DENSITYThe weight per unit volume of a
DIAGRAM, COMBINATIONA drawing
using a combination of graphical, cutaway, and
DIAGRAM, CUTAWAYA drawing show-
ing principal internal parts of all components,
controls, and actuating mechanisms, all inter-
connecting lines and functions of individual
DIAGRAM, GRAPHICALA drawing or
drawings showing each piece of apparatus
including all interconnecting lines by approved
DIAGRAM, PICTORIALA drawing show-
ing each component in its actual shape according
to the manufacturers installation.
DIAGRAM, SCHEMATIC(See Diagram,
DIAPHRAGMA dividing membrane or
DIFFUSERA duct of varying cross section
designed to convert a high-speed gas flow into
low-speed at an increased pressure.
DISPLACEMENTThe volume of fluid that
can pass through a pump, motor, or cylinder in
a single revolution or stroke.
DIVERGENTMoving away from each
other, as the inner wall of a tube that flares
EFFICIENCYThe ratio of the output
power to the input power, generally expressed as
ENERGYThe ability or capacity to do
EQUILIBRIUMA state of balance between
opposing forces or actions.
FAHRENHEITThe temperature scale using
the freezing point of water as 32 and the boiling
point as 212, with 180 equal divisions between,
FEEDBACKA transfer of energy from the
output of a device to its input.
FILTERA device whose primary function
is the retention by a porous media of insoluble
contaminants from a fluid.
FILTER ELEMENTThe porous device that
performs the actual process of filtration.
FILTER MEDIAThe porous materials that
perform the actual process of filtration.
FILTER MEDIA, SURFACEPorous
materials that primarily retain contaminants on
the influent face.
FLASH POINTThe temperature to which
a liquid must be heated under specified conditions
of the test method to give off sufficient vapor to
form a mixture with air that can be ignited
momentarily by a specified flame.
FLOW, LAMINARA flow situation in
which fluid moves in parallel layers (also referred
to as streamline flow).
FLOW, METEREDFlow at a controlled
FLOW, TURBULENTA flow situation in
which the fluid particles move in a random
FLOW RATEThe volume, mass, or weight
of a fluid passing through any conductor per unit
FLOWMETERAn instrument used to
measure quantity or the flow rate of a fluid
FLUIDA liquid or a gas.
FLUID FLOWThe stream or movement of
a fluid, or the rate of its movement.
FLUID FRICTIONFriction due to the
viscosity of fluids.
FLUID, FIRE-RESISTANTA fluid
difficult to ignite, which shows little tendency to