Suction Piping; Discharge Piping - Xylem NPE Instruction Manual

2.1.3. Allow adequate space for servicing and
ventilation.
2.1.4. All piping must be supported independently
of the pump, and must "line-up" naturally.
Never draw piping into place by
CAUTION
forcing the pump suction and
discharge connections.
2.1.5. Avoid unnecessary fittings. Select sizes to
keep friction losses to a minimum.
2.2. Close-Coupled Units
2.2.1. Units may be installed horizontally, inclined
or vertically.
Do not install with motor below
CAUTION
pump. Any leakage or condensation
will affect the motor.
2.2.2. Foundation must be flat and substantial to
eliminate strain when tightening bolts. Use
rubber mounts to minimize noise and vibra-
tion.
2.2.3. Tighten motor hold-down bolts before
connecting piping to pump.
2.3. Frame-Mounted Units
2.3.1. It is recommended that the bedplate be
grouted to a foundation with solid footing.
Refer to Figure 1.
(1/4")
Finished grouting
(1/2 to 3/4")
Allowance
for leveling
Wood
frame
Install a pressure relief valve large enough to
limit the system pressure below the maxi-
mum working pressure. Avoid property dam-
age or personal injury caused by incorrect
pressure relief valve adjustment. Pipe the
pressure relief valve discharge to a drain or
other location so that property damage and
flooding will not occur.
2.3.2. Place unit in position on wedges located at
four points (two below approximate center
of driver and two below approximate center
of pump). Adjust wedges to level unit. Level
or plumb suction and discharge flanges.
2.3.3. Make sure bedplate is not distorted and
final coupling alignment can be made within
the limits of movement of motor and by
shimming, if necessary.
2.3.4. Tighten foundation bolts finger tight and
build dam around foundation. Pour grout
under bedplate making sure the areas under
4
Grout hole Base
Grout
Leveling wedges or shims—left in place
Top of foundation—
clean and wet down
Sleeve
Washer
Lug
Figure 1
pump and motor feet are filled solid. Allow
grout to harden 48 hours before fully tight-
ening foundation bolts.
2.3.5. Tighten pump and motor hold-down bolts
before connecting the piping to pump.

3. SUCTION PIPING:

3.1. Low static suction lift and short, direct, suction
piping is desired. For suction lift over 10 feet (3m)
and liquid temperatures over 120ºF (50ºC), consult
pump performance curve for Net Positive Suction
Head Required.
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 re-
ducer (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 valve to
CAUTION
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
priming, 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
connections.
H min.
---------
D
---------
Figure 2
3.0D
min.
1.5D
H min.
min.
min.
D
D D
2
Figure 4
H min.
D
Figure 3
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 10 11 12 13 14 15 16
V = Velocity in feet per second
=GPM x 0.321 GPM x 0.4085
Area D 2
Figure 5