PAH SERIES
OM-07186
MAINTENANCE & REPAIR
PAGE E - 24
flush with the undercut end of the sleeve. Slide the
shaft sleeve and rotating portion of the seal onto
the shaft until the sealing faces contact. Continue
to push the shaft sleeve until it seats squarely
against the step on the impeller shaft.
After the impeller has been installed, lubricate the
seal as indicated in
LUBRICATION
.
Impeller Installation
(Figure 5)
Inspect the impeller and replace it if cracked or
badly worn. If removed, install the roll pin (4) in the
hole in the impeller hub.
Install the impeller key (32) in the shaft keyway.
Align the keyway in the impeller with the impeller
key and press the impeller onto the shaft until fully
seated.
Use a piece of soft bar stock or a wood block to pre
vent impeller rotation. Align the hole in the impeller
washer (3) with the roll pin in the impeller and install
the washer. Apply “Loctite Threadlocker No. 243”
or equivalent compound to the threads of the im
peller screw (1). Install the impeller screw and
torque the screw to 250 ft. lbs. (34,5 m. kg.). Re
move the wood block or metal bar used to prevent
impeller rotation.
Pump Casing and Wear Ring Installation
(Figure 4)
If the wear ring (21) was removed, press the re
placement ring into the pump casing until fully
seated. Apply “Loctite Threadlocker No. 243” or
equivalent compound to the threads of the
setscrews (20) and install them in the holes in the
wear ring until snug.
The wear ring
must
seat squarely in the
pump casing or binding and/or excessive
wear will result.
Lubricate the O‐ring (6) with light grease and install
it in the groove in the O.D. of the seal plate.
Carefully position the pump casing over the impel
ler. Install the hardware (7 and 8) on the studs (5)
and use the hardware to draw the pump casing
over the seal plate shoulder until tight.
If removed at disassembly, install the gasket (23)
over the studs (22) and secure the suction spool
(26) to the pump casing with the previously re
moved hardware (7 and 8).
Secure the suction spool to the support assembly
(24) with the previously removed hardware (12 and
25).
Discharge Check Valve Reassembly and
Installation
(Figure 4)
If the discharge check valve (1) was disassembled
to replace the flapper or cover O‐ring, position the
flapper in the valve body and check to ensure free
movement.
Install the valve cover O‐ring and secure the cover
to the body with the previously removed hardware.
Apply a small amount of light grease to the dis
charge flange gasket to hold it in place and posi
tion it against the pump casing flange. Support the
discharge check valve assembly using a sling and
a suitable lifting device. Using the previously re
moved hardware, secure the discharge check
valve assembly and flange gasket to the pump as
sembly (4). Secure the discharge check valve to its
support bracket using the previously removed
hardware.
Priming Chamber Assembly and Installation
(Figure 7)
Clean and inspect the components of the priming
valve (1). Inspect the linkage and ensure the orifice
button (not shown) squarely engages the valve
seat. Replace the orifice button if required (see
Priming Chamber Removal and Disassembly
for orifice button removal).
If the orifice button was removed, screw the new
orifice button into the linkage bar until fully seated.
Align the hole in the linkage bar with the holes in the
bracket and reinstall the pivot pin. Secure the pivot
pin with the previously removed “e‐clip”.
Adjust the orifice button seating as necessary by
screwing the orifice button into or out of the linkage
