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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.
Fat
An animal or vegetable oil which will combine with an alkali to saponify and form a soap.
FFV
Flexible-Fuel Vehicle
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.
Fiber Grease
A grease with a distinctly fibrous structure, which is noticeable when portions of the grease are pulled apart.
Filler (lubricants)
Any substance, such as talc, mica, or various powders, which may be added to a grease to make it heavier in weight or consistency, but which serves no useful function in making the grease a better lubricant. (Editor’s note: Such filler may also be added to certain lubricating oils or other lubricants.)
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 Test (COC)
(See Cleveland open-cup tester)
Fire point (Clevelend Open Cup)
The temperature to which a combustible liquid must be heated so that the released vapor will burn continuously 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.
Flash point (Cleveland Open Cup)
The temperature to which a combustible liquid must be heated to give off sufficient vapor to form momentarily a flammable mixture with air when a small flame is applied under specified conditions. (ASTM Designation D 92.)
Flash point test (Pensky-Martens closed tester)
A method of test for the determination of the flash point of liquid fuels flashing below 175°F, with the exception of fuel oils.
Flash point (Tag closed-cup tester)
A method of test for the determination of the flash point of liquid fuels flashing below 175°F, with the exception of fuel oils.
Floc point
The temperature at which wax or solids separate in an oil.
Flow, laminar
A flow situation in which fluid moves in parallel lamina or layers.
Flow, turbulent
A flow situation in which the fluid particles move in a random manner.
Flow fatigue rating
The ability of a filter element to resist a structural failure of the filter medium due to flexing caused by cyclic differential pressure.
Flow rate
The volume, mass, or weight of a fluid passing through any conductor per unit of time.
Flowmeter
A device which indicates either flow rate, total flow, or a combination of both.
Fluid
A general classification including liquids and gases.
Fluid, fire resistant
A fluid difficult to ignite which shows little tendency to propagate flame.
Fluid compatibility
The suitability of filtration medium and seal materials for service with the fluid involved.
Fluid friction
Friction due to the viscosity of fluids.
Fluid opacity
Related to the ability of a fluid to pass light.
Fluid power
Energy transmitted and controlled through use of a pressurized fluid.
Flushing
A fluid circulation process designed to remove contamination from the wetted surfaces of a fluid system.
Foam
An agglomeration of gas bubbles separated from each other by a thin liquid film which is observed as a persistent phenomenon on the surface of a liquid.
Force feed lubrication
A system of lubrication in which the lubricant is supplied to the bearing surface under pressure.
Four Ball Tester
This name is frequently used to describe either of two similar laboratory machines, the Four-Ball Wear Tester and Four-Ball Tester. These machines are used to evaluate a lubricant’s anti-wear qualities, frictional characteristics or load carrying capabilities. It derives its name from the four 1/2 inch steel balls used as test specimens. Three of the balls are held together in a cup filled with lubricant while the fourth ball is rotated against them.
Fretting
Wear phenomena taking place between two surfaces having oscillatory relative motion of small amplitude.
Fretting corrosion
Can take place when two metals are held in contact and subjected to repeated small sliding, relative motions. Other names for this type of corrosion include wear oxidation, friction oxidation, chafing, and brinelling.
Friction
The resisting force encountered at the common boundary between two bodies when, under the action of an external force, one body, moves or tends to move relative to the surface of the other.
Front-end volatily
A term applied to the volatility of the lower boiling fractions of gasoline.
Fuel Sensitivity
The response of a motor fuel to the change in engine severity between the operating conditions of the ASTM Research Method (D 908) and ASTM Motor Method (D 357); numerically equal to the difference between the Research and Motor octane numbers.
FZG Test
A German gear test for evaluating EP properties.
Full flow filter
A filter that, under specified conditions, filters all influent flow.
Full-flow filtration
A system of filtration in which the total flow of a circulating fluid system passes through a filter.
Full-fluid-film lubrication
Presence of a contin-uous lubricating film sufficient to completely separate two surfaces, as distinct from boundary lubrication. Full-fluid-film lubrication is normally hydrodynamic lubrication, whereby the oil adheres to the moving part and is drawn into the area between the sliding surfaces, where it forms a pressure – or hydrodynamic – wedge.
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