What is a rotary pump?  Essentially a circulating pump will continuously transfer hot water in the loop while it is running. It simply takes water and discharges it at high pressure to the required points, and returns it to the line system for proper circulation. A pump has inlet and outlet openings. Both of these are in the same line with each other.  

What are the types of submersible pumps?  Types of submersible pumps is Deep well pump  Bottom suction pump  Stainless steel pump  Oil filled pump  Submersible utility pumps  Water cooler pump  Mixed and axial flow pumps

What is a submersible pump? Basically it is a type of centrifugal pump. Instead of pulling water like normal cases, a submersible pump pushes water. It consists of a hermetically sealed motor attached to the pump body which helps in pushing the liquid to the surface. The impeller plates used in this pump are of backward curved type, which helps in pushing the water with great force. Its motor converts rotary motion into kinetic energy, and diffuser blades convert this kinetic energy into pressure energy.