GLOSSARY OF TERMS
The following definitions apply to terms used in this bulletin:
ACIDITY-A sour condition of the coolant. This condition accelerates corrosion of iron and other metals.
ALKALINITY-A bitter condition of the coolant. This condition accelerates corrosion of non-ferrous metals.
AMBIENT TEMPERATURE-The atmospheric temperature of the immediate surrounding area.
ANODES-Active metals such as zinc and magnesium which, when attached to steel or other metal in a water
environment, prevent the corrosion of the metal. The anodes corrode and are sacrificed instead of the steel.
ANTIFREEZE-A solution which, when mixed with water, lowers the freezing point.
ANTlFREEZE EXTENDER-A solution containing buffering agents and corrosion inhibitors for use in reinhibiting used
MILA-46153 antifreeze or inhibiting water.
BORAX (SODIUM BORATE)-A chemical used to impart a condition of low alkalinity to a water solution.
BUFFERING AGENT-A chemical which stabilizes (neutralizes) the acid and bases in water.
CAPILLARY SPACES-Extremely small pores which are formed under rust and scale.
CARBONIC ACID-A mild acid which is formed when carbon dioxide gas dissolves in water.
CAVITATION-A form of corrosion resulting in the formation of deep and shallow cavities. Cavities formed by cavitation
are larger than those formed by pitting.
CHEMICAL TREATMENT-The process of adding correct portions of proper chemicals to cooling water in order to inhibit
corrosion and the formation of scale.
CHROMATES-A class of salts derived from chromic acid. Sodium potassium chromates and dichromates are widely
used in water treatment because they are very soluble and react with metal surfaces to form a surface relatively immune
CONCENTRATION-The weight of a specific material per unit volume of coolant.
CONDITIONING CHEMICALS-The remedial chemicals added to untreated fresh water to neutralize the harmful effects
of the corrosive environment and the scale-forming elements.
COOLANT-The circulating element, generally fresh water, which carries away the heat generated by the friction of
moving parts of an engine.
COOLING SYSTEM-The structural parts of an engine through which the coolant circulates.
COOLING WATER-The chemically treated water (coolant) circulating in an engine.
CORROSION INHIBITORS-Chemical agents which prevent (inhibit) corrosion.
CORROSIVE ENVIRONMENT-The corrosive gases and liquids bathing a metal surface.
DECANT-The process of allowing a dispersed solid material to settle out of a liquid and then carefully pouring off the
DISSIMILAR METAL-Different metals coupled together, in a water environment, constitute a galvanic couple which is
destructive to one of the metals; an example, zinc anodes slabs coupled to a steel surface of brass fitting coupled to
DISSOLVE-The process of reducing a solid to a liquid solution.
DISSOLVED OXYGEN-Oxygen dissolved in water. The concentration of dissolved oxygen in water is greater than in air.