Danfoss APP Series User Manual page 26

Data sheet
8. Noise level
9. Filtration
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6
APP pumps - APP 1.5-3.5
7.2 Storage
Storage temperature:
-40°C to +70°C (+40°F to 158°F) provided that
the pump is drained of fluid and stored
"plugged".
The table indicates the approximate noise level
in dB(A) measured at a distance of 1 m from the
pump in a reverberation room.
Type
APP 1.5
APP 1.8
APP 2.2
APP 2.5
APP 3.0
APP 3.5
Generally, noise will be reduced if speed is
reduced and vice versa. Use flexible hoses in
order to minimize vibrations and noise.
Since the pump is typically mounted on a bell
housing or frame, the noise level must be
determined for the complete unit (system).
It is therefore very important that the motor/
pump unit is mounted correctly on a frame with
antivibration isolation to minimize vibrations and
noise.
As water has very low viscosity, the APP pumps
have been designed with very narrow clearance
in order to control internal leakage rates and
improve component performance. Therefore it is
important that the inlet water is filtered properly
to minimize the wear of the pump.
The main filter must have a filtration efficiency of
99.98% at 10 μm. We recommend to use precision
depth filter cartridges rated 10μm abs. ß10>5000
(equivalent to a filtration efficiency of 99.98%).
Bag filters and string wound filter cartridges
typically have only 50% filtration efficiency. This
means that for each 100,000 particles reaching
180R9267 / IOM APP 1.5-3.5 Appendices - v04 / 11.2013
521B0850 / DKCFN.PD.013.FA6.02 / 09.2012
Frost protection is required at temperatures
below 2°C. Danfoss recommends to use DOW-
FROST from DOW Chemical Company or Chilsafe
mono propylene glycol from Arco Chemical
Company.
60 bar (870 psi) 1500 rpm
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The noise level is influenced by:
• The speed of the pump, high rpm create
more noise than low rpm
• Rigid mounting of the pump generates
more noise than flexible mounting
• Pipe mounting direct to the pump
increases the noise level compared to a
flexible hose
the filter, 50,000 particles pass through it
compared to only 20 particles in a filter with an
efficiency of 99.98%.
For more information on the importance of
proper filtration, please consult our publication
"Filtration" (code number 521B1009), which also
will provide you with an explanation of filtration
definitions and a guidance on how to select the
right filter.
60 bar (870 psi) 3000 rpm
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