Zenit Group | 04 May 2021
UNIQA CHOPPER
CHOPPER knife shim adjustment
- Lift the pump by the top handle using a hoist of suitable capacity (the weight of the pump is indicated on the rating plate)
- Temporarily fix the knife with 3 screws at 120°
- Loosen the knife lock screws WITHOUT completely undoing them
- Make sure that the knife separates from the pump body by a few millimetres
- Prepare the blades for the adjusting the shim
- Insert the shims at each screw, starting with the thinner ones (0.5 mm)
- Tighten the screws
- Check with a thickness gauge that the shim between knife and blade is between 0.2 and 0.4 mm
- Check the shim also between knife and impeller hub
- Check that it is between 0.3 and 1.4 mm
- If the shim adjustment is not correct, repeat the operation by inserting other shims to obtain different thicknesses
- Once you have found the optimal shim, loosen the knife lock screws
- Use a small slotted screwdriver to loosen the knife from the pump body
- Tack the missing screws WITHOUT tightening them
- Insert the same number and type of shims used for each screw
- Fold the shims inwards so that they do not protrude
- Tighten the knife lock screws by hand in a criss-cross order
- Undo each screw in sequence and re-tighten them by applying Loctite 243 threadlocker or equivalent