ASTM C1785-16
(Test Method)Standard Test Method for Concentration of Pinhole Detections in Moisture Barriers on Metal Jacketing
Standard Test Method for Concentration of Pinhole Detections in Moisture Barriers on Metal Jacketing
SIGNIFICANCE AND USE
5.1 Corrosion on the interior surface of metal jacketing can be caused by the formation of a galvanic cell between the dissimilar metals of the pipe and jacket or by crevice or pitting corrosion.
5.2 The application of a moisture barrier to the interior surface of the metal jacketing inhibits this corrosion by interfering with the galvanic cell formation or by preventing water from contacting the interior metal surface.
5.3 Holes in the moisture barrier decrease its effectiveness in preventing corrosion. Large holes, scratches, or tears in the moisture barrier visible to the naked eye are easily discerned and are cause for rejection of the metal jacketing.
5.4 Small holes called pinholes or holidays that are not visible to the naked eye but are large enough to allow corrosion are a significant concern and should be avoided to the extent possible.
5.5 This test method is used to quantify the concentration of pinhole detections present in a moisture barrier for the purpose of quality control on metal jacketing with an applied moisture barrier.
5.6 Examples of standards which have specific requirements for the maximum allowable concentration of pinhole detections in the moisture barrier are Specifications C1729 and C1767.
SCOPE
1.1 This test method covers the determination of the concentration of pinhole detections in a moisture barrier film or coating that is applied to the interior surface of metal jacketing.
1.2 Since this method relies on the completion through the metal jacketing of an electrical circuit, this method is only applicable to jacketing that is electrically conductive and has a moisture barrier applied which is not electrically conductive.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.4 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: C1785 − 16
StandardTest Method for
Concentration of Pinhole Detections in Moisture Barriers on
1
Metal Jacketing
This standard is issued under the fixed designation C1785; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2.1 continuous pinhole detection—while the test is being
conducted, a continuous sounding of the audible test equip-
1.1 This test method covers the determination of the con-
ment alarm over an area larger than the contact area of the
centration of pinhole detections in a moisture barrier film or
cellulose sponge.
coating that is applied to the interior surface of metal jacketing.
3.2.1.1 Discussion—In some cases, large portions of one or
1.2 Since this method relies on the completion through the
more of the test areas (see 8.2.1) or even all of one or more test
metal jacketing of an electrical circuit, this method is only
areas will yield a continuous pinhole detection.This concept of
applicable to jacketing that is electrically conductive and has a
a continuous pinhole detection and the area yielding this
moisture barrier applied which is not electrically conductive.
performance is necessary to quantify the number of pinhole
detections in a sample exhibiting this phenomenon (see 9.2 and
1.3 The values stated in inch-pound units are to be regarded
9.3)
as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only
3.2.2 moisture barrier (moisture retarder)—a layer of plas-
and are not considered standard.
tic film or other material applied to the inner side of metal
1.4 This standard does not purport to address all of the jacketing to inhibit jacket corrosion by interfering with the
safety concerns, if any, associated with its use. It is the
formation of a galvanic cell between the dissimilar metals of
responsibility of the user of this standard to establish appro-
the pipe and jacket or by preventing crevice or pitting
priate safety and health practices and determine the applica-
corrosion.
bility of regulatory limitations prior to use.
3.2.3 pinhole—a hole completely through a moisture barrier
typically too small to be seen by the eye.
2. Referenced Documents
3.2.4 pinhole detection—a single sounding of the audible
2
2.1 ASTM Standards:
test equipment alarm while the test is being conducted.
C168 Terminology Relating to Thermal Insulation
3.2.4.1 Discussion—Because pinholes are very small and
C1729 Specification for Aluminum Jacketing for Insulation
the dampened cellulose sponge contacts the moisture barrier in
C1767 Specification for Stainless Steel Jacketing for Insula-
an area larger than a single pinhole (see 6.4), it is theoretically
tion
possible that multiple pinholes in close proximity to each other
would register as a single detection. For this reason, this test
3. Terminology
methodmeasurestheconcentrationofpinholedetectionsrather
3.1 Definitions—Definitions in Terminology C168 apply to
than pinholes.
terms used in this specification.
