Submersible pumps are designed with the impeller house to be immersed into the liquid. Because of this a mechanical seal will not be needed. Above the fact that this pump has no bearings or other friction surfaces inside the pump house.
A submersible pump is limited in self-priming, where the pumps has to start below liquid level. The quality of this submersible pump is achieved by the aulity of molding process by which the pump parts are fabricated.
The applicability of these submersible pumps are very wide due to the high quality and the proper quality-price condition.