Bell & Gossett DN0136C Domestic Pump Vacuum Heating Units Series VCL - Manual (Page 10)

10
Closed coupled centrifugal pumps are designed for years of trou-
ble free service. Units have mechanical shaft seals.
1. Close inlet line gate valve and operate pump momentarily to
remove as much liquid as possible from pump. Close dis-
charge line gate valve.
2. Shut-off and lock out power.
3. Make sure unit is cool enough that pump can be handled
safely. Open receiver drain to remove remaining liquid.
4. Carefully remove pump drain plug and bleed line. Wait for
complete drainage.
5. Loosen the motor bracket to pump volute capscrews. 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.
7. Remove self locking stainless steel capscrews and stainless
steel washer (or self locking brass cap nut and washer) that
secure the impeller in place.
8. 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.
9. Remove the rotating part of seal from shaft, being careful not
to break carbon face.
10. Remove capscrews holding motor bracket to motor and
remove bracket.
11. Remove stationary part of seal assembly, being careful not to
chip or break ceramic seal.
12. To install new 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 card-
board 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 it will not catch
between shoulder and impeller.
13. Replace impeller on shaft. Replace stainless steel washer and
secure impeller with capscrew or cap nut.
14. Place new gasket on pump volute and reassemble motor and
pump subassembly on pump volute.
15. Reconnect pump bleed line and motor wiring.
16. Close drain and slowly open inlet valves. See warning.
17. Jog to check motor rotation. See caution.
18. Observe operation thru several cycles.
CAUTION: PRESSURIZED SYSTEM
Operating system may contain very hot water under
pressure. Close inlet and open drains before servicing. When
servicing,
loosen scr ews and move components to assur e
pressure is relieved before r emoving screws . Keep drains
open during servicing. 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.
CAUTION: DO NOT RUN DRY.
SEAL DAMAGE MAY OCCUR.
Inspect pump seal r egularly for leaks. Replace as required.
Failure to follow these instructions could result in injury or
property damage.
W ARNING: HIGH VOLTAGE
Disconnect and lock out power befor e connecting or
sevicing unit. Failure to follow these instructions could result
in injury or property damage.
PUMP SER VICE INSTRUCTIONS MODEL FOR CENTRIFUGAL PUMPS
Vertical mounting puts motor above floor dirt and water
CAUTION: HOT SURFACES
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 injury or property
damage.
W ARNING: EXPLOSIBLE
Do not pr essurize 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.
WATER
SLINGER
VIEW OF
THREADED
IMPELLER
WEAR RING
IMPELLER
2DPF03
VOLUTE
MOTOR BRACKET
MECHANICAL
SEAL
FIG. 13