Bell & Gossett DN0412C HS Vented Boiler Feed Units Series HSM - Manual (Page 5)

5
These close coupled vertical centrifugal pumps are equipped with
mechanical seals. If system has not been properly cleaned prior to
installation of pump, foreign matter such as dirt, pipe scale, core sand,
etc. may clog the impeller and damage the seal. A strainer is recom-
mended in return line to pump.
Pump must not be operated dry. Seals
may be damaged if operated without water present.
1. Close inlet line gate valve and operate pump momentarily to
remove as much liquid as possible from pump. Close discharge
line gate valve.
2. Shut-off and lock-out power.
3. Disconnect wiring to motor.
4. Make sure unit is cool enough that pump can be handled safely.
Open receiver drain to remove remaining liquid.
5. Loosen the motor to pump volute fasteners. Assure that pressure
is relieved per caution note.
6. Remove four capscrews (7) holding pump case to motor and lift
motor and impeller out of pump case.
7. Remove pump/motor assembly and place on work bench.
8. Hold top end of motor shaft with large screwdriver via screwdriver
slot in shaft and back off impeller (counter clockwise) with a rec-
tangular bar or other flat tool inserted between the vanesof the
impeller.
9. Remove the rotating part of the mechanical seal from the end of
the shaft.
10. Remove seal holder (2) with stationary ceramic part of mechanical
seal and cup rubber from the end of the shaft.
11. Remove stationary ceramic part of mechanical seal and cup rub-
ber from recess in seal holder.
12. To install new seal, proceed as follows: Clean recess in seal
holder thoroughly. Orient motor so that conduit opening on motor
is to the left when looking at the motor shaft. Replace seal holder
on the face of the motor maintaining concentricity with motor
face. Place new ceramic part of seal in the cup rubber over motor
shaft and press firmly into recess of seal holder by hand, making
certain both parts bottom evenly. If assembly cannot be bottomed
with fingers place a wooden or cardboard tube over shaft onto
ceramic and push into place. Using a clean, lint-free cloth, wipe
the mating surfaces of the seal clean of any foreign matter.
Moisten the carbon section of the rotating part of the seal and
place onto shaft to seat against the ceramic. Place seal spring
onto shaft.
13. Hold motor shaft as described in #8 and replace the impeller on
the shaft (clockwise rotation) making sure it is tight.
14. Orient motor for pump reassembly with conduit opening to the
left. When mounting the pump case, discharge should be 90˚ to
the right of the conduit opening on motor. Use care to insure tight
gasket fit to prevent water leakage.
15. Replace four capscrews (7). Tighten down capscrews evenly to
avoid damage.
16. Reconnect pump bleed line (where applicable) and motor wiring.
17. Close drain and slowly open inlet valves. See warning.
18. Jog to check motor rotation. See caution.
19. Observe operation thru several cycles.
PUMP SER VICE INSTRUCTIONS FOR 609PF CENTRIFUGAL PUMPS
WARNING / HIGH VOLTAGE: Disconnect and lock out
power before connecting or servicing unit. Failure to follow
these instructions could result in serious injury or death.
CAUTION / HOT SURFACES: Surfaces are hot when
system is in operation. Do not touch hot receiver, let unit
cool before servicing. Failure to follow these instructions could
result in injury or property damage.
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 remov -
ing screws. Keep drains open during servicing. Failure to follow
these instructions could result in injury or property damage.
1. Motor
2. Seal Holder
3. Seal
4. Impeller 5. Gasket
6. Case
7. Capscrew
(motor to
volute)
8. Wear Ring
9. Pipe Plug
10. Slinger
1
10
7
3
4
8
6
9
5
2
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.
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 injury or property damage.
WARNING: EXPLOSIBLE
Do not pressurize receiver. Isolate receiver during leak test.
Do not plug overflow. Do not restrict vent opening to atmosphere.
Open valves slowly. Failure to follow these instructions could result
in serious injury or death.