HYDRAULIC
FLUID
Hydraulic system
liquids are used
primarily to transmit
and distribute forces
to various units
to be actuated. Liquids are
able to do
this because they
are almost incompressible. Pascal’s Law
states that pressure
applied to any
part of a
confined liquid is
transmitted with undiminished
intensity to every
other part. Thus if
a number of
passages exist in
a system pressure
can be distributed
through all of
them by means
of the liquid.
Manufactures of
hydraulic devices usually
specify the type
of liquid best
suited for use
with their equipment, in
view of the
working conditions, the service
required, temperature
expected inside and
outside the systems, pressure the
liquid must withstand, the possibilities
of corrosion and
other conditions that
must be considered. Some of
the properties and
characteristics that must
be considered when
selecting a satisfactory
liquid for a
particular system are
discussed below.
