Goulds Pumps 3393 - IOM - Manual (Page 78)

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)
Vane edges When you see cracks, pitting, or corrosion damage
Wear ring surfaces When the clearance to the casing wear ring has
increased by 100% over the values in the running
clearances table
76 Model 3393 Installation, Operation, and Maintenance Manual