Xylem AC8584C Series HSCS Base Mounted Centrifugal Pumps - Manual (Page 27)

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ADJUST ABLE WEAR RINGS
Adjustable rings ar e an assembly of two threaded rings. The
outer, stationary ring is held in the casing by a flange and an
anti-rotation pin in the lower half main joint. The inner,
adjustable ring can be move axially, in either direction, by
rotating it. The ring is held in position by a stainless steel lock-
ing pin. All rings have clockwise threads.
Adjustment
When the clearance between the impeller wear face and the
adjustable wearing ring becomes excessive; i.e, approximately
.020" to .030", remove the upper half casing and pull the lock-
ing pin.
Rotate the inner rings clockwise to restore .005"-.008" clear-
ance greater than shaft end float between the ring and the
impeller. Drill a new hole in the inner ring for the locking pin.
This is a blind hole - do not drill through. Replace the locking
pin and upper half casing.
Disassembly and Reassembly
Adjustable ring ar e removed in the same manner as standard
casing rings. They can be separated for cleaning. Adjustable
rings are installed in the pump with stationary and the
adjustable members assembled but not pinned. Turn the
adjustable member counterclockwise to provide maximum
impeller clearance and slide over shaft ends. With the rotating
element in pump, the ring can be adjusted. Be sure that sta-
tionary member has its flange flush against casing lower half.
Move rotating element toward outboard end as far as bearings
permit. Screw outboard end adjustable ring toward impeller to
obtain .005"-.008" axial impeller clearance. Drill through sta-
tionary ring hole into adjustable ring and insert locking pin.
Move rotating element toward coupling and set coupling end
ring in the same manner.
OIL LUBRICA TED BEARINGS
Figur es 25 and 26 show a grease lubricated bearing housing
and an oil lubricated bearing housing, respectively. The main
difference between the two is the grease fitting and the oil
ring, respectively.
FIGURE 24 – ADJUST ABLE WEAR RING
FIGURE 25 – GREASE LUBRICATED BEARING HOUSING
FIGURE 26 – OIL LUBRICATED BEARING HOUSING