Bell & Gossett DN0137D Domestic Pump Vacuum & Boiler Feed Unit Series VCMD - Manual (Page 9)

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1. Close pump isolation valve or system return line valve. Operate
pump momentarily to discharge as much water as possible. Close
pump discharge valve.
2. Shut-off and lock out power.
3. Make sure unit is cool enough that pump can be handled safely.
Open drain to remove remaining liquid.
4. Carefully remove pump drain plug and bleed line. Wait for com-
plete drainage.
5. Loosen both the discharge connection and the suction housing to
pump volute fasteners. Assure that the pressure is relieved per
caution note.
6. Complete the removal of the 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 dif-
fuser should separate from the suction housing to allow the
pump/motor assembly to be removed.
(1) Threaded Motor Shafts (3Hp and less). Remove propeller lock
nut. Remove propeller with propeller stem as an assembly with
the diffuser. To install a new propeller, remove the propeller set
screws and separate from the stem.
(2) Keyed Motor Shafts (5Hp and larger). Remove propeller set
screws. Remove propeller, remove diffuser, and unscrew the
propeller stem.
7b. Remove propeller, propeller stem and diffuser from the assembly
as follows:
8. Remove capscrews holding motor bracket and pump volute
together. Remove motor and bracket assembly from the volute by
lifting straight away from volute.
9. To remove impeller from motor shaft proceed as follows:
(1) Keyed Shafts. Remove impeller with gear puller or other means
which will not damage impeller or bend motor shaft.
(2) Threaded Shafts. Hold end of motor shaft opposite pump with
large screwdriver or other suitable tool and back impeller off
with a rectangular bar or other flat tool inserted between the
vanes of the impeller.
10. Remove rotating part of seal from shaft, being careful not 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 seal
cannot be bottomed with fingers place cardboard shipping
disc on ceramic and force into place with flat tool.
(2) Carefully place bracket in 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 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.
CAUTION: PRESSURIZED SYSTEM
Operating system may contain very hot water . Close inlet
and open drains before servicing. When servicing, loosen scr ews
and move components to assure pressure is relieved before r emov-
ing scr ews. Keep drains open during servicing. Failure to follow
these instructions could result in injury or death.
CAUTION: HOT SURFACE
Surfaces ar e hot when system is in operation. Do not touch
hot receiver, let unit cool before servicing. Failure to follow these
instructions could result in serious injury or death.
W ARNING: HIGH VOLTAGE
Disconnect and lock out power befor e connecting servicing
unit. Failure to follow these instructions could result in serious injury
or death.