DISMANTLING A CENTRIFUGAL PURIFIER FOR SURVEY

• The bowl and its components (disc stack, top disc, bowl hood, distributor) for wear, corrosion, damage, and correct assembly.
• The bowl spindle/ shaft for wear, bending, and correct fit in the bearings.
• The bearings (thrust/ radial) for wear, pitting, damage and correct clearance.
• The drive/ coupling for wear, damage and correct engagement.
• The seals/ gaskets for deterioration and damage.
• The bowl locking/ assembly for correct fit and security.
• The bowl balance/ run-out.
• The condition of the bowl internals (discs, paring disc) for blockage/ damage.
• The overall condition and cleanliness of the purifier.

1. Stop and isolate the purifier; drain the oil and remove the bowl and the drive components to access the vertical shaft and its bearings.
2. Identify the thrust bearings: Note the position, size, type and orientation of the thrust bearings (the upper and lower thrust bearings that locate the vertical shaft axially). Check the bearing identification (part number/ size) against the maker's manual/ spare parts list.
3. Remove the old thrust bearings: Withdraw the old bearings from the shaft/ housing, noting their position and orientation (the thrust face direction).
4. Fit the new thrust bearings: Fit the new bearings in the correct position and orientation (the thrust face must be correctly oriented to carry the axial load), ensuring they are correctly seated.
5. Check the shaft end float/ axial clearance to the maker's specification.
6. Reassemble the purifier (refit the bowl, drive and covers), refill the oil, and run the purifier, checking the operation, vibration and the bearing temperature.
7. Record the bearing replacement (part numbers, date) in the maintenance record.