Danfoss APP 1.0 Installation, Operation And Maintenance Manual page 64

Design
1.
Choice of material
.
Rubber
.
Plastic
.
Stainless steel
Always use system components made
of corrosion proof materials
2. Choice of filter
m
< 10 m abs.
Install a 10 micron absolute filter with
pressure switch
3.
Filter location
Locate the return filter in the return line
immediately before the tank
.
Iron
.
Copper
.
Brass
.
Aluminium
Non-corrosion proof materials
may cause damage
m
> 10 m
Return filter with bypass valve and
m
poorer filterability than 10 will
damage the system
Placing the return filter upstream of the
final load may damage the pump
4.
Pump location
Pump always to be placed below water
surface level
5.
Suction conditions
System to be dimensioned to provide
a suction pressure of the pump inlet of
max. 0.1 bar vacuum
6. Pressure Relief valve
Pressure relief valve to be mounted
vertically or with vertical outlet and
connected to return hose or tank
7.
Water supply
System to be filled via filter
Pump location above water surface
level will cause damage
Poor suction conditions will cause
malfunction and damage the pump
Coupling the pressure relief valve outlet
directly to the pump inlet may damage
the pump
Filling system with unfiltered
water causes damage