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Fig. 8 Deaeration
Fig.7 Suction line
Fig. 6 Pipe connections
For direct driven pumps the alignment between
pump and motor shafts must be kept within the
following limits:
Max run-out
Max angular
misalignment
(mm)
(degrees)
Type LPD
and ACD
(n/a short coupled)
Other types 0.3
0.1
Fig 5.
!
When handling liquids which may involve
fire hazards appropriate precautions to
avoid danger are to be taken.
!
Measures shall be provided to avoid
accidental contact with the rotating shaft
coupling. Any installed coupling guard
shall permit easy access to the pump
shaft for maintenance and inspection of
the pump bearing and seal housing.
Pipe connections
The pipe work shall be installed and supported so
that no pipe stresses are transfered to the pump
body.
The pipe work should be tight in order to avoid
leakage and infiltration of foreign particles and/or air.
Shut off valves should be installed in both suction
and discharge pipes, so that the pump can be
hydraulically isolated.
Suction line
The suction pipe should be designed so that the
total pressure drop, measured at the pump inlet
flange, does not exceed the suction capability of the
pump.
Make a proper calculation of the suction line
including components such as valves, strainer,
pipe bends etc. Generally, the pressure drop in the
suction line should be as low as possible, which is
achieved if the suction pipe is short, straight and has
a suitable diameter.
The velocity in the suction line should be kept in the
range 0.5 - 1.2 m/s. For L.O. circulating systems, we
recommend to keep it as low as possible.
The suction line must be equipped with a port that
allows filling the pump before start.
Discharge line
The discharge line should be dimensioned to keep
the velocity in the range 1 - 3 m/s.
Deaeration
In installations with negative suction head, where
the pump might be started against a pressurized
system, a deaeration pipe with an orifice (2-3 mm
recom mended) has to be installed. The deaeration
pipe should be connected to the outlet pipe’s highest
point.
This must also be installed when the pump is used
as an stand-by pump.
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