Caution – Xylem IM136 R01 SM Centrifugal Pump User Manual

Page 4

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4.2. If an increaser is required, place between check valve

and pump.

4.3. Use 3 to 4 wraps of Teflon tape to seal threaded

connections.

5. Rotation

5.1. Correct rotation is right-hand (clockwise when

viewed from the motor end). Switch power on and

off quickly. Observe shaft rotation. To change rotation:

5.1.1. Single-phase motor: Non-reversible

5.1.2. Three-phase motor: Interchange any two

power supply leads.

6. Operation

Pumped liquid provides lubrication. If

pump is run dry, rotating parts will seize

and mechanical seal will be damaged. Do not operate

at or near zero flow. Energy imparted to the liquid is

converted into heat. Liquid may flash to vapor. Rotating

parts require liquid to prevent scoring or seizing.
6.1. Before starting, pump must be primed (free of air

and suction pipe full of liquid) and discharge valve

partially open.

6.2. Make complete check after unit is run under

operating conditions and temperature has stabilized.

Check for expansion of piping.

7. Maintenance

7.1. Ball bearings are located in and are part of the motor.

They are permanently lubricated. No greasing required.

8. Disassembly

Complete disassembly of the unit will be described. Pro-

ceed only as far as required to perform the maintenance

work required.
8.1 Turn off power.
8.2 Drain system and flush if necessary.
8.3 Remove motor hold-down bolts.
8.4. Disassembly of Liquid End

8.4.1. Remove casing bolts (370).

8.4.2. Remove back pull-out assembly from casing (100).

8.4.3. Remove impeller locknut (304).

Do not insert screwdriver between impel-

ler vanes to prevent rotation of close-

coupled units. Remove cap at opposite end of motor. A

screwdriver slot or a pair of flats will be exposed. Using

them will prevent impeller damage.

8.4.4. Remove impeller (101) by turning counter-

clockwise when looking at the front of the

pump. Protect hand with rag or glove.

Failure to remove the impeller in a

counter-clockwise direction may damage

threading on the impeller, shaft or both.

8.4.5. With two pry bars 180 degrees apart and

inserted between the seal housing (184) and

the motor adapter (108), carefully separate the

two parts. The mechanical seal rotary unit

(383) should come off shaft with the seal

housing.

8.4.6. Push out the mechanical seal stationary seat

from the motor side of the seal housing.

9. Reassembly

9.1. All parts should be cleaned before assembly.
9.2. Refer to parts list to identify required replacement

items. Specify pump index or catalog number when

ordering parts.

9.3. Reassembly is the reverse of disassembly.
9.4. Observe the following when reassembling the

liquid-end:

9.4.1. All mechanical seal components must be in

good condition or leakage may result. Replace

ment of complete seal assembly, whenever seal

has been removed, is good standard practice.

It is permissible to use a light lubricant, such as

glycerin, to facilitate assembly. Do not contaminate

the mechanical seal faces with lubricant.

9.4.2. Inspect casing O-ring (513) and replace if

damaged. This O-ring may be lubricated with

petroleum jelly to ease assembly.

9.5. Check reassembled unit for binding. Correct as

required.

9.6. Tighten casing bolts in a star pattern to prevent

O-ring binding.

10. Troubleshooting Chart

MOTOR NOT RUNNING

(See causes 1 through 6)
LITTLE OR NO LIQUID DELIVERED

(See causes 7 through 17)
POWER CONSUMPTION TOO HIGH

(See causes 4, 17, 18, 19, 22)
EXCESSIVE NOISE AND VIBRATION

(See causes 4, 6, 9, 13, 15, 16, 18, 20, 21, 22)
PROBABLE CAUSE:

1. Tripped thermal protector
2. Open circuit breaker
3. Blown fuse
4. Rotating parts binding
5. Motor wired improperly
6. Defective motor
7. Not primed
8. Discharge plugged or valve closed
9. Incorrect rotation
10. Foot valve too small, suction not submerged, inlet

screen plugged.

11. Low voltage
12. Phase loss (3-phase only)
13. Air or gasses in liquid
14. System head too high
15. NPSHA too low:

Suction lift too high or suction losses excessive.

Check with vacuum gauge.

16. Impeller worn or plugged
17. Incorrect impeller diameter
18. Head too low, causing excessive flow rate
19. Viscosity or specific gravity too high
20. Worn bearings
21. Pump or piping loose
22. Pump and motor misaligned

CAUTION