Disassembly, Inspection & Reassembly
236 Series Twin-Screw Pump -
Installation, Operation, and Maintenance Manual
63
Body, liner, cover and seal housings areas
Screw shaft inspection
Inspect the screw shafts (100). Repair or replace these parts if you notice any of these
conditions:
•
Localized wear or grooving that is greater than 1.0mm (0.040in) deep
•
Even wear in any location that is greater than 0.5mm (0.020in)
•
Screw edges that exhibit cracks, pitting or corrosion damage.
•
Screw shaft to body clearances that exceed the values in the Minimum running
clearances table by more than 50%.
Check the screw shaft balance. Rebalance the screw shaft if it exceeds ISO 1940-1 grade
16. Note that some pumps are supplied with a higher grade of balance. If in doubt refer to
the original order documentation for guidance.
NOTICE:
Protect machined surfaces while inspecting and cleaning the parts. Failure to do so may result
in equipment damage.
NOTICE:
You must have access to the appropriate accurate fixtures equipment and balance techniques
to successfully balance the screw shafts. Do not attempt to balance the screw shafts unless
the equipment and an approved balance process is available. Failure to follow the correct
process can result in irreversible damage to the screw shaft integrity.
