Wilo NPG Series Installation And Operating Instructions Manual page 10

4.4 Piping
Protective covers are fitted to the pipe
CAUTION!
connections to prevent foreign bodies
entering during transportation and
installation. Ensure that these covers are
removed from the pump before connec-
ting any pipes.
4.4.1 Suction and discharge pipework
The dimensions of the pipes do not directly
depend on suction and discharge diameters of the
pump.
a) First, choose a flow speed < 2 m/s at suction,
and about 3 m/s at discharge.
b) Take into account the available NPSH, which
must be superior to the required NPSH of the
pump.
Flange
Vertical Discharge
Horizontal Suction
Forces and moments values are applied to the
whole flanges and not flange-by-flange. For their
sharing out on the pump flanges, refer to standard
NFCR 13 931.
Ensure piping and fittings are flushed
CAUTION!
before use.
Installation and maintenance instructions Wilo-Horizontal pumps
DN Forces (daN)
Fy Fz
150 160 200
200 215 265
250 270 335
300 320 400
350 375 465
400 430 530
450 485 600
500 540 665
150 180 160
200 240 215
250 300 270
300 360 320
350 420 375
400 480 430
450 540 485
500 600 540
Never use pump as a support for piping. Do not
mount expansion joints in such a way that their
force, due to internal pressure, may act on the
pump flange.
Maximum forces and moments allowed on the
pump flanges vary with the pump size and type.
These external strains may cause misalignment,
hot bearings, worn couplings, vibrations and the
possible failure of the pump casing.
When designing the pipes (§ 4.4.2.1, § 4.4.2.2,
§ 4.4.3.1) take necessary precautions in order not
to exceed maximum allowed strains.
Forces and moments applied to the pump flanges
must never exceed the values shown in the table
below:
Fx F My
180 310 45
240 415 85
300 520 125
360 625 170
420 730 220
480 835 275
540 940 340
600 1040 410
200 315 45
265 415 85
335 520 125
400 625 170
465 730 220
530 835 275
600 940 340
665 1040 410
Ensure piping for hazardous liquids is
CAUTION!
arranged to allow pump flushing before
removal of the pump.
4.4.2 Suction piping
4.4.2.1 Design of a flooded suction line
The suction line must be as short and direct as
possible, never mount an elbow directly on the
NPG
Moments (m.daN)
Mz Mx M
60 80 110
100 125 180
145 180 260
200 240 355
255 310 455
320 390 570
390 480 705
470 580 850
60 80 110
100 125 180
145 180 260
200 240 355
255 310 455
320 390 570
390 480 705
470 580 850
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