FABRIC: A collective term applied to cloth no matter how constructed and regardless of the kind of fiber used.
FAHRENHEIT: A thermometric scalre in which water boils at 212° and freezes at 32°. °F = (1.8 x °C) + 32°
FAN: A power-driven machine that moves a continuous volume of air by converting rotational mechanical energy to an increase in the total pressure of the moving air.
FAN CAPACITY: Performance requirement for which a fan is selected to meet specific system calculations given in terms of ACFM at the fan inlet.
FAN CLASS: Operating limits at which a fan must be physically capable of operating safely.
FAN LAWS: Theoretical constant relationships between CFM, RPM and BHP for a given fan used in a given fixed system: CFM varies as RPM SP varies as (RPM)2 BHP varies as (RPM)3
FC: Fan wheel design using forward-curved blades.
FEDERAL IMPLEMENTATION PLAN (FIP): Under current law, a lederally implemented plan to achieve attainment of an air quality standard, used when a state is unable to develop an adequate plan. Under the Senate bill, a plan containing control measures developed and promulgated by EPA in order to fill gaps in a State Implementation Plan (SIP).
FELTED FABRIC: Type bag used on most pulse jet dust collectors. Features a heavy, thick cloth of short fibers on a woven backing.
FIBER: The fundamental unit comprising a textile raw material such as cotton, wool, etc.
FILAMENT-MONO: One continuous strand of fiber to indefinite length.
FILAMENT-MULTI: More than one mono-filament strand grouped together of definite length.
FILL: Crosswise threads woven by loom.
FILL COUNT: Number of threads per inch of cloth.
FILTER AREA: Quantity of filter media available for collection of contaminants. Expressed in square feet.
FILTER CAKE: The accumulation of dust on a bag before cleaning. This cake assists in the filtering of dust.
FILTER COLLECTOR: A mechanical filtration system for removing particulate matter from a gas stream for measurement, analysis or control. Also called bag collector. Filters are designed in a variety of sizes and materials for specific purposes. Also called bag collector or cartridge.
FINES: Fine particulate; aerosol.
FIRE RETARDANT: A special treatment that results in the filter media not supporting combustion unless a flame source is present.
FLASHING: Sheet metal strip placed at the junction of intersecting exterior building surfaces to make the joint water-tight.
FLEXING: Bending, or contracting and expanding.
FLY ASH: The particulate impurities resulting from burning coal or other material.
FOG: The condensation of water vapor in air. Also see Smog.
FOOT-POUND (ft.-lb.): Torque rating or requirement; equivalent to the force required to move a one-pound weight one foot in distance, equal to 12 in.-lb.
FORCED DRAFT: How air is provided in a process such as a combustion process, when air is blown or forced into a process. Known as a “forced draft” system. Also see Induced Draft.
FORCED DRAFT BURNER: A burner that has its secondary air supplied under pressure. This is normally done by surrounding the dryer opening with a plenum or windbox and supplying the air with a low-pressure fan.
FOSSIL FUELS: Coal, oil and natural gas; so-called because they are the remains of ancient plant and animal life.
FPM (Feet per minute): Commonly defines air velocity (to determine velocity pressure or suitability for material conveying), shaft-bearing speeds (used to determine lubrication requirements) and wheel tip speeds.
FRAME SIZE: A set of physical dimensions of motors established by National Electrical Manufacturers Association (NEMA) for interchangeability between manufacturers. Dimensions include: shaft diameter, shaft height and motor mounting footprint.
FREQUENCY: Any cyclic event, whether vibration, alternating current or rotational speed. Usually expressed in cycles per second (cps) or cycles.
FRICTION LOSS: Resistance to air flow through any duct or fitting, given in terms of static pressure.
FRP: Abbreviation for fiberglass-reinforced-plastic.
FUGITIVE EMISSIONS: Emissions not caught by a capture system.
FULL-LOAD SPEED: The speed at which the rated horsepower is developed. This speed is less than synchronous speed and varies with the motor type and manufacturer.
FULL-LOAD TORQUE: The torque required to produce the rated horsepower at fullload speed.
FUME: An aerosol consisting of dispersed liquids or solids having particles smaller than 1 micron. Fine particles dispersed in air and formed by condensation, such as heat oxidation of metals or oil smokes.
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