Teikoku USA | Chempump
Instruction Manual G-Series
25
which would cause rapid bearing wear. Bolt torque values by
model are provided in
Appx. C., Page 31
.
22. Complete reassembly. However, before bolting the pump cas-
ing cover plate to the pump casing, spin the rotor-impeller
assembly by hand to ensure that it does not bind. Also, check
end play again as noted in
Table 4-3
and
4-4
, before reas-
sembling the rear bearing housing to the stator assembly.
23. In reassembling the impeller nut, care must be taken to com-
pletely tighten the impeller lock nut against the impeller to
ensure that it securely holds the impeller against the shaft
shoulder
4.5.6 Models N2S Recommended Tools for
Disassembly
Table 4-8. Recommended Tools
Size
Description
7/16"
Open end, box end wrench for circulation
tube fitting.
5/8" and 11/16"
Open end, box end wrench for the
circulation tube fitting on the pump
casing.
11/16"
Open end, box end wrench for the
circulation tube fitting on the rear bearing
housing.
15/16"
Open end, box end wrench for the pump
casing and front cover plate bolts.
1-1/8"
Drive socket for the impeller nut.
Screwdriver
For front balances plate and seal plate
retaining screws.
4.5.7 Models N2S Disassembly and Reassembly
1. Close discharge valve, shutdown pump, and then close the
suction valve.
2. Disconnect the power cables from the connection box prior
to disassembly.
Hazard!
PERSONNEL SAFETY HAZARD WILL EXIST IF STEP 2 IS
NOT FOLLOWED.
3. Drain pump.
4. Begin disassembly, carefully examining each part for evidence
of corrosion or wear.
5. Remove water jacket or heat exchanger cooling inlet and
drain connections, if used.
6. Remove circulation tube, back flush piping, or reverse circula-
tion piping if so equipped.
7. Remove the bolts holding the rear bearing housing and then
remove the housing.
8. Remove the screw and lockwasher holding the rear bearing to
the rear bearing housing and then remove the rear bearing.
9. Check end play as indicated in
Table 4-3
and
4-4
.
10. Remove the nuts and bolts retaining the front cover plate and
then remove the front cover plate.
11. If a base is provided, loosen one bolt and remove the other
which holds together the upper and lower sections of the
base assembly. Next, pull the pump assembly resting on the
upper half, or cradle portion of the base assembly, away from
the cover plate until the front impeller is clear of the cover
plate. Then rotate the pump assembly and cradle to a point
which will allow further disassembly of the unit. This special-
ly constructed base allows inspection or maintenance to be
performed on the unit without its having to be removed to a
workbench or without the pump assembly having to be set
on the floor or ground. If desired, the motor section can be
removed from the lower base section and taken to another
area for inspection. In this case, the upper half on the base is
used as a stand to protect the parts.
Figure 4-1. General Parts
Circulating Tube Assembly
Pump Casing
Front Gasket
Impeller
Front Bearing Housing
Front Bearing
Base Assembly
Stator Assembly
Rotor Assembly
Rear Bearing
Rear Gasket
Rear Bearing Housing
