These Oberdorfer™ centrifugal pumps have a single open vane rotating impeller. Liquid enters at the center and is thrown outward radically by centrifugal force. The impeller is not in contact with other pump parts resulting in quiet, efficient pumping action. The flow produced is not positive which permits the discharge line to be shut off completely without danger of overloading motors or bursting lines. Consequently, a relief valve is not required.
The flow of these pumps can be conveniently controlled by a throttling valve in the discharge line. Horsepower demand will decrease as the pressure increases. Maximum horsepower occurs with a wide open discharge.
The lip seal is Nitrile with stainless steel spring reinforcement on a stainless steel motor shaft. The seal is friction press fit in a machined housing counter bore. Excessive system pressures above 15 PSI are not recommended as the seal could be forced out of the pump housing.
One of the outstanding features of this pump and motor unit is its compact D.C. motor size. Although small, adequate motor power is available. Motors are available in 12, 24 and 32 VDC.
This pump is more than capable of pumping water, water solutions, and a wide range of commercial chemicals. Viscous liquids with a maximum viscosity of 2000 Saybolt Seconds Universal can be pumped. However, when pumping viscous liquids (as compared with water) a reduction in flow and pressure occurs and the required horsepower increases. Liquids heavier than water require additional horsepower in direct proportion to the increase in specific gravity. Questions about the chemical compatibility of special liquids should be referred to the factory.
These pumps are not self priming. They must be installed below the liquid level so that the liquid flows to the pump by gravity (flooded suction). However, if a foot valve is used at the beginning of the suction line, and all air is bled from the pump by manual priming, the pump will lift on the suction side up to 15 feet. Such a system relies entirely on the non-leaking foot valve for starting capability.