52 | 180R9346 | AQ240486503020en-001702
© Danfoss | 2023.03
Operation guide
Installation, Operation and Maintenance APP 53-92 pumps
6. Operation
6.1 Temperature
6.2 Pressure
The inlet pressure shall be min. 2 barg (30 psig)
and max. 5 barg (72.5 psig). At lower pressures
the pump will cavitate, resulting in damage of
the pump.
Max. inlet pressure peak (e.g. in case the pump
stops momentarily) up to 10 barg (145 psig) are
acceptable.
Max. pressure on the pump’s outlet line shall be
limited at 80 barg (1160 psig) continuously.
For APP 86 min. inlet pressure shall be 2.5 barg
(36 psig) and max. outlet pressure shall be
70 barg (1015 psig).
For APP 92 min. inlet pressure shall be 3.5 barg
(50 psig) and max. outlet pressure shall be
70 barg (1015 psig).
Note: The pump unit should include a pressure
gauge on the high-pressure side.
6.3 Dry running
When running, the pump must always be
connected to the water supply in order to avoid
damage if it should run dry.
6.4 Disconnection
If the inlet line is disconnected from the water
supply, the pump will be emptied of water
through the disconnected inlet line.
When starting up again, follow the bleeding
procedure described under section 4: Initial
start up.
Fluid temperature:
Min. +2°C to max. +50°C
(Min. +35.6°F to max. +122°F)
Ambient temperature:
Min. +2°C to max. +50°C
(Min. +35.6°F to max. +122°F)
In case of lower operating temperatures, please
contact Danfoss High Pressure Pumps.
The chart below illustrates the corrosive
resistance of different types of stainless steel
related to NaCl concentration and temperature.
The APP water pump is made of Duplex and
Super Duplex.
If the water pump is operated above the Super
Duplex line, always flush water pump with fresh
water at operation stop in order to minimize the
risk of crevice corrosion.
NaCl vs. temperature
316L
Super Duplex
80 º
C
70
60
50
40
30
20
100
160
1600
1000
16000
10 000
160000
100 000
CI -
ppm
NaCI
ppm
Duplex