Discharge Piping; Rotation; Operation; Maintenance - Xylem GOULDS LB Serie Manuel D'utilisation

3.2 Suction pipe must be at least as large as the suction
connection of the pump. Smaller size will degrade
performance.
3.3 If larger pipe is required, an eccentric pipe reducer
(with straight side up) must be installed at the pump.
3.4 Installation with pump below source of supply:
3.4.1 Install full flow isolation valve in piping for
inspection and maintenance.
DO NOT USE SUCTION ISOLATION
CAUTION
VALVE TO THROTTLE PUMP.
3.5 Installation with pump above source of supply:
3.5.1 Avoid air pockets. No part of piping should be
higher than pump suction connection. Slope
piping upward from liquid source.
3.5.2 All joints must be airtight.
3.5.3 Foot valve to be used only if necessary for prim-
ing, or to hold prime on intermittent service.
3.5.4 Suction strainer open area must be at least
triple the pipe area.
3.6 Size of inlet from liquid source, and minimum sub-
mergence over inlet, must be sufficient to prevent air
entering pump through vortexing. See Figures 2-5.
3.7 Use 3-4 wraps of teflon tape to seal threaded connec-
tions.
H min.
D
Figure 1
3.0D
min.
1.5D
H min.
min.
D min.
D D
2
Figure 3

4. DISCHARGE PIPING

4.1 Allowance should be made for disconnecting dis-
charge piping near casing to allow for pump disas-
sembly.
4.2 Arrangement must include a check valve located
between a gate valve and the pump. The gate valve
is for regulation of capacity, or for inspection of the
pump or check valve.
4.3 If an increaser is required, place between check valve
and pump.
4.4 Use 3-4 wraps of Teflon tape to seal threaded connec-
tions.
4
H min.
D
Figure 2
H
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
V
1 2 3 4 5 6 7 8 9 10111213141516
V = Velocity in feet per second
= GPM x 0.321 GPM x 0.4085
Area D 2
Figure 4

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 rota-
tion:
5.1.1 Single-phase motor: Non-reversible
5.1.2 Three-phase motor: Interchange any two power
supply leads.

6. OPERATION

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 operat-
ing conditions and temperature has stabilized. Check
for expansion of piping.

7. MAINTENANCE

7.1 Ball bearings are located in and are part of the mo-
tor. They are permanently lubricated. No greasing
required.
PUMPED LIQUID PROVIDES LU-
CAUTION
BRICATION. 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 RE-
QUIRE LIQUID TO PREVENT SCORING OR SEIZ-
ING.

8. DISASSEMBLY

8.1 Complete disassembly of the unit will be described.
Proceed only as far as required to perform the main-
tenance work required.
8.1.1 Turn off power.
8.1.2 Drain system and flush if necessary.
8.1.3 Remove motor hold-down bolts.
8.2 Disassembly of liquid end:
8.2.1 Remove casing screws (3).
8.2.2 Remove back pull-out assembly from casing.
8.2.3 Remove nozzle/venturi assembly (6) and
o-rings (5, 7).
8.2.4 Remove guidevane (8).
DO NOT INSERT SCREWDRIVER
CAUTION
BETWEEN THE FAN BLADES TO
PREVENT ROTATION.
8.2.5 Remove impeller (9) by rotating in a counter-
clockwise direction.
NOTE: For single and three phase motors, re-
move the motor end cover and hold the flats on
the shaft with a wrench to stop rotation.