    | |
 |
|
|
|
|
| |
|
|
|
| |
|
|
|
| |
|
|
|
| |
|
|
|
|
|
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.) 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. Flow meter -- a device which indicates either flow rate, total flow, or a combination of both. Fluid -- a general classification including liquids and gases. Fluid analysis -- process of determining through testing wear metals and contaminants present in equipment fluids. This process can determine sources and quantities of contamination and provide valuable maintenance indicators for future planning. 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. Foaming -- a frothy mixture of air and a lubricating oil that can reduce the effectiveness of the product causing sluggish hydraulic systems, overflowing of oil tanks, and air binding of oil pumps. Foaming can develop from air leaks, cavitation, improper fluid levels, poor sump design, excessive agitation and contamination. Foam inhibitor -- see Anti-foam additive. Force feed lubrication -- a system of lubrication in which the lubricant is supplied to the bearing surface under pressure. Four ball test -- an apparatus used to evaluate the anti-wear and extreme pressure properties of a lubricating oil or grease. In both tests three steel balls are clamped together to form a cradle upon which a forth ball rotates on the vertical axis. In the anti-wear test the rotating ball is applied at a specific speed, temperature, load. At the end of a specified time the three stationary balls are removed and the scar diameters are measured with the average being reported. For the extreme pressure test, the rotating ball is applied at higher and higher loads until the rotating ball seizes and welds to the stationary balls. Typically the Weld Point and Load Wear Index is reported. Fretting -- a form or wear resulting from small-amplitude oscillations or vibrations between two closely fit surfaces (i.e. bearing race to shaft or housing). With ferrous metals the wear particles oxidize to a reddish iron oxide with the appearance of rust or corrosion. 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. FTIR = Fourier Transform Infrared Spectroscopy -- An instrument where the amount of infrared light that is absorbed or transmitted through an oil sample is used to determine levels of soot, oxidation, nitration and sulphation. Other contaminants such as water, fuel, glycol as well as additive depletion may be evaluated with the FT-IR instrument. Proper determination of some of these contaminants requires a specific new oil reference. Fuller’s Earth -- a naturally occurring sedimentary clay composed mainly of alumina, silica, iron oxides, lime, magnesia, and water, in extremely variable proportions. It possesses an effective ability to remove oil from surfaces. Fuller's earth can often be found as a contaminant during oil analysis and originates from such sources as floor sweeping compounds and filtration media for acid control in some turbine applications. 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 -- or hydrodynamic -- wedge. FZG Test -- Forchungstelle fur Zahnrader und Getriebau. A test used to evaluate the load carrying capacities, wear characteristics and shear stability of gear oils. The test gear set is run in the lubricant at gradually increased load stages until failure.
|
