Danfoss APP 5.1 User Manual page 26

Data sheet
9. Filtration
10. Dimensions
6 8
APP pumps - APP 5.1-10.2
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
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 that you 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 90% filtration
efficiency. This means that for each 100,000 parti-
cles reaching the filter, 10,000 particles pass
through it compared to only 20 particles in a
filter with an efficiency of 99.98%.
10.1 APP pump
180R9263 / IOM APP 5.1-10.2 Appendices - v02 / 01.2013 521B0851 / DKCFN.PD.013.FB3.02 / 10.2012
For more information on the importance of
proper filtration, please consult our publication
"Filtration" (code number 521B0861), which also
will provide you with an explanation of filtration
definitions and a guidance on how to select the
right filter.