ASTM G62-07(2013)
(Test Method)Standard Test Methods for Holiday Detection in Pipeline Coatings
Standard Test Methods for Holiday Detection in Pipeline Coatings
SIGNIFICANCE AND USE
5.1 Method A—Method A describes a quick, safe method for determining if pinholes, voids, or metal particles are protruding through the coating. This method will not, however, find any thin spots in the coating. This method will determine the existence of any gross faults in thin-film pipeline coatings.
5.2 Method B—Method B describes a method for determining if pinholes, voids, or metal particles are protruding through the coating, and thin spots in pipeline coatings. This method can be used to verify minimum coating thicknesses as well as voids in quality-control applications.
SCOPE
1.1 These test methods cover the apparatus and procedure for detecting holidays in pipeline type coatings.
1.2 Method A is designed to detect holidays such as pinholes and voids in thin-film coatings from 0.0254 to 0.254 mm (1 to 10 mils) in thickness using ordinary tap water and an applied voltage of less than 100 V d-c. It is effective on films up to 0.508 mm (20 mils) thickness if a wetting agent is used with the water. It should be noted, however, that this method will not detect thin spots in the coating, even those as thin as 0.635 mm (25 mils). This may be considered to be a nondestructive test because of the relatively low voltage.
1.3 Method B is designed to detect holidays such as pinholes and voids in pipeline coatings; but because of the higher applied voltages, it can also be used to detect thin spots in the coating. This method can be used on any thickness of pipeline coating and utilizes applied voltages between 900 and 20 000 V d-c.2 This method is considered destructive because the high voltages involved generally destroy the coating at thin spots.
1.4 The values stated in SI units to three significant decimals are to be regarded as the standard. The values given in parentheses are for information only.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: G62 − 07(Reapproved 2013)
Standard Test Methods for
Holiday Detection in Pipeline Coatings
ThisstandardisissuedunderthefixeddesignationG62;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 These test methods cover the apparatus and procedure
A742/A742M Specification for Steel Sheet, Metallic Coated
for detecting holidays in pipeline type coatings.
and Polymer Precoated for Corrugated Steel Pipe
1.2 Method A is designed to detect holidays such as pin-
holes and voids in thin-film coatings from 0.0254 to 0.254 mm 3. Terminology
(1 to 10 mils) in thickness using ordinary tap water and an
3.1 Definitions:
applied voltage of less than 100 V d-c. It is effective on films
3.1.1 holiday, n—smallfaultsorpinholesthatpermitcurrent
up to 0.508 mm (20 mils) thickness if a wetting agent is used
drainagethroughprotectivecoatingsonsteelpipeorpolymeric
with the water. It should be noted, however, that this method
precoated corrugated steel pipe.
will not detect thin spots in the coating, even those as thin as
3.1.2 mil, n—0.001 in.
0.635 mm (25 mils). This may be considered to be a nonde-
3.2 Definitions of Terms Specific to This Standard:
structive test because of the relatively low voltage.
3.2.1 holiday detector, n—a highly sensitive electrical de-
1.3 Method B is designed to detect holidays such as
vice designed to locate holidays such as pinholes, voids, and
pinholes and voids in pipeline coatings; but because of the
thin spots in the coating, not easily seen by the naked eye.
higher applied voltages, it can also be used to detect thin spots
These are used on the coatings of relatively high-electrical
in the coating. This method can be used on any thickness of
resistance when such coatings are applied to the surface of
pipeline coating and utilizes applied voltages between 900 and
materials of low-electrical resistance, such as steel pipe.
20 000 V d-c. This method is considered destructive because
3.2.2 pipeline type coating, n—coatings of relatively high-
the high voltages involved generally destroy the coating at thin
electrical resistance applied to surfaces of relatively low-
spots.
electrical resistance, such as steel pipe.
1.4 The values stated in SI units to three significant deci-
4. Summary of Test Methods
mals are to be regarded as the standard. The values given in
parentheses are for information only.
