501-C00 Page 11/12
MAINTENANCE
14. Rotate the shaft by hand to engage the mechanical seal
drive tangs, and to test for binding or tight spots. If the
rotor does not turn freely, lightly tap the rims of the heads
with a soft faced mallet until the correct position is found.
Install all of the remaining head capscrews (21) for each
head (20) and uniformly torque to 30 lbs ft (40.7 Nm).
15. LOCKNUT ADJUSTMENT
It is important that the bearing locknuts (24A) and
lockwashers (24B) be installed and adjusted properly.
Overtightening locknuts can cause bearing failure or a broken
lockwasher tang. Loose locknuts will allow the rotor to shift
against the discs (71), causing wear. See Figure 11.
Figure 11 - Locknut Adjustment
a. On both ends of the pump shaft, Install a lockwasher
(24B) with the tangs facing outward, followed by a
locknut (24A) with the tapered end inward. Ensure the
inner tang "A" of the lockwasher is located in the slot in
the shaft threads, bending it slightly, if necessary.
b. Tighten both locknuts (24A) to ensure that the bearings
(24) are bottomed in the head recess. DO NOT
overtighten and bend or shear the lockwasher inner
tang.
c. Loosen both locknuts one complete turn.
d. Tighten one locknut until a slight rotor drag is felt when
turning the shaft by hand.
e. Back off the nut the width of one lockwasher tang "B".
Secure the nut by bending the closest aligned
lockwasher tang into the slot in the locknut. The pump
should turn freely when rotated by hand.
f. Tighten the opposite locknut (24A) by hand until it is
snug against the bearing (24). Then, using a spanner
wrench, tighten the nut the width of one lockwasher
tang. Tighten just past the desired tang, then back off
the nut to align the tang with the locknut slot. Secure the
nut by bending the aligned lockwasher tang into the slot
in the locknut. The pump should continue to turn freely
when rotated by hand.
g. To check adjustment, grasp the nut and washer with
fingers and rotate back and forth. If this cannot be done,
one or both locknuts are too tight and should be
alternately loosened one stop at a time (.001" – 25
microns). Begin by loosening the locknut adjusted last.
16. Inspect the grease seal (104) for wear or damage and
replace as required. Grease the outside diameter of the
grease seal and push it into the inboard bearing cover
(27) with the lip of the seal inward.
17. Attach a new bearing cover gasket (26) and the bearing
cover (27) to the inboard head (20). Make sure the
grease fittings (76) are accessible. Install and torque the
bearing cover capscrews (28) to 30 lbs ft (40.7 Nm).
18. Install the grease seal (104) and bearing cover (27) on
the opposite side of the pump as instructed in steps 16
and 17.
19. On 2-inch pump models, push the dirt shield (123A) over
the inboard and outboard shafts and firmly against the
bearing cover (27).
20. Attach the shaft protector (186) to the non-driven shaft
end of double ended pumps.
Operation without guards in place can
cause serious personal injury, major
property damage, or death.
Do not operate
without guard
in place
21. See "Pre-Start Up Check List" and "Start Up Procedures"
sections of this manual prior to restarting pump operation.
TROUBLESHOOTING
NOTICE:
Maintenance shall be performed by qualified technicians only,
following the appropriate procedures and warnings as presented in this manual.
SYMPTOM
PROBABLE CAUSE
Pump Not Priming
1. Pump not wetted.
2. Worn vanes.
3. Internal control valve closed.
4. Strainer clogged.
5. Inlet line or valves clogged or too restrictive.
6. Pump vapor-locked.
7. Pump speed too low for priming.
8.
Relief valve partially open, worn or not seating properly.
Reduced Capacity
1. Pump speed too low.
2. Internal control valve not fully open.
3. Excessive restriction in the inlet line (i.e.: undersized piping, too many elbows & fittings,
clogged strainer, etc.).
4. Damaged or worn parts (vanes, cylinder, or rotor).
5. Excessive restriction in discharge line causing partial flow through the relief valve.