Do Pumps Suck?
I will begin this blog by posing a question: Does suction really exist? Take a moment, decide upon your answer and let’s go on this journey together.
A majority of people in the pumping industry would say yes, suction has to exist. If you were to ask any ten year old child with a bottle of cola and a straw he will state “Of course it does! How could I drink from my straw if it didn’t?” If the child was asked to elaborate, he would explain how he uses his mouth and the straw to pull the liquid into his mouth. However, the physics of how he gets his drink to his mouth is slightly different. If you can understand this difference then you will understand why pumps don’t actually pull liquid in which will help you to understand all of the resulting limitations that exist.
To delve further into this subject let me provide you with an example. The photo below illustrates a simple horizontal end suction pump set-up to “suck” water up and out of the pond. The basic forces in play here are centrifugal force and atmospheric pressure.