The “Pendulum Effect” created by inherently imbalanced, heavy, cast metallic impellers, which are not only hydraulically and mechanically Imbalanced, but often corrode, erode, and cavitate. The imbalance of the metallic impellers (both Hydraulic and Mechanical) in combination with the reduction of bearing supports in metallic pumps being cast overseas today creates a tremendous problem knows as the Pendulum Effect!
Whether the pump is Horizontal, or Vertical, the heavy weight and inherent imbalance of the cast metallic impellers sets up a condition for premature pump failure. Like the Pendulum on a clock, the heavy impeller acts like a weight at the end of the shaft and starts to wobble, or deflect. Any Corrosion, Erosion, or Cavitation increases the Pendulum Effect Problem! The motor bearings cannot hold the stresses that are set up by the Pendulum Effect and the Mechanical Seals, Sleeves, Bushings, Motor Bearings, and Motor fail prematurely. In extreme cases even the shaft break.
This Pendulum Effect is exacerbated by the Hydraulic and Mechanical Imbalance of the impeller. To reduce costs, the impellers are often cast with differences in the vane channels, which causes Hydraulic Imbalance.
Fortunately, the Pendulum Effect is eliminated, with an upgrade to a SIMSITE® Structural Composite Impeller, which is 85% LESS WEIGHT and is 100% machined on 5 to 8 axis machining centers! Additionally, SIMSITE® Impellers & Rings are Perfectly Balanced and remain perfectly balanced for the life of the pump! SIMSITE® Impellers, Casing Rings, and Shaft Stabilizing Bushings are machined on the inside as well as outside from one center position from solid blocks of the patented SIMSITE® Structural Composite. This technology enables the SIMSITE® Structural Composite Impellers to have