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Bell & Gossett DN0129D Series CMU User Manual

Page 6

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6

PUMP SER

VICE INSTRUCTIONS FOR UNDERGROUND CENTRIFUGAL PUMPS

Vertical mounting puts motor above floor dirt and water.

These instructions ar

e for pump disassembly. The mechanical seal

can be replaced without complete pump disassembly as detailed
on the prior page.

1. Close inlet 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.

4. Loosen the discharge pipe. Assure that pressure is relieved per

caution note.

5. Disconnect motor leads, conduit and discharge pipe.

6. Remove coverplate and pump assembly.

7. Remove discharge connection and tubing.

8. Remove capscrews holding volute and lower bearing head.

9. To remove impeller from motor shaft proceed as follows:

a) Remove self locking capnut and washer or self locking cap-

screw and washer.

b) Hold end of shaft opposite pump with suitable tool and

back impeller off with a rectangular bar or other flat tool

inserted between the vanes of the impeller.

10. Remove motor from motor support (half of the flexible coupling

will come away with the motor) and set aside.

11. Remove remaining part of flexible coupling. Use puller.

12. Remove grease coverplate from bearing support.

13. Remove the snap-ring from above the bearing.

14. Remove the four capscrews that hold the bearing support.

15. Insert two screws

3

/

8

x 16 at least 1

1

/

2

" long, into the tapped

holes in the flange around the bottom of the bearing support,
remove the bearing support by turning both screws evenly, or
by alternating half-turns.

16. With the bearing support freed, remove the stationary part of

the seal, the slinger, and the bearing from the bearing support.
Remove the old gasket.

17. Remove bearing (note: bearing is shielded on lower side).

18. Remove rotating part of seal from shaft. Remove collar when

replacing shaft only.

19. Reassemble pump using new gaskets, reversing procedure

and following mechanical seal replacement steps described on
prior page.

20. When replacing lower bearing, remove lower carbon bearing

from lower bearing head and install new bearing.

Note: If lower bearing is made of br

onze, then a complete new

lower bearing head assembly is required.

21. Reconnect pump bleed line and motor wiring.

22. Slowly open inlet gate valve. See warning.

23. Jog to check motor rotation. See caution.

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

assure pressure is relieved before

r

emoving

scr

ews. Keep

drains open during servicing. Failure to follow these instruc-
tions 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.

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.

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 serious
injury or death.

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.

COLLAR
FLOAT STOP

2DPU02

2DPU04

FLOAT ROD

FLOAT

COLLAR
FLOAT STOP

FLOAT ROD GUIDE

GASKET CASE

IMPELLER
BRONZE ENCLOSED

ORIFICE

ORIFICE

DRAIN PLUG

CASE RING BRASS

CASE

DISCHARGE ELBOW

LOWER BEARING
HEAD

PUMP SUPPORT
COLUMN. PILOTED

DISCHARGE PIPE

INTERMEDIATE
BEARING HOUSING

WHEN USED

INLET

DRAIN PLUG

CASE RING BRASS

CASE

INTERMEDIATE
BEARING OIL-LESS

WHEN USED

LOWER BEARING
OIL-LESS

DISCHARGE ELBOW

LOWER BEARING
HEAD

LOWER BEARING
OIL-LESS

PUMP SUPPORT
COLUMN. PILOTED

DISCHARGE PIPE

INLET

IMPELLER SHAFT
STAINLESS STEEL

SEAL LUBRICATING
ASSEMBLY (WATER)

"O" RING
DISCHARGE FLANGE

EXPANSION JOINT

GASKET
DISCHARGE FLANGE

DISCHARGE FLANGE

GASKET
MOTOR SUPPORT

MOTOR SUPPORT

MECHANICAL SEAL

THRUST BALL BEARING WITH
SINGLE SEAL AND PROVISION
FOR RELUBRICATION

FLEXIBLE COUPLING

CUSHION SPIDER

MOTOR

GREASE CUP

FLOAT SWITCH

AUTOMATIC
ALTERNATOR

DUPLEX UNITS ONLY

SWITCH BRACKET

COLLARS (2)
SWITCH DRIP

VAPOR SEALS (2)

PIPE NIPPLE

RETAINING RING SHAFT

BEARING COVER

BEARING HOUSING

AIR VENT

CONTROL BASE

GASKET
CONTROL BASE

COVER PLATE

GASKET
RECEIVER

SLINGER

STOP COLLAR
MECHANICAL SEAL

RECEIVER CAST IRON

COLLAR
FLOAT STOP

FLOAT ROD

FLOAT

ORIFICE

COLLAR
FLOAT STOP

FLOAT ROD GUIDE

GASKET CASE

IMPELLER
BRONZE ENCLOSED

ORIFICE

KEYS (2)

SET SCREWS (2)

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