ASTM D4725-98

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Designation: D 4725 – 98
Standard Terminology for
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Engine Coolants
This standard is issued under the fixed designation D 4725; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
antifoam, n—a substance added to engine coolant concentrate, the radiator, consisting of water plus a corrosion inhibitor
corrosion inhibitor packages, or supplemental coolant addi- package, or a blend of water and glycol engine coolant
tives to prevent or suppress foam. concentrate.
DISCUSSION—Eliminating foam improves heat transfer. DISCUSSION—Engine coolants may also contain supplemental coolant
additives.
antifreeze, n—a term frequently used in the marketplace for
engine coolant concentrate, n—a formulated liquid product
engine coolant concentrate. (See engine coolant concen-
intended to be diluted with water for use in engine cooling
trate.)
systems.
ash content, n—the residue from an engine coolant concen-
trate, antirust, or engine coolant that remains after evapora-
DISCUSSION—Functionally, the product provides a lower freeze point
tion, charring, and ignition at strong heat.
and mitigates corrosion and foaming.
boiling point, n—the temperature at which the vapor pressure
engine dynamometer test, n—a laboratory full-scale engine
of an engine coolant reaches atmospheric pressure under
test designed to evaluate corrosion protection and inhibitor
equilibrium boiling conditions.
stability of engine coolants under simulated operational
cavitation corrosion, n—a form of localized, accelerated
conditions.
corrosion characterized by deep pitting and caused by high
erosion corrosion, n—nonuniform, accelerated corrosion
mechanical forces resulting from coolant vapor bubble
characterized by a smooth appearance and caused by high-
collapse at the surface of the metal.
velocity coolant.
cavitation erosion corrosion, n—the mechanical removal of
protective films on metal by the formation and collapse of
DISCUSSION—The corrosive attack may be aggravated by suspended
solids.
vapor bubbles in a liquid,and the abrasive action of a liquid,
which may contain suspended solids, moving at high veloc-
extended life coolant, n—an engine coolant for light-duty
ity.
service vehicles with recommended change-out of the cool-
DISCUSSION—The mechanical removal of the protective films exposes ant after 160 000 km (100 000 miles), 5 years, or 4000
fresh metal to corrosive attack.
operating hours.
foaming tendencies, n—a laboratory test conducted in glass-
coolant additive package, n—the combination of inhibitors
ware to evaluate the tendency of an engine coolant to foam
added to an engine coolant to mitigate cooling system
under standard conditions of aeration and temperature.
degradation, corrosion, scaling, and foaming, or to provide
freezing point, n—the temperature at which ice crystals begin
other desirable properties.
to form in an engine coolant when tested in accordance with
corrosion inhibitor package, n—the combination of inhibi-
Test Method D 1177 for Freezing Point of Aqueous Engine
tors added to an engine coolant to mitigate cooling system
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Coolant Solution.
corrosion.
glassware corrosion test, n—a laboratory screening test for
corrosive water, n—a standard solution containing 100 ppm
evaluating the corrosion protection properties of engine
each of sulfate, chloride, and bicarbonate ions introduced as
coolants on metal test specimens under controlled conditions
the sodium salts to distilled water.
of aeration and temperature.
dye, n—a colorant added to an engine coolant to give it a
glycol engine coolant concentrate, n— an engine coolant
distinctive color.
concentrate in which the freeze point depressant is ethylene
engine coolant, n—a heat exchange fluid designed to transfer
or propylene glycol, with inhibitors to minimize foaming
heat from the engine block and accessories to the air through
and corrosion.
DISCUSSION—Small amounts of other glycols may be present.
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This terminology is under the jurisdiction of ASTM Committee D-15 on Engine
Coolants and is the direct responsibility of Subcommittee D15.92 on Terminology.
Current edition approved June 10, 1998. Published March 1999. Originally
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published as D 4725 – 87. Last previous edition D 4725 – 97. Annual Book of ASTM Standards, Vol 15.05.
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D 4725
DISCUSSION—The prediluted coolant is intended for direct addition to
heavy-duty, adj— in internal combustion engine operation,
an engine cooling system.
characterized b
...