ASTM G89-85
(Test Method)Methods for Cathodic Disbonding of Pipeline Coatings Subjected to Cyclic Temperatures (Withdrawn 1992)
Methods for Cathodic Disbonding of Pipeline Coatings Subjected to Cyclic Temperatures (Withdrawn 1992)
General Information
Standards Content (Sample)
ASTM G87 85 m 0757530 0055527 7 m
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AMERICAN SOCIETY FOR TESTINO ANO MATERPALS
1916 Raa St., Phikdrlphia, PI. 19103
Rlprinted from thr Annual Book of ASTM St~dard8, Copyright ASTM
If not lind In th amont combinai induc, will vr in th. Mxt oclition.
Standard Methods for
- .
CATHODIC DISBONDING OF 'PIPELINE COATINGS
SUBJECTED TO CYCLIC TEMPERATURES'
This standard is issued under the fixed designation G 89: the number immcdiitely following the designation indicates the year of
original adoption or, in the case of revision, the year of iast revision. A number in parentheses indicates the year of last mpproval.
A supencript epsilon (e) indicates an editorial change since the kit revision or reapproval.
1. %9pc
men to the negative terminal of a source of direct
current and by connecting an anode to the posi-
1.1 This method covers an accelerated proce-
tive terminal. Electrical instrumentation is pro-
dure for determining comparative characteristics
vided for measuring the current flowing in the
of insulating coating systems applied to steel pipe
cell. The electrical ptential is also measured and
exterior for the purpose of preventing or mitigat-
the specimen is physically examined at intervals
ing corrosion that may occur in underground
during the test period and upon conclusion of
will be exposed to high
service where the pipe
the test.
temperatures, and is under cathodic protection.
3. I, I The test is conducted under cycling con-
This method is intended for use with samples of
ditions alternating between cathodic stress at an
coated pipe taken from commercial production
elevated temperature and static conditions (no
and is applicable to such samples when the coat-
cathodic stress) at a depressed temperature.
ing is characterized by function as an electrical
bamer.
4. Significance and Use
1.2 The values stated in SI units to three Sig-
4.1 Breaks or holidays in pipe coatings may
nificant decimals are to be regarded as the stand-
expose the pipe to possible corrosion, since after
ard.
a pipe has been installed underground, the sur-
1.3 This siandard may involve hazardous ma-
rounding earth could be an effective electrolyte.
rerials, operaiions, and equipmeni. This standard
Damage to pipe coating is almost unavoidable
does no[ pitrpori io address all ofihe safity prob-
during transportation and construction. Normal
lems associaied with its me. It is the responsibil-
soil potentials may cause apparent loosening of
ity of whoever uses [his standard (o consult and
the coating, beginning at holiday edges, in some
establish appropriaie safety and healih praciices
cases increasing the apparent size of the holiday.
and deiermine [he applicabiliiy of regulalory limi-
Holidays may also caused by such potentials.
[aiions prior io use.
Buried piplines are alsu sûmeihes subjected
2. Applicable Document to higher or lower than ambient temperatures.
Compressors increase the temperature of the gas
2.1 ÀSTM Siandard:
and cause an increase in the temperature of the
G 12 Method for Nondestructive Measure-
pipeline. Pipelines buried in close proximity to
of Pipeline Coatings
ment of Film Thickness
steam lines are subjected to elevated tempera-
on Steel2
tures. Reduction of gas pressure at regulators
3. Summary of Method
' Thcsc methods arc undcr the jurisdictioii of ASTM Com-
3.1 This method subjects the coating on the
G-3 on Durability of Nonmetallic Materials and are the
mittee
test specimen to electrical stress in a highly con-
direct responsibility of Subcommittee G03.06 on Durability of
Pipeline Coatings and Linings.
ductive electrolyte. The coating is artificially per-
Current edition approved Jan. 25, 1985. Published March
forated before starting the test. The electrical
1985.
stress is produced by connecting the test speci- 'Annual Book of ASTM Standards, Vol 14.02.
---------------------- Page: 1 ----------------------
ASTM G89 85 0759530 0055528 9
G 89
causes a’decrease in pipeline temperature. Pipe
shall be used, capable of withstanding internal
heating at not less than 60% and suitable for
in storage may be subjected to higher and lower
temperature cycling than underground. Severe continuous circulation of the electrolyte. A 19-L
temperature cycling conditions are also found in (5-gal) cylindrical glass vessel has been found
hot and cold climates, particularly during periods suitable, having an approximate diameter of 300
mm (12 in.) and a depth of 300 mm. A flat
of start-up and shutdown. While apparently
bottom is required for operation of a magnetic
loosened coating and cathodic holidays may not
stimng rod. Dimensions of the vessel shall permit
result in corrosion, this test provides accelerated
the following requirements:
conditions for lbsening to occur and therefore,
5. i. 1 Test specimens shall be suspended ver-
gives a measure of resistance of coatings to this
type of action. tically in the vessel
...
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