3.2.5 holiday—synonymous with pinhole.
3.2 Definitions of Terms Specific to This Standard:
4. Summary of Test Method
1 4.1 A voltage is applied across the nonconductive moisture
This test method is under the jurisdiction ofASTM Committee C16 on Thermal
Insulation and is the direct responsibility of Subcommittee C16.33 on Insulation
barrier on metal jacketing using an electrode consisting of a
Finishes and Moisture.
cellulose sponge dampened with an electrically conductive
Current edition approved March 1, 2016. Published March 2016. Originally
liquid such as tap water. Holes in the moisture barrier lead to
approved in 2013. Last previous edition approved in 2015 as C1785 – 15. DOI:
10.1520/C1785-16.
completion of an electrical circuit which triggers an audible
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
alarm in the test equipment. The number of pinhole detections
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
collectively in ten specified test areas is determined and
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. reported.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
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C1785 − 16
5. Significance and Use 8. Procedure
5.1 Corrosion on the interior surface of metal jacketing can 8.1 Sample Preparation:
8.1.1 Place specimen(s) on a reasonably flat, level, and
be caused by the formation of a galvanic cell between the
dissimilar metals of
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C1785 − 15 C1785 − 16
Standard Test Method for
Concentration of Pinhole Detections in Moisture Barriers on
1
Metal Jacketing
This standard is issued under the fixed designation C1785; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the determination of the concentration of pinhole detections in a moisture barrier film or coating
that is applied to the interior surface of metal jacketing.
1.2 Since this method relies on the completion through the metal jacketing of an electrical circuit, this method is only applicable
to jacketing that is electrically conductive and has a moisture barrier applied which is not electrically conductive.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.4 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.
2. Referenced Documents
2
2.1 ASTM Standards:
C168 Terminology Relating to Thermal Insulation
C1729 Specification for Aluminum Jacketing for Insulation
C1767 Specification for Stainless Steel Jacketing for Insulation
3. Terminology
3.1 Definitions—Definitions in Terminology C168 apply to terms used in this specification.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 continuous pinhole detection—while the test is being conducted, a continuous sounding of the audible test equipment
alarm over an area larger than the contact area of the cellulose sponge.
1
This test method is under the jurisdiction of ASTM Committee C16 on Thermal Insulation and is the direct responsibility of Subcommittee C16.33 on Insulation Finishes
and Moisture.
Current edition approved Nov. 1, 2015March 1, 2016. Published November 2015March 2016. Originally approved in 2013. Last previous edition approved in 20132015
as C1785C1785 – 15.-13. DOI: 10.1520/C1785-15.10.1520/C1785-16.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3.2.1.1 Discussion—
In some cases, large portions of one or more of the test areas (see 8.2.1) or even all of one or more test areas will yield a continuous
pinhole detection. This concept of a continuous pinhole detection and the area yielding this performance is necessary to quantify
the number of pinhole detections in a sample exhibiting this phenomenon (see 9.2 and 9.3)
3.2.2 moisture barrier (moisture retarder)—a layer of plastic film or other material applied to the inner side of metal jacketing
to inhibit jacket corrosion by interfering with the formation of a galvanic cell between the dissimilar metals of the pipe and jacket
or by preventing crevice or pitting corrosion.
3.2.3 pinhole—a hole completely through a moisture barrier typically too small to be seen by the eye.
3.2.4 pinhole detection—a single sounding of the audible test equipment alarm while the test is being conducted.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
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C1785 − 16
3.2.4.1 Discussion—
Because pinholes are very small and the dampened cellulose sponge contacts the moisture barrier in an area larger than a single
pinhole (see 6.4), it is theoretically possible that multiple pinholes in close proximity to each other would register as a single
detection. For this reason, this test method measures the concentration of pinhole detections rather than pinholes.
3.2.5 holiday—synonymous with pinhole.
4. Summary of Test Method
4.1 A voltage is applied across the nonconductive moisture barrier on metal jacketing using an electrode consisting of a cellulose
sponge dampened with an electrically conductive liquid such as tap water. Holes in the moisture barrier lead to completion of an
electrical circuit which triggers an audible alarm in the test equipment. The number o
...
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