ASTM C356-22

Standard Test Method for Linear Shrinkage of Preformed High-Temperature Thermal Insulation Subjected to Soaking Heat

SIGNIFICANCE AND USE
4.1 Linear shrinkage, as used in this test method, refers to the change in linear dimensions that has occurred in test specimens after they have been subjected to soaking heat for a period of 24 h and then cooled to room temperature.  
4.2 Most insulating materials will begin to shrink at some definite temperature. Usually the amount of shrinkage increases as the temperature of exposure becomes higher. Eventually a temperature will be reached at which the shrinkage becomes excessive. With excessive shrinkage, the insulating material has definitely exceeded its useful temperature limit. When an insulating material is applied to a hot surface, the shrinkage will be greatest on the hot face. The differential shrinkage which results between the hotter and the cooler surfaces often introduces strains and may cause the insulation to warp. High shrinkage may cause excessive warpage and thereby may induce cracking, both of which are undesirable. High shrinkage may also open gaps at the insulation joints to an excessive extent rendering the application less efficient and more hazardous. In order to predict the limit of permissible shrinkage in service, the degree of linear shrinkage to be tolerated by specimens of an insulating material when subjected to soaking heat must be determined from experience.  
4.3 It is recognized that a fixed relation between linear shrinkage under soaking heat and actual shrinkage in service cannot be established for different types of insulating materials. Generally the amount of shrinkage increases with time of exposure. The amount and rate of increase varies from one material to another. In addition, the various types of materials may have different amounts of maximum permissible shrinkage. Therefore, each product must define its own specific limits of linear shrinkage under soaking heat.
SCOPE
1.1 This test method covers the determination of the amount of linear shrinkage and other changes that occur when a preformed thermal insulating material is exposed to soaking heat. This test method is limited to preformed high-temperature insulation that is applicable to hot-side temperatures in excess of 150°F (66°C), with the exception of insulating fire brick which is covered by Test Method C210.  
1.2 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.  
1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Apr-2022
• ICS: 81.080 - Refractories
• Technical Committee: C16 - Thermal Insulation
• Drafting Committee: C16.31 - Chemical and Physical Properties

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C356 − 22
Standard Test Method for
Linear Shrinkage of Preformed High-Temperature Thermal
1
Insulation Subjected to Soaking Heat
This standard is issued under the fixed designation C356; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 3. Terminology
1.1 This test method covers the determination of the amount 3.1 Definitions—Terminology C168 shall apply to the terms
of linear shrinkage and other changes that occur when a used in this test method.
preformed thermal insulating material is exposed to soaking
4. Significance and Use
heat.Thistestmethodislimitedtopreformedhigh-temperature
insulation that is applicable to hot-side temperatures in excess
4.1 Linear shrinkage, as used in this test method, refers to
of 150°F (66°C), with the exception of insulating fire brick
the change in linear dimensions that has occurred in test
which is covered by Test Method C210.
specimens after they have been subjected to soaking heat for a
period of 24 h and then cooled to room temperature.
1.2 The values stated in inch-pound units are to be regarded
as standard. The values given in parentheses are mathematical
4.2 Most insulating materials will begin to shrink at some
conversions to SI units that are provided for information only
definite temperature. Usually the amount of shrinkage in-
and are not considered standard.
creases as the temperature of exposure becomes higher. Even-
1.3 This standard does not purport to address all of the tually a temperature will be reached at which the shrinkage
safety concerns, if any, associated with its use. It is the becomes excessive. With excessive shrinkage, the insulating
responsibility of the user of this standard to establish appro- material has definitely exceeded its useful temperature limit.
priate safety, health, and environmental practices and deter- When an insulating material is applied to a hot surface, the
mine the applicability of regulatory limitations prior to use. shrinkage will be greatest on the hot face. The differential
1.4 This international standard was developed in accor- shrinkage which results between the hotter and the cooler
dance with internationally recognized principles on standard- surfaces often introduces strains and may cause the insulation
ization established in the Decision on Principles for the to warp. High shrinkage may cause excessive warpage and
Development of International Standards, Guides and Recom-
thereby may induce cracking, both of which are undesirable.
mendations issued by the World Trade Organization Technical High shrinkage may also open gaps at the insulation joints to
Barriers to Trade (TBT) Committee.
an excessive extent rendering the application less efficient and
more hazardous. In order to predict the limit of permissible
2. Referenced Documents
shrinkage in service, the degree of linear shrinkage to be
2 tolerated by specimens of an insulating material when sub-
2.1 ASTM Standards:
jected to soaking heat must be determined from experience.
C168 Terminology Relating to Thermal Insulation
C210 TestMethodforReheatChangeofInsulatingFirebrick 4.3 It is recognized that a fixed relation between linear
C411 Test Method for Hot-Surface Performance of High-
shrinkage under soaking heat and actual shrinkage in service
Temperature Thermal Insulation cannotbeestablishedfordifferenttypesofinsulatingmaterials.
Generally the amount of shrinkage increases with time of
exposure. The amount and rate of increase varies from one
material to another. In addition, the various types of materials
1
ThistestmethodisunderthejurisdictionofASTMCommitteeC16onThermal
Insulation and is the direct responsibility of Subcommittee C16.31 on Chemical and may have different amounts of maximum permissible shrink-
Physical Properties.
age.Therefore, each product must define its own specific limits
Current edition approved May 1, 2022. Published May 2022. Originally
of linear shrinkage under soaking heat.
approved in 1960. Last previous edition approved in 2017 as C356 – 17. DOI:
10.1520/C0356-22.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 5. Apparatus
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
5.1 Furnace—A gas-fired or electrically heated muffle
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. fu
...

