Below is a list of Self Priming Pumps manufacturers from Middlesex, New Jersey. Self-priming pumps are centrifugal pumps that retain a small volume of fluid in order to start up without requiring outside attention to clear their passages of air. Centrifugal pumps convert mechanical energy into kinetic energy by increasing the pressure of a liquid but can become air bound, a circumstance in which the pump is too full of air to operate correctly.