Oil and elements
Oil and elements
(OP)
What benefits do these additives add to a hydraulic oil?
phosphourus
zinc
calcium
silicon
I assume it helps seals and o-rings but I dont know that for a fact.
Thanks,
Kris
phosphourus
zinc
calcium
silicon
I assume it helps seals and o-rings but I dont know that for a fact.
Thanks,
Kris





RE: Oil and elements
The silicon, I don't know why, maybe anti foam?
Regards
pat pprimmer@acay.com.au
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RE: Oil and elements
RE: Oil and elements
RE: Oil and elements
Hydraulic oils, or fluids, have all the characteristics of lubricants: viscosity, VI, oxidation resistance, tribological and anti-corrosion properties, most of those achieved by the additives already mentioned by patprimmer and aviat.
Apart from those characteristics, the specific important features of hydraulic fluis are:
incompressibility, to transmit power successfully; compatibility with seals;
air-release;
filterability;
shear stability in the case of non-Newtonian fluids; and
anti-foam properties (to avoid gas (air) entrapment with an increase in compressibility).
The most important antifoam chemicals to deal with non-aqueous foams are polydimethylsiloxanes, and fluorosilicones. These contain Si, and may be the source of the Si found in the samples, in addition to what aviat has said.
As for the compatibility with elastomeric seals and O-rings, since oils have a tendency to shrink and harden elastomers, a careful balance with polar esters, which are known plasticizers, are formulated.
RE: Oil and elements
All these additives can be found in motor and gear oils, although for hydraulics they're typically at a small fraction of those concentrations.