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
English
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