Lubricants Glossary 1 Flashcards
All the common terms used in the Lubricants Industry (36 cards)
Abrasion
A general wearing away of a surface by constant scratching, usually due to the presence of foreign matter such as dirt, grit, or metallic particles in the lubricant. It may also cause a break down of the material (such as the tooth surfaces of gears). Lack of proper lubrication may result in abrasion.
Abrasive Wear
(Or cutting wear) Comes about when hard surface asperities or hard particles that have embedded themselves into a soft surface and plough grooves into the opposing harder surface, e.g., a journal.
Absolute Filtration Rating
The diameter of the largest hard spherical particle that will pass through a filter under specified test conditions. This is an indication of the largest opening in the filter elements.
Absolute Pressure
The sum of atmospheric and gage pressure
Absolute Viscosity
A term used interchangeably with viscosity to distinguish it from either kinematic viscosity or commercial viscosity. Absolute viscosity is the ratio of shear stress to shear rate. It is a fluid’s internal resistance to flow. The common unit of absolute viscosity is the poise. Absolute viscosity divided by fluid density equals kinematic viscosity. It is occasionally referred to as dynamic viscosity. Absolute viscosity and kinematic viscosity are expressed in fundamental units. Commercial viscosity such as Saybolt viscosity is expressed in arbitrary units of time, usually seconds.
Absorbent Filter
A filter medium that holds contaminant by mechanical means
Absorption
The assimilation of one material into another; in petroleum refining, the use of an absorptive liquid to selectively remove components from a process stream.
AC Fine Test Dust (ACFTD)
A test contaminant used to assess both filters and the contaminant sensitivity of all types of tribological mechanisms.
Accumulator
A container in which fluid is stored under pressure as a source of fluid power.
Acid
In a restricted sense, any substance containing hydrogen in combination with a nonmetal or nonmetallic radical and capable of producing hydrogen ions in solution.
Acid Number
The quantity of base, expressed in milligrams of potassium hydroxide, that is required to neutralize the acidic constituents in 1 g of sample.
Acid Sludge
The residue left after treating petroleum oil with sulfuric acid for the removal of impurities. It is a black, viscous substance containing the spent acid and impurities.
Acid Treating
A refining process in which unfinished petroleum products, such as gasoline, kerosene, and lubricating oil stocks, are contacted with sulfuric acid to improve their color, odor, and other properties
Acidity
In lubricants, acidity denotes the presence of acid-type constituents whose concentration is usually defined in terms of total acid number. The constituents vary in nature and may or may not markedly influence the behavior of the lubricant.
Activated Alumina
A highly porous material produced from dehydroxylated aluminium hydroxide. Is used as a desiccant and as a filtering medium.
Actuator
A device used to convert fluid energy into mechanical motion.
Additive
A chemical substance added to a petroleum product to impart or improve certain properties. Common petroleum product additives are: antifoam agent, anti-wear additive, corrosion inhibitor, demulsifier, detergent, dispersant, emulsifier, EP additive, oiliness agent, oxidation inhibitor, pour point depressant, rust inhibitor, tackiness agent, viscosity index (VI.) improver.
Additive Level
The total percentage of all additives in an oil. (Expressed in % of mass (weight) or % of volume)
Additive stability
The ability of additives in the fluid to resist changes in their performance during storage or use.
Adhesion
The property of a lubricant that causes it to cling or adhere to a solid surface.
Adhesive Wear
Is often referred to as galling, scuffing, scoring, or seizing. It happens when sliding surfaces contact one another, causing fragments to be pulled from one surface and to adhere to the other.
Adsorbent Filter
A filter medium primarily intended to hold soluble and insoluble contaminants on its surface by molecular adhesion.
Adsorption
Adhesion of the molecules of gases, liquids, or dissolved substances to a solid surface, resulting in relatively high concentration of the molecules at the place of contact; e.g. the plating out of an anti-wear additive on metal surfaces.
Adsorptive Filtration
The attraction to, and retention of particles in, a filter medium by electrostatic forces, or by molecular attraction between the particles and the medium.
