Shimming

Installing a hose correctly also involves correct shimming. The instructions from the manufacturers are often not clear or even incorrect. Follow the following steps for a more complete measurement.

1. Tolerances (Hose, Pump House, Rotor, Pressing Shoe/Roller) – Measure A Dimension in 3 locations and take the largest number!

2. Hose Finish: Wrapped vs. Rectified Hose (There is a difference in the number of shims to be needed.

3. Peristaltic Hose Tolerances (Always check the new hose!)

4. Hose Material Expansion with Warm Product Transfer

5. The speed of the pump also changes the number of shims needed – always shim for the lowest speed!

6. The ΔP = Discharge Pressure − Suction Pressure of the pump – ensure you have both inlet and discharge pressures at Peak Pressures (that is the Pulsation Pressure)

7. Viscosity: Resistance in Small Cavities for Backflow

Below is the Shimming Calculator (first version) to calculate the shimming.