Gorman-Rupp Pumps SF4B 1504502 and up - Manual (Page 36)

SF SERIES OM-06460
MAINTENANCE AND REPAIR PAGE E - 12
Lubricate the I.D. of the bellows with water and
slide the rotating subassembly over the shaft
sleeve (18) until the seal face is just flush with the
undercut end of the sleeve.
Slide the assembled shaft sleeve and rotating por­
tion of the seal and onto the rotor shaft until the pol­
ished faces contact. Continue to push the sleeve
through the seal until it is fully seated against the
shaft shoulder.
Install the seal spring over the bellows retainer and
install the spring retainer (27). See Figure E-3 for
proper order of seal assembly.
Impeller Installation
(Figure E-1)
Inspect the impeller (2) for cracks, broken vanes,
or wear from erosion and replace it if damaged.
Clean the threads in hole in the rotor shaft for the
impeller screw (4).
Install the same thickness of adjusting shims (28)
as previously removed. Install the impeller key (16,
Figure E-2) in the rotor shaft keyway. Align the
keyway of the impeller (2) with the shaft key and
push the impeller onto the shaft until seated firmly
against the upper impeller shim set.
A clearance of .020 to .040 inch (0,51 to 1,02 mm)
between the impeller and the seal plate is recom­
mended for maximum pump efficiency. Measure
this clearance and add or remove impeller adjust­
ing shims as required.
After the impeller is installed, coat the threads of
the impeller screw (4) with `Loctite Threadlocker
No. 242' or equivalent compound. Install the impel­
ler washer (3) and the impeller screw. Wedge a soft
metal bar between the vanes of the impeller to pre­
vent rotation and torque the impeller screw to 27 ft.
lbs. (3,7 m. kg.).
Remove the block of wood and turn the impeller to
check for free rotation.
Suction Head and Wear Ring Installation
(Figure E-1)
The suction head (9) and wear ring (5) must be
installed in the pump casing (1) before installing
the pump casing in order to set the impeller‐to‐
wear ring clearance.
If the wear ring was removed from the suction
head, position the replacement wear ring in the
suction head bore and use an arbor (or hydraulic)
press to press the wear ring into the suction head
until fully seated.
Install a new O‐ring (6) on the shoulder of the suc­
tion head. Position the suction head against the
pump casing and use the hardware (7 and 8A) to
press the suction head into the pump casing.
Adjust the impeller‐to‐wear ring clearance after
installing the pump casing as described below.
Pump Casing Installation
(Figure E-1)
Before installing the pump casing, loosen the jam
nuts (20) and unscrew the capscrews (8) from the
seal plate until they no longer protrude through the
pump casing side of the seal plate.
Install a new O‐ring (15) on the shoulder of the seal
plate. Orient the pump casing (1) as shown in Fig­
ure E-1 and slide it over the seal plate shoulder
until fully seated. Apply “Never‐Seez” or equivalent
compound to the capscrews (11) and use the
hardware (7 and 11) to draw the pump casing over
the shoulder of the seal plate until the wear ring just
touches the face of the impeller.
Finish the face clearance adjustment as described
below.
Impeller Face Clearance Adjustment
(Figure E-1)
A clearance of .006 to .012 inch ( to mm) between
the face of the impeller and the wear ring is recom­
mended for maximum pump efficiency.
Loosen the capscrews (11) securing the pump
casing to the motor assembly. Measure the clear­
ance between the impeller and wear ring. If the
clearance is too narrow, turn the screws (8) in an
alternating pattern to push the pump casing and
suction head away from the impeller until the prop­
er clearance is achieved. If the clearance is too
wide, use the hardware (7 and 11) to draw the