WHAT WE DO

Glossary of Terms

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.

Face seal: a device that prevents leakage of fluids along rotating shafts. Sealing is accomplished by a stationary primary seal ring bearing against the face of a mating ring mounted on a shaft. Axial pressure maintains the contact between the seal ring and the mating ring.

Fat: An animal or vegetable oil which will combine with an alkali to saponify and form a soap.


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.

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: 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.

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.

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.)
Floc Point : The temperature at which wax or solids separate in an oil
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.

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.

Flowmeter: a device which indicates either flow rate, total flow, or a combination of both.

Fluid: a general classification including liquids and gases.

Fluid compatibility: the suitability of filtration medium and seal materials for service with the fluid involved.

Fluid opacity: related to the ability of a fluid to pass light.

Fluid power: energy transmitted and controlled through use of a pressurized fluid.

Fluid, fire resistant: a fluid difficult to ignite which shows little tendency to propagate flame.

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.

Foam inhibitor : A substance introduced in a very small proportion to a lubricant or a coolant to prevent the formation of foam due to aeration of the liquid, and to accelerate the dissipation of any foam that may form

Foaming: A frothy mixture of air and a petroleum product (e.g., lubricant, fuel oil) that can reduce the effectiveness of the product, and cause sluggish hydraulic operation, air binding of oil pumps, and overflow of tanks or sumps. Foaming can result from excessive agitation, improper fluid levels, air leaks, cavitation, or contamination with water or other foreign materials. Foaming can be inhibited with an antifoam agent. The foaming characteristics of a lubricating oil can be determined by blowing air through a sample at a specified temperature and measuring the volume of foam, as described in test method ASTM D 892.

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 the Four-Ball EP 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.

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 continuous 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
Gage: an instrument or device for measuring, indicating or comparing a physical characteristic.

Foaming: A frothy mixture of air and a petroleum product (e.g., lubricant, fuel oil) that can reduce the effectiveness of the product, and cause sluggish hydraulic operation, air binding of oil pumps, and overflow of tanks or sumps. Foaming can result from excessive agitation, improper fluid levels, air leaks, cavitation, or contamination with water or other foreign materials. Foaming can be inhibited with an antifoam agent. The foaming characteristics of a lubricating oil can be determined by blowing air through a sample at a specified temperature and measuring the volume of foam, as described in test method ASTM D 892.

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 the Four-Ball EP 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.

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 continuous 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
Gage: an instrument or device for measuring, indicating or comparing a physical characteristic.