OM-07264
S SERIES PUMPS
PAGE E - 11
MAINTENANCE AND REPAIR
the O‐ring is properly positioned and has not been
cut. Remove the tissue and wipe the face.
Diffuser Installation
(Figure 1)
Replace the intermediate O‐ring (4)
With the seal seat and stationary element installed,
carefully lower the diffuser (1) over the shaft until
the stationary element mates with the rotating ele
ment. Secure the diffuser with the special studs
(47).
Do not overtighten the special intermedi
ate studs. Overtightening may cause the
threads in the intermediate to strip out.
Impeller Installation
(Figure 1)
Inspect the impeller (2) for cracks, broken vanes,
or wear from erosion, and replace it if damaged.
Clean the threads on the rotor shaft to remove any
old thread locking material. Be sure the impeller
bore and the shaft are free of oily film and com
pletely dry.
Install the same thickness of impeller adjusting
shims (54) as previously removed. Install the im
peller key (52). Align the keyway of the impeller (2)
and push the impeller onto the shaft until seated
firmly against the shim set. Install the impeller
washer (50) on the rotor shaft (33).
After
the impeller is installed, coat the threads of
the rotor shaft with `Loctite Threadlocker No. 242'
or equivalent compound. Install the impeller nut
(51). Wedge a block of wood between the vanes of
the impeller and intermediate studs (47) to prevent
shaft rotation, and torque the nut to 60 ft. lbs. (720
in. lbs. or 8,3 m. kg.).
NOTE
The clearance between the face of the impeller and
the suction head can only be measured after the im
peller and suction head are fully installed.
Remove the block of wood and turn the impeller to
check for free rotation.
NOTE
After the impeller has been properly positioned,
check for free rotation. Correct any scraping or
binding before further reassembly.
Strainer Plate And Suction Head Installation
(Figure 1)
Thoroughly clean the strainer plate (41) and suc
tion head (53). Inspect the parts for cracks, distor
tion or erosion, and replace if defective. It must be
clean and free of any flaws which could prevent a
good seal.
Position the suction head on the studs (47). After
the impeller clearance is checked (see
Impeller
Clearance
), apply `Never‐Seez' or equivalent
compound to the threads of the studs. Install the
special washers (48) over the studs with the flat
edge toward the outer diameter of the suction
head. Secure the suction head by torquing the hex
nuts (49) evenly in a cross sequence to 20 ft. lbs.
(240 in. lbs. or 2,8 m. kg.).
Install the strainer plate gasket (5). Install the
strainer plate around the suction head. Align the
holes for the capscrews (44) in the strainer plate
with those in the intermediate (8).
Impeller Clearance
(Figure 1)
For maximum pump efficiency, there should be a
clearance of .003 to .010 inch (0,07 to 0,25 mm) be
tween the suction head and the face of the impeller.
Use a feeler gauge to measure this clearance. If the
clearance is not within the specified limits, remove
the suction head and impeller. Add or remove ad
justing shims (54) as required. Install the impeller
and suction head and recheck impeller clearance.
