Stainless Steel End Suction Pumps are one of the most common types of centrifugal pumps. They are almost always single stage pumps, and one of the most cost effective types of centrifugal pumps. End Suction pumps usually have one impeller and volute type casing. They work when the pump liquid increases velocity as it moves along the vanes of the impeller, then the liquid move in the volute casing where a diffuser converts high velocity to high pressure.