Goulds Pumps 3640 - IOM - Manual (Page 68)

Maintenance
Impeller replacement
This table shows the criteria for replacing the impeller:
Impeller parts When to replace
Impeller vanes
• When grooved deeper than 1/16 in. (1.6 mm),
or
• When worn evenly more than 1/32 in. (0.8 mm)
Pumpout vanes When worn or bent more than 1/32 in. (0.8 mm)
Vane edges When you see cracks, pitting, or corrosion damage
Wear ring surfaces When the clearance to the casing wear ring has
increased by 50% over the values in the Minimum
running clearances table
Impeller checks
• Check and clean the impeller bore diameter.
• Check the impeller balance. Rebalance the impeller if it exceeds the ISO G1.0 (4W/N)
criteria.
NOTICE:
You must have extremely accurate tooling equipment to balance impellers to the ISO G1.0
criteria. Do not attempt to balance impellers to this criteria unless this type of tooling and
equipment is available.
66 Model 3640 Installation, Operation, and Maintenance Manual