A part of this glossary has been extracted from
the American Standard Glossary of Terms for
Fluid Power (ASA B93.2-1965) with permission
of the publisher, The National Fluid Power
ABSOLUTE TEMPERATUREThe tempera-
ture measured using absolute zero as a reference.
Absolute zero is 273.16°C or 459.69°F.
ACCELERATIONTime rate of change of
ACCUMULATORA device for storing
liquid under pressure. It usually consists of a
chamber separated into a gas compartment and
a liquid compartment by a piston or diaphragm.
An accumulator also serves to smooth out
pressure surges in a hydraulic system.
ACTUATORA device that converts fluid
power into mechanical force and motion.
ADDITIVEA chemical compound or
compounds added to a fluid to change its
AIR, COMPRESSEDAir at any pressure
greater than atmospheric pressure.
AMBIENTSurrounding, such as ambient
air, meaning surrounding air.
BAROMETERAn instrument that mea-
sures atmospheric pressure.
BERNOULLIS PRINCIPLEIf a fluid
flowing through a tube reaches a constriction, or
narrowing of the tube, the velocity of the fluid
flowing through the constriction increases and the
BLEEDER, AIRA bleeder for the removal
BOYLES LAWThe absolute pressure of a
fixed mass of gas varies inversely as the volume,
provided the temperature remains constant.
CAVITATIONA localized gaseous
condition within a liquid stream that occurs where
the pressure is reduced to the vapor pressure.
CELSIUSThe temperature scale using the
freezing point of water as zero and the boiling
point as 100, with 100 equal divisions between,
called degrees. This scale was formerly known as
the centigrade scale.
CENTRIFUGAL FORCEA force exerted
on a rotating object in a direction outward from
the center of rotation.
CHARLESS LAWIf the pressure is
constant, the volume of dry gas varies directly
with the absolute temperature.
CHEMICAL CHANGEA change that
alters the composition of the molecules of a
CIRCUITAn arrangement of intercon-
nected component parts.
COMPRESSIBILITYThe change in volume
of a unit volume of a fluid when it is subjected
to a unit change of pressure.
COMPRESSORA device that converts
mechanical force and motion into pneumatic fluid
COMPUTERA device capable of accepting
information, applying prescribed processes to the
information, and supplying the results of these