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Fabrication integrity point -- the differential gas pressure at which the first
stream of gas bubbles are emitted from a wetted filter element under standard
test conditions.
False brinelling -- false brinelling of needle roller bearings is actually
a fretting corrosion of the surface since the rollers are the I.D. of the bearing.
Although its appearance is similar to that of brinelling, false brinelling is
characterized by attrition of the steel, and the load on the bearing is less
than that required to produce the resulting impression. It is the result of
a combination of mechanical and chemical action that is not completely understood,
and occurs when a small relative motion or vibration is accompanied by some
loading, in the presence of oxygen.
Fatigue chunks -- thick three-dimensional particles exceeding 50 microns indicating
severe wear of gear teeth.
Fatigue platelets -- normal particles between 20 and 40 microns found in gear
box and rolling element bearing oil samples observed by analytical ferrography.
A sudden increase in the size and quantity of these particles indicates excessive
wear.
Fatigued -- a structural failure of the filter medium due to flexing caused
by cyclic differential pressure.
Ferrography -- an analytical method of assessing machine health by quantifying
and examining ferrous wear particles suspended in the lubricant or hydraulic
fluid.
Film strength -- property of a lubricant that acts to prevent scuffing or scoring
of metal parts.
Filter -- any device or porous substance used as a strainer for cleaning fluids
by removing suspended matter.
Filter Efficiency -- method of expressing a filter's ability to trap and retain
contaminants of a given size.
Filter element -- the porous device which performs the actual process of filtration.
Filter head -- an end closure for the filter case or bowl that contains one
or more ports.
Filter housing -- a ported enclosure that directs the flow of fluid through
the filter element.
Filter life test -- a type of filter capacity test in which a clogging contaminant
is added to the influent of a filter, under specified test conditions, to produce
a given rise in pressure drop across the filter or until a specified reduction
of flow is reached. Filter life may be expressed as test time required to reach
terminal conditions at a specified contaminant addition rate.
Filter media, depth -- porous materials which primarily retain contaminants
within a tortuous path, performing the actual process of filtration.
Filter media, surface -- porous materials which primarily retain contaminants
on the influent face, performing the actual process of filtration.
Filtration (Beta) ratio -- the ratio of the number of particles greater than
a given size in the influent fluid to the number of particles greater than the
same size in the effluent fluid.
Filtration -- the physical or mechanical process of separating insoluble particulate
matter from a fluid, such as air or liquid, by passing the fluid through a filter
medium that will not allow the particulates to pass through it.
Fire point (Clevelend Open Cup) -- the temperature to which a combustible liquid
must be heated so that the released vapor will burn continuously for a minimum of 5 seconds when ignited
under specified conditions.
Fire-resistant fluid -- lubricant used especially in high-temperature or hazardous
hydraulic applications. Three common types of fire-resistant fluids are: (1)
water-petroleum oil emulsions, in which the water prevents burning of the petroleum
constituent; (2) water-glycol fluids; and (3) non-aqueous fluids of low volatility,
such as phosphate esters, silicones, and halogenated hydrocarbon-type fluids.
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