Bell & Gossett DN0141D Domestic Pump 2′ NPSH Horizontal Pumps Series DB-F - Manual (Page 7)

7
4. Carefully remove pump drain plug and air relief tube. Wait
for complete drainage.
5. Loosen both the discharge connection and the suction
housing to pump volute fasteners. Assure that pressure is
relieved per caution note.
6. Complete the removal of the above hardware. Remove
pump/motor assembly and place on work bench.
7a. Remove the suction housing capscrews and separate the
pump/motor assembly from the suction housing. Note, the
diffuser should separate from the suction housing to allow
the pump/motor assembly to be removed.
7b. Remove propeller, propeller stem and diffuser from the
assembly as follows: Keyed Motor Shafts (5HP and larger).
Remove propeller set screws. Remove propeller, remove
diffuser, and unscrew the propeller stem.
8. Remove capscrews holding motor bracket and pump
volute together. Remove motor and bracket assembly
from volute by lifting straight away from volute.
9. To remove impeller from the motor shaft proceed as
follows: Keyed Shafts. Remove impeller with gear puller or
other means which will not damage impeller or bend motor
shaft.
10. Remove rotating part of seal from shaft, being careful not
to break carbon face.
11. Remove capscrews holding motor bracket to motor and
remove bracket.
12. Remove stationary part of seal assembly, being careful not
to chip or break ceramic seal.
13. To install seal proceed as follows:
(1) Clean recess in bracket thoroughly. Coat recess and
“rubber” portion of seat with soap solution. Press seat
into recess firmly by hand making certain both parts
bottom evenly. If seat cannot be bottomed with fingers
place cardboard shipping disc on ceramic and force
into place with flat tool.
(2) Carefully place bracket into position on motor shaft
without displacing ceramic seat and secure bracket to
motor with capscrews.
(3) Place motor vertically with pump end up. Do
not attempt assembly of seal and impeller with shaft
horizontal.
(4) The “carbon” of rotating part of seal should not be loose.
If it is, hold in place with grease. Using clean, lint free
cloth, wipe mating surfaces perfectly clean. Soap shaft
and push seal onto shaft so that carbon will contact
ceramic seal. If spacer is required, use grease to cause
spacer to adhere to bottom of seal after seal has been
put on shaft. Be sure spacer is on larger diameter of shaft
so that it will not catch between shoulder and impeller.
14. Place impeller on shaft. Make sure impeller is seated.
15. Reassemble volute to bracket.
16. Install stem over drive pin in impeller eye. Tighten lock nut.
17. Set stem to .004 TIR.
18. Install diffuser.
19. Install propeller and tighten set screws.
19a.Install propeller cap and tighten set screws.
20. Using new gasket and noting alignment pin, install assem-
bly on suction housing.
21. Install suction housing and discharge fasteners and tighten.
22. Reconnect pump bleed line and motor wiring.
23. Close drain and slowly open inlet valves.
24. Jog to check motor rotation.
25. Observe operation thru several cycles.
PUMP SERVICE INSTRUCTIONS FOR SERIES HB17 AND HB35 PUMPS cont.’d
CAUTION: DO NOT RUN DRY.
SEAL DAMAGE MAY OCCUR.
Inspect pump seal regularly for leaks. Replace as required.
Failure to follow these instructions could result in injury or
property damage.
WARNING: EXPLOSIBLE
Do not pressurize receiver. Do not plug overflow. Pipe
vent opening to atmosphere. Do not restrict. Open valves
slowly. Failure to follow these instructions could result in
serious injury or death.
CAUTION: DO NOT REVERSE
Reverse operation can cause extensive damage to
pumps. Jog the motor to test for direction of rotation. Failure
to follow these instructions could result in serious injury or
property damage.
MECHANICAL
SEAL
M & R
BRACKET
VOLUTE W/
WEAR RING
IMPELLER
PROPELLER STEM
PIN
WASHER
SET SCREW
PROPELLER CAP
SET SCREW
PROPELLER
SUCTION HOUSING
DIFFUSER
ROTATED FOR CLARITY
DISCHARGE FLANGE
SERIES HB17 CROSS SECTION
SERIES HB-35 CROSS SECTION
LOCKING CAPSCREW
PROPELLER SUCTION
CASTING
PROPELLER CAP
PROPELLER
DIFFUSER
SHAFT EXTENSION
CAUTION: PRESSURIZED SYSTEM
Operating system may contain very hot water under
pressure. Close inlet and open drains before servicing.
When servicing, loosen screws and move components to
assure pressure is relieved before removing screws. Keep
drains open during servicing. Failure to follow these instruc-
tions could result in injury or property damage.