ADVANTAGES

• High efficiency: Means “lower operating costs” over the life of the pump, this is because of the lower power requirements, and the efficiency of the impeller to suit the application.

• Variable Head: The Axial-Flow pump has the advantage of delivering a near constant rate of flow with varying lift, such as occurs in river. Also, the efficiency is high over a wide range of heads.

• Submerged Turbine: The word “Turbine” is commonly used to describe the Axial-Flow impeller and bowl or stator assembly, which may be single or multi stage. The in-line shaft drive is convenient for a system in which the turbine is submerged under all water level conditions. The practice of locating the turbine underwater is common with all Axial-Flow pumps. The system of having the turbine submerged results in many benefits, especially simplification, and avoidance of complications in equipment an operation.

• Self-priming: With no priming necessary Axial-Flow pumps are easy to start up.

• Suction lift is avoided: In other words the NPSH available is the full atmospheric pressure plus the depth of submergence. This permits high water velocity through the pump so that the casing size can be minimized. (High suction lift is a condition common with centrifugal pump installations and represents a considerable problem. Also with Mixed-River Pumps it is necessary to place the pumps above river flood level. To avoid cavitations, velocities must be low, increasing the casing size. And the priming and protective devices add to the difficulties of operation and maintenance.

• Back flush: Because there is no need to use a foot-valve, or any kind of valve, it is normal to allow the water in the pump and column to run back after each stop. This has the very beneficial, and necessary effect of flushing trash off the intake strainer and of clearing fibrous material from the impeller and stator. (With the column containing air, the pump is ready for a light-load start).