Xylem AC8584C Series HSCS Base Mounted Centrifugal Pumps - Manual (Page 25)

2 x
ASSEMBL Y (PUMP WITH MECHANICAL SEALS ON SHAFT
SLEEVES)
All bearings, O-rings, seals, gaskets, impeller rings, and cas -
ing wear rings should be replaced with new parts during
assembly. All reusable parts should be cleaned of all foreign
matter before reassembling. The main casing joint gasket can
be made using the lower half as a template. Lay the gasket
material on the casing joint and mark it by pressing it against
the edges of the casing. Trim the gasket so that it is flush with
the inside edges of the casing.
1. Place impeller key (3-911-1) in shaft (3-007-0).
2. Check the impeller (4-002-0) and casing to determine the
correct impeller rotation (See Figure 9) and locate the
impeller on the shaft per dimension “A”. (See Figure 19)
NOTE: For impeller with r
eplaceable rings, heat each new
ring (4-004-9) and slide onto the impeller. Hold rings
against the impeller shoulder until they cool (See Figure
20).
3. Place both shaft sleeve keys (3-911-3) on shaft (3-007-0).
4. Slide sleeve gaskets (1-428-1) onto shaft and against
hubs of impeller.
5. Slide sleeves (3-009-9) onto shaft.
6. Place the sleeve O-ring (3-914-9) onto the shaft, into the
sleeve counterbore. Verify that Dimension “A” (Figure 19)
is maintained, then using a pin spanner wrench and ham-
mer, securely tighten the shaft sleeve nuts (3-015-9).
Then, drill a shallow recess in the shaft through the set
screw hole in each of the shaft sleeve nuts. Lock each
shaft sleeve nut in position with cup point set screws
(3-902-9). (See Figure 21) A low strength sealant, such as
Lotite 271, can be used to retain set screws.
7. Assemble casing rings (3-003-9). (See Figure 24 for
adjustable rings).
8. Install stationary seats (3-401-0) into the glands (3-014-2)
with lapped surface facing outward. Do not scratch or
damage seal faces during assembly. Stationary seat must
bottom squarely in gland.
9. Apply fine coat of silicon grease or equivalent to shaft
sleeve, and slide seal head assembly (3-402-0) over
sleeve. If seal is a John Crane Type 8, set to approximate
dimension shown in Figure 22 and tighten set screws.
Next, install O-rings (3-914-2) onto glands (3-014-2) and
install glands on shaft.
10. Start heating bearings (3-026-2) so that they will be ready
when called for in step 11. Use dry heat from induction
heat lamps or electric furnace, or a 10-15% soluble oil
and water solution.
11. Assemble oil seal (3-177-9) in each bearing cover. Install
gaskets (3-409-9) on each bearing cover.
NOTE: Seal lip or pr essure side of oil seal must point
towards the ends of the shaft that the oil seal is assem-
bled on. (See Figures 25 and 26)
12. Slide deflectors (3-136-9) and bearing covers (3-018-3,
-4) on the shaft. Install snap rings (3-915-9). Install thrust
washer (3-078-9) on the outboard end.
For ease of assembly and protection of rubber parts while
sliding parts onto shaft, cover O-ring groove, keyways,
and threads with electrical tape.
CAUTION:
Do not use petr
oleum based products for installing
mechanical seal head as it may attack the rubber elast-
omers.
CAUTION:
DO NOT EXCEED 275ºF
.
CAUTION:
These ar
e precision, high quality bearings. Exercise
care at all times to keep them clean and free from foreign
matter.
FIGURE 21 – DRILLING SET SCREW RECESS