Goulds Pumps 3640 - IOM - Manual (Page 74)

Maintenance
c) Chill the new casing wear ring (164) using dry ice or other suitable chilling substance,
and install the ring into the fit of the casing (100).
Be prepared to tap the ring in place with a hardwood block or soft-faced hammer.
WARNING:
Dry ice and other chilling substances can cause physical injury. Contact the supplier for information and
advice for proper handling precautions and procedures.
d) Chill the head wear ring (164A) using dry ice or other suitable chilling substance, and
install the ring into the fit of the head (184).
Be prepared to tap the ring in place with a hardwood block or soft-faced hammer.
e) Chill the spacer bushing (206) using dry ice or other suitable chilling substance, and
install the bushing into the fit of the casing spacer (443D).
Be prepared to tap the ring in place with a hardwood block or soft-faced hammer.
f) Locate, drill, and tap three new setscrew holes equally spaced between the original
holes in each new ring and ring seat area and in each new bushing and bushing seat
area.
g) Install the setscrews (320) and upset threads.
3. Check the casing and head wear-ring (164, 164A), and bushing spacer (206) runout and
distortion by measuring the bore at each setscrew location with inside micrometers or
vernier calipers.
Any distortion in excess of 0.003 in. (0.08 mm) should be corrected by machining prior to
trimming the new impeller wear rings (142), if supplied.
4. Confirm the bore of the casing and head wear rings (164, 164A) and bushing spacer (206).
5. Turn the impeller wear ring (142, 144) to size after you mount it on the impeller (101, 145).
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.
72 Model 3640 Installation, Operation, and Maintenance Manual