Viking Pump TSM141.1: G-LL 125/4125 - Manual (Page 14)

SECTION TSM 141.1 ISSUE E PAGE 14 OF 16
1. Loosen the setscrews over the outer and inner end
caps. Two for G, H and HL size pumps, four for all other
sizes.
2. Turn the inner end cap clockwise, viewed from the shaft
end, until it projects slightly from the bracket exposing
approximately three threads.
3. Turn the outer end cap clockwise until the rotor is tight
against the head and the rotor shaft cannot be turned.
4. Make a reference mark on the bracket end, opposite a
notch on the outer end cap. There are no notches on
G size pumps. Back off the outer end cap the required
number of notches. Refer to Figure 16.
Each 0.25 inch travel on the circumference of the end cap
is equivalent to approximately .002 inch end clearance
for G size pumps and .0015 inch for all other sizes.
5. End clearances set per Step 4 are adequate for
viscosities up to 750 SSU (SAE 20 lube oil at room
temperature). Higher viscosity liquids require additional
end clearances.
As a general guideline, for viscosities between 750 and
7500 SSU (heavier lube oils) double the amount of end
clearance indicated in Step 4; for viscosities between
7500 and 75,000 SSU (e.g., resins) triple the amount
and for viscosities greater than 75,000 SSU (e.g., black
strap molasses) use 4 times the amount.
For specific recommendations for end clearances for
viscosity or for operating temperatures above 225°F,
check with your Viking representative or consult the
factory.
6. Tighten the inner end cap with a spanner wrench. Tap
the spanner wrench lightly but DO NOT OVER TIgHTEN
as it will only damage the threads.
7. Tighten all setscrews that hold inner and outer end caps
to prevent their turning in the bracket.
8. Rotor and shaft should turn smoothly by hand one
complete revolution. If the rotor and shaft doesn’t
turn smoothly, go back and repeat Thrust Bearing
Adjustment Steps 1 through 8.
When installing carbon graphite bushings, extreme care must
be taken to prevent breaking. Carbon graphite is a brittle
material and is easily cracked. If cracked, the bushing will
quickly disintegrate. Using a lubricant and adding a chamfer
on the bushing and the mating part will help in installation.
The additional precautions listed below must be followed for
proper installation:
1. A press must be used for installation.
2. Be certain the bushing is started straight.
3. Do not stop the pressing operation until the bushing is in
the proper position. Starting and stopping will result in a
cracked bushing.
4. Check the bushing for cracks after installation.
Carbon graphite bushings with extra interference fits are
frequently furnished for high temperature operation. These
bushings must be installed by a shrink fit.
1. Heat
the bracket or idler to 750°F.
2. Install the cool bushings with a press.
3. If facilities are not available to reach 750°F. temperature,
it is possible to install with 450°F. temperature; however,
the lower the temperature, the greater the possibility of
cracking the bushing.
Consult the factory with specific questions on high
temperature applications. Refer to Engineering Service
Bulletin ESB-3.
PUMP
SIZE
Turn Outer End Cap C.C.W.
No. of Notches* or Length on O.D., Inches
G — 0.38”
H - HL 3 0.5”
AK - LL 5 0.66”
* Each small notch on outer end cap represents .001
inch end clearance
FIgURE 16
INSTALLATION OF CARBON
gRAPHITE BUSHINgS
THRUST BEARINg ADJUSTMENT