23
Choice of hydraulic fl uid
Down rating of pressure, for motors used in systems
with fi re resistant fl uids, the maximum pressure for
motor given on data sheet must be multiplied with
following factors:
HFA-fl uid not fi t for use
HFB-fl uid 0,7 x maximum pressure for motor
HFC-fl uid 0,7 x maximum pressure for motor
HFD-fl uid 0,9 x maximum pressure for motor
Down rating of basic rating life, for motors used in
systems with fi re resistant fl uids, the "expected basic
rated life" must be multiplied with following factors:
HFA-fl uid not fi t for use
HFB-fl uid 0,26 x expected life with mineral oil
HFC-fl uid 0,24 x expected life with mineral oil
HFD-fl uid 0,80 x expected life with mineral oil
Down rating of pressure data and basic rating life
The oil in a hydraulic system must always be fi lte red and also new oil from your supplier has to be fi ltered
when adding it to the system. The grade of fi ltration in a hydraulic sys tem is a question of ser vi ce life v.s.
money spent on fi lt ra tion.
In order to obtain stated service life it is important to follow our recommendations concerning con tami na tion
level.
When choosing the fi lter it is important to consider the amount of dirt particles that the fi l ter can absorb and
still operate satisfactory. For that rea son we recommend a fi lter with an indicator that gi ves a sig nal when
it is time to change the fi lter cartridge.
Filtering recommendations
Before start-up, check that the system is thoroughly cleaned.
1. In general the contamination level in our motors should not exceed ISO 4406 19/15 (NAS 10).
2. For heavy-duty applications the con tami na tion level should not exceed ISO 4406 16/13 (NAS 7).
3. When fi lling the tank and motor case, we recommend the use of a fi lter with the grade of fi ltration
β10=75.
Filtration
Explanation of "Grade of Filtration"
Grade of fi ltration β10=75 indicates the following:
β10 means the size of particle ≥10µm that will be removed by fi lt ra tion.
=75 means the grade of fi ltration of above mentio ned size of particle. The grade of fi ltration is defi ned as
number of particles in the oil before fi ltration in relation to number of particles in the oil after fi ltration.
Ex. Grade of fi ltration is β10=75.
Before the fi ltration the oil contains N number of particles ≥10µm and after passing the fi lter once the oil
contains number of particles ≥10µm.
This means that number of particles have been fi ltered (=98,6%).
To Next Page
Loading...
Need help?
General
