Designed for feeding small capacity steam boilers with water, for the use in water treatment plants, for handling water in hot water heating and water supply systems. Rigidly coupled, electrically driven vertical floor-mounted modular multistage segmental (ring-section) centrifugal pumps. Radial forces are taken up by internal medium-lubricated bottom plain bearing. Rotor axial thrust is absorbed by the motor bearing. Shaft sealing by a mechanical seal.