that the liquid comes into the inlet port and flows into and around the outer of the two rotating gears. As the liquid comes around the periphery it is discharged to the outlet port. External gear pumps also have safety valve to protection the pipeline. Please feel free to contact me to get a detail free quote of our high quality wholesale price external gear pump! China Gear Pumps Manufacturer, Hoffwell pump will be your good partner!