Notes On Pipes And Hoses - HYDAC FILTER SYSTEMS MRFD2N Installation And Maintenance Instructions Manual

MRFD2N

Notes on pipes and hoses

In order to keep the pressure loss as low as possible, use as few threaded
connections as possible.
The pressure loss in a hydraulic line depends upon:

Flow Rate

Kinematic viscosity

Pipe dimensions

Fluid density
The pressure loss can be estimated for hydraulic oils as follows:
Δ = Pressure differential in [bar]
p
L = pipe length [m]
d = internal pipe diameter [mm]
Q = Flow rate [l/min]
V = Kinematic viscosity [mm²/s]
D = Density [kg/dm³]
This applies to straight pipe runs and hydraulic oils. Additional threaded connections
and pipe bends increase the pressure differential.
Keep the height difference between the pump and the oil level in the tank as low as
possible.
Hoses must be suitable for suction pressures of at least -0.5 bar.
Constrictions in the connections and lines should be avoided. This could
compromise suction output and cause cavitation .
Take note that the nominal size of the connected hoses/piping must be at least as
large as the inlet port sizes.
Make sure that no tension or vibrations are carried over to the pump or filter housing
when the pipes are connected. Use hoses or expansion joints if necessary.
HYDAC FILTER SYSTEMS GMBH
MoWa MRFD2 3312153b en-us 2012-08-08.doc
Δp ~ 6.8 * L / d
Mineral oil-based hydraulic fluid has a density
of ~ 0.9 kg/cm³.
en(us)
Hydraulic connection of the MRF
4
* Q * V * D
Page 24 / 32
2012-08-08