Please enable JavaScript.
Coggle requires JavaScript to display documents.
Hydraulic Fluids, Hydraulic Fluids - Coggle Diagram
Hydraulic
Fluids
Hydraulic
Fluids
Types
1) Mineral fluids
(
Hydraulic oils
)
Anti-wearing hydraulic fluid
R&O + anti-wearing agents
used in exceeds 14MPa
hydraulic oil HLP
wearing protection
High viscosity index hydraulic fluid
Fluids+ viscosity index improver added
decrease temperature-viscosity changes
hydraulic oil HV
General (R&O) hydraulic fluid
hydraulic oil HL
corrosion protection
ageing stability
Turbine oil-based fluid + prevented rust/ oxidation agents
risk to catch fire on heated metal parts
2) Synthetic fluids
Phosphate hydraulic fluid
fluid + lubricity equivalent
excellent fire resistance
nitrile-butadiene rubber not sealing material
Polyol ester (fatty acid ) hydraulic fluid
less than fire resistance
tolerates epoxy resin paint
nitrile-butadiene rubber sealing material
3) Aqueous fluids
Water + glycolic hydraulic fluid
Water 90 to 95%
W/O emulsions
Water 40%
O/W emulsions
ethylene glycol + water (37 to 40%)
DIN 51524/51525
w/ low inflammability
Anhydrous solutions
(0 - 0.1 %water)
Hydrous liquids
(35-55 %water)
VDMA 24317/24320
HF liquids
HFB (24 317)
HFC (24 317)
HFD (24 317)
HFA (24 320)
Applications
for Hydraulic installations
lubrication for moving parts
cooling prevent pressure losses
decrease pressure jerk
corrosion protection
scuff removal
signal transmission
pressure transfer
for hydraulic oils fulfil
lowest density
minimal compressibility: pressure transfer
not too low viscosity
good viscosity-temperature characteristics
good viscosity-pressure characteristics
good stability
low flammability
good material compatibility: prevent oxidation/rust
air release
non-frothing
resistance to cold
wear/corrosion protection
water separate
Viscosity
mostly important
ISO viscosity classes
(hydraulic oils at 40'C)
ISO VG 22
open air application
ISO VG 32
ISO VG 46
ISO VG 68
ISO VG 100
ISO VG 10
SAE viscosity standard
classes 30
classes 20,20W
classes 10W
classes 5W
Too low viscosity
increased leak
lower efficiency pump/motor
wearing (lock-up)
shortage of oil film
Too high viscosity
decrease fluidity
increase line pressure loss
increase power loss
week responsiveness
pump suction failure
Over 60'C deteriorated oil
15 to 55'C
VI (viscosity index)
high VI
less viscosity-temperature change
multigrade oils