4.1 Both methods rely on electrical contact being made
through the pipeline coating because of a holiday or a
1.5 This standard does not purport to address all of the
low-resistance path created by metal particles, or thin spots in
safety concerns, if any, associated with its use. It is the
the coating. This electrical contact will activate an alarm
responsibility of the user of this standard to establish appro-
alerting the operator of the incidence of a holiday.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
4.2 In Method A, the applied voltage is 100 V d-c or less.
4.3 In Method B, the applied voltage is 900 to 20 000
V d-c.
These test methods are under the jurisdiction of ASTM Committee D01 on
5. Significance and Use
Paint and Related Coatings, Materials, and Applications and are the direct
responsibility of Subcommittee D01.48 on Durability of Pipeline Coating and
5.1 MethodA—MethodAdescribesaquick,safemethodfor
Linings.
determiningifpinholes,voids,ormetalparticlesareprotruding
Current edition approved June 1, 2013. Published June 2013. Originally
approved in 1979. Last previous edition approved in 2007 as G62 – 07. DOI:
10.1520/G0062-07R13. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
This was taken from the pamphlet “Operating Instructions forTinker and Rasor contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Model EP Holiday Detector.” Other manufacturers’ holiday detectors can be Standards volume information, refer to the standard’s Document Summary page on
expected to have similar voltage specifications. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G62 − 07 (2013)
through the coating. This method will not, however, find any a selected resistance, having a ⁄2 W rating, is placed across its
thin spots in the coating. This method will determine the terminals.Acommon factory setting for sensitivity is 100 000
existence of any gross faults in thin-film pipeline coatings. Ω. Most units can be reset to any predetermined sensitivity
value in this manner.
5.2 Method B—Method B describes a method for determin-
ing if pinholes, voids, or metal particles are protruding through
10. Procedure for Method A
the coating, and thin spots in pipeline coatings. This method
10.1 Use the low-voltage holiday detector described in 6.1.
can be used to verify minimum coating thicknesses as well as
voids in quality-control applications. 10.2 Assemble the wand and electrode according to the
manufacturer’s instructions and attach the ground wire to the
6. Apparatus
metal surface.
6.1 Low-Voltage Holiday Detector—A holiday detector tes-
10.3 Attach the electrode clamps to the end of the wand,
ter having an electrical energy source of less than 100 V d-c,
dampen the sponge electrode with tap water, and place it
such as a battery; an exploring electrode having a cellulose
between the clamps. Then tighten the clamps with the screw
sponge dampened with an electrically conductive liquid such
until they are well down into the sponge electrode. Attach the
as tap water; and an audio indicator to signal a defect in a
ground wire (lead with battery clamp) and the wand to the
high-electrical resistance coating on a metal substrate. A
terminals. Clip the ground wire to some point where the metal
ground wire connects the detector with the low-resistance
surface is bare. Now touch the electrode to a second point
metal surface.
where the surface is bare and note that the audible signal will
be activated. The detector is now ready to operate by passing
6.2 High-Voltage Holiday Detector—Aholiday detector tes-
ter having an electrical energy source of 900 to 20 000 V d-c; the damp sponge over the coated surface. When a holiday is
picked up by the audible alarm, the electrode can be turned on
an exploring electrode consisting of wire brush, coil-spring, or
conductive silicon electrode capable of moving along the endandtheexactspotoffailurecanbenotedbysearchingwith
pipeline coating; and an audio indicator to signal a defect in a the tip of the electrode.
high-electrical resistance coating on a metal substrate. A
10.4 The voltage between the electrode (sponge) and the
ground wire connects the detector with the low-resistance
metal surface upon which the coating lies shall not exceed 100
metal surface.
V d-c, measured between the electrode sponge and the coated
6.3 Peak or Crest Reading Voltmeter—A kilovoltmeter ca- metal when the detector is in its normal operating position.
pable of detecting a single pulse and holding it long enough for
10.5 Prior to making the inspection, ensure that the coated
the meter circuits to indicate.
surface is dry. This is particularly important if formed surfaces
are to be inspected. If the surface is in an environment where
7. Reagents and Mate
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