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: C356 − 17 C356 − 22
Standard Test Method for
Linear Shrinkage of Preformed High-Temperature Thermal
1
Insulation Subjected to Soaking Heat
This standard is issued under the fixed designation C356; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 This test method covers the determination of the amount of linear shrinkage and other changes that occur when a preformed
thermal insulating material is exposed to soaking heat. This test method is limited to preformed high-temperature insulation that
is applicable to hot-side temperatures in excess of 150°F (66°C), with the exception of insulating fire brick which is covered by
Test Method C210.
1.2 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.
1.3 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
C168 Terminology Relating to Thermal Insulation
C210 Test Method for Reheat Change of Insulating Firebrick
C411 Test Method for Hot-Surface Performance of High-Temperature Thermal Insulation
3. Terminology
3.1 Definitions—Terminology C168 shall apply to the terms used in this test method.
4. Significance and Use
4.1 Linear shrinkage, as used in this test method, refers to the change in linear dimensions that has occurred in test specimens after
they have been subjected to soaking heat for a period of 24 h and then cooled to room temperature.
1
This test method is under the jurisdiction of ASTM Committee C16 on Thermal Insulation and is the direct responsibility of Subcommittee C16.31 on Chemical and
Physical Properties.
Current edition approved May 1, 2017May 1, 2022. Published June 2017May 2022. Originally approved in 1960. Last previous edition approved in 20102017 as
C356 – 10.C356 – 17. DOI: 10.1520/C0356-17.10.1520/C0356-22.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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C356 − 22
4.2 Most insulating materials will begin to shrink at some definite temperature. Usually the amount of shrinkage increases as the
temperature of exposure becomes higher. Eventually a temperature will be reached at which the shrinkage becomes excessive. With
excessive shrinkage, the insulating material has definitely exceeded its useful temperature limit. When an insulating material is
applied to a hot surface, the shrinkage will be greatest on the hot face. The differential shrinkage which results between the hotter
and the cooler surfaces often introduces strains and may cause the insulation to warp. High shrinkage may cause excessive warpage
and thereby may induce cracking, both of which are undesirable. High shrinkage may also open gaps at the insulation joints to
an excessive extent rendering the application less efficient and more hazardous. In order to predict the limit of permissible
shrinkage in service, the degree of linear shrinkage to be tolerated by specimens of an insulating material when subjected to
soaking heat must be determined from experience.
4.3 It is recognized that a fixed relation between linear shrinkage under soaking heat and actual shrinkage in service cannot be
established for different types of insulating materials. Generall
...