Maintenance
d) Install the setscrews (320) and upset threads.
3. Check the casing wear-ring (164) runout and distortion by measuring the bore at each
setscrew location with inside micrometers or vernier calipers.
Machine any distortion in excess of 0.003 in. (0.08 mm) before you trim the new impeller
wear rings (142).
4. Confirm with inside micrometers or vernier calipers the bore of the casing wear rings (164).
5. Turn the impeller wear ring to size after you mount it on the impeller .
NOTICE:
The impeller and wear-ring clearance setting procedures must be followed. Improperly
setting the clearance or not following any of the proper procedures can result in sparks,
unexpected heat generation, and equipment damage.
All replacement impeller wear rings, except those that are hard-faced, are supplied 0.020
in. to 0.030 in. (0.508 mm to 0.762 mm) oversize. See the table Minimum running
clearances for final running clearances. Machine the impeller rings accordingly.
Spare hard-faced impeller wear rings are not supplied oversize but are supplied to pre-
established proper running clearances when both impeller and casing wear rings are
renewed.
When the impeller assembly is supplied as a spare part (impeller with wear rings), the wear
rings are machined to the required dimension.
Model 3610, API Type BB1 API 610 11th Edition Installation, Operation, and Maintenance Manual
79
