3 initial alignment, 4 piping – Flowserve NMD User Manual

Page 15

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NMD, NMAD USER INSTRUCTIONS ENGLISH 71576436 - 11/09


Page 15 of 40

4.3 Initial alignment

Before connecting the couplings

verify the motor rotation direction.

4.3.1 Thermal expansion

The pump and motor will normally

have to be aligned at ambient temperature and
should be corrected to allow for thermal expansion
at operating temperature. In pump installations
involving high liquid temperatures, the unit should be
run at the actual operating temperature, shut down
and the alignment checked immediately.

4.3.2 Alignment methods

Ensure pump and driver are isolated

electrically and the half couplings are disconnected.
Ensure that the pump pipework, suction and
discharge, is disconnected.

The alignment MUST be checked.


Although the pump will have been aligned at the
factory it is most likely that this alignment will have
been disturbed during transportation or handling. If
necessary, align the motor to the pump, not the
pump to the motor.

Alignment
Parallelism and concentricity check:

Check the alignment at three or four

points, before pipeworks assembly.

with a rule

with a comparator

Admissible margin for a motor with roller bearings:
= 0.15 mm parallel checking
= 0.1 mm angular checking

Angular checking:

with a sliding rule

with a caliper gauge

The alignment will be definitive only

after pipework connection (see § 4.4.1).

Never connect the electric motor

before the setting has been completely finished.

4.4 Piping

The user must verify that the equipment is

isolated from any external sources of vibration.

Protective covers are fitted to the

pipe connections to prevent foreign bodies entering
during transportation and installation. Ensure that
these covers are removed from the pump before
connecting 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.

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:

Forces (daN)

Moments (m.daN)

Pipework

arragement

D

N

fl

a

n

g

e

s

F

Y

F

Z

F

X

F

M

Y

M

Z

M

X

M

100

50

40

45

80

18

20

25

37

125

62

55

55

100

22

26

31

46

150

75

60

81

120

22

31

37

55

200 100

81

90

157

34

39

48

72

250 125 100 112 195

43

49

60

89

Suction and

discharge

300 150 121 135 235

65

74

91

134

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