HYDAC FILTER SYSTEMS GMBH
Setting up / assembly / integration of the filter unit | 6
BeWa OFU 3120755e en-us print
49 / 84
6.5 Connecting the suction/pressure port
Take into account the pressure loss when connecting suction/
pressure hoses. The suction / pressure hoses from the filter
unit Accessories list are matched to the filter unit.
The pressure loss in a hydraulic line depends upon:
– Flow
– Kinematic viscosity
– Pipe dimensions
– Fluid density
The pressure loss can be estimated as follows for mineral oil-
based hydraulic oils:
Fig. 11:
Pressure loss formula
Δp Pressure differential
[bar]
L Line length
[m]
d Internal pipe diameter
[mm]
Q Flow
[l/min]
ν Kinematic viscosity
[mm²/s]
D Density
[kg/dm³]
The mineral oil-based hydraulic oil has a density of ≈ 0.9 kg/
dm³.
This formula applies to straight pipe runs. Particularly with re-
gard to the suction side connection, note that additional con-
nectors and pipe bends increase the pressure differential.
Observe the following points for hydraulic connection:
– Keep the height difference between the pump and the oil
level in the reservoir as small as possible.
– Use a suction hose that is suitable for a vacuum of ≥
-0.5 bar (e.g. -1 bar).
– Avoid constrictions in the connected hoses. This reduces
the power and increases the risk of cavitation.
1
2
3
4
5
6
7
8
9
10
