Hydraulic Balancing Devices

Abstract

A single-suction impeller is subject to axial hydraulic thrust caused by the pressure differential between its two faces. If all the single-suction impellers of a multistage pump face in the same direction, the total theoretical hydraulic axial thrust acting toward the suction end of the pump will be the sum of the individual impeller thrusts. The thrust magnitude (in pounds) will be approximately equal to the product of the net pump pressure (in pounds per square inch) and the annular unbalanced area (in square inches). Actually the axial thrust turns out to be about 70 to 80 percent of this theoretical value (see Chap. 5).