ASTM C1685-15(2021)

Standard Specification for Pneumatically Applied High-Temperature Fiber Thermal Insulation for Industrial Applications

SCOPE
1.1 This specification covers the composition, thermal performance, sound absorption performance, and physical properties of high-temperature fiber thermal insulation for use at temperatures from ambient to 3000°F (1649°C).  
1.2 The dry, loose high-temperature fibers shall be pneumatically conveyed to a chamber where they are mixed with a water-based chemical binder and then conveyed to a nozzle.  
1.3 The pneumatically applied, high-temperature fiber insulation is intended for use in industrial applications on flat, or nearly flat, surfaces. It is not intended for use on pipes.  
1.4 This specification addresses the use performance of this material in both thermal and acoustical applications.  
1.5 This specification does not address the requirements for fire-resistive insulation, but it does not preclude this material’s use in that capacity.  
1.6 This is a material specification only and is not intended to cover methods of application that are provided by the manufacturer.  
1.7 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.  
1.8 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.  
1.9 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: 28-Feb-2021
• ICS: 27.220 - Heat recovery. Thermal insulation
• Technical Committee: C16 - Thermal Insulation
• Drafting Committee: C16.23 - Blanket and Loose Fill Insulation

Relations

• Refers: ASTM C168-24 - Standard Terminology Relating to Thermal Insulation
• Effective Date: 15-Apr-2024
• Refers: ASTM C133-24 - Standard Test Methods for Cold Crushing Strength and Modulus of Rupture of Refractories
• Effective Date: 01-Apr-2024
• Refers: ASTM E136-24a - Standard Test Method for Assessing Combustibility of Materials Using a Vertical Tube Furnace at 750 °C
• Effective Date: 01-Mar-2024
• Refers: ASTM C390-08(2024) - Standard Practice for Sampling and Acceptance of Thermal Insulation Lots
• Effective Date: 01-Mar-2024
• Refers: ASTM E136-24 - Standard Test Method for Assessing Combustibility of Materials Using a Vertical Tube Furnace at 750 °C
• Effective Date: 01-Feb-2024
• Refers: ASTM E84-23d - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Dec-2023
• Refers: ASTM E84-23c - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Sep-2023
• Refers: ASTM C390-08(2019) - Standard Practice for Sampling and Acceptance of Thermal Insulation Lots
• Effective Date: 01-Sep-2019
• Refers: ASTM C1104/C1104M-19 - Standard Test Method for Determining the Water Vapor Sorption of Unfaced Mineral Fiber Insulation
• Effective Date: 01-Sep-2019
• Refers: ASTM E84-19b - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Jul-2019
• Refers: ASTM E84-19a - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 15-Apr-2019
• Refers: ASTM C1045-19 - Standard Practice for Calculating Thermal Transmission Properties Under Steady-State Conditions
• Effective Date: 01-Apr-2019
• Refers: ASTM C411-19 - Standard Test Method for Hot-Surface Performance of High-Temperature Thermal Insulation
• Effective Date: 01-Mar-2019
• Refers: ASTM E84-19 - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Mar-2019
• Refers: ASTM E136-19 - Standard Test Method for Assessing Combustibility of Materials Using a Vertical Tube Furnace at 750°C
• Effective Date: 01-Feb-2019

Overview

ASTM C1685-15(2021): Standard Specification for Pneumatically Applied High-Temperature Fiber Thermal Insulation for Industrial Applications establishes the requirements for composition, thermal performance, sound absorption, and physical properties of high-temperature fiber insulation applied pneumatically. This standard covers insulation materials suitable for continuous operating temperatures from ambient up to 3000°F (1649°C), making it highly valuable for demanding industrial environments. The specification guides manufacturers, contractors, and facility managers in selecting and qualifying insulation used on flat or nearly flat industrial surfaces to ensure consistent quality, safety, and performance.

Key features of this standard include rigorous performance metrics for thermal insulation, detailed sound absorption requirements, and specific test methods recognized internationally for product qualification and quality assurance.

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Key Topics

• Composition and Manufacturing
  High-temperature insulation under this standard comprises loose inorganic fibers such as silica, alumina, calcium, and magnesium, combined with a water-based chemical binder. The fibers and binder are pneumatically mixed and applied to the installation surface via a nozzle.

• Types and Grades
  Material types are categorized by composition and maximum use temperature:

  • Type I: Calcium Magnesium Silicate (2012°F/1100°C)
  • Type II: Magnesium Silicate (2300°F/1260°C)
  • Type III: Aluminum Silicate (3000°F/1649°C)

  Additionally, insulation is provided as Grade A or Grade B, differentiated by thermal conductivity and sound absorption properties.

• Thermal Performance
  Insulation must demonstrate low thermal conductivity across a range of temperatures and resist shrinkage, water vapor sorption, and surface burning.

• Sound Absorption
  The standard includes quantitative requirements for sound absorption coefficients and noise reduction, making it suitable for combined thermal and acoustical applications.

• Physical and Mechanical Properties
  Requirements cover compressive resistance, cold crush strength, linear shrinkage, water vapor sorption, and non-combustibility.

• Application Scope
  The material is designed specifically for industrial applications on flat or nearly flat surfaces and is not intended for use on pipes.

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Applications

Pneumatically applied high-temperature fiber thermal insulation is primarily used in industrial settings requiring robust, high-performance thermal management and sound control. Typical applications include:

• Furnace walls, kiln linings, and high-temperature process equipment in foundries and refineries
• Industrial ovens, dryers, and heat-treatment chambers
• Flat surfaces in power plants and chemical processing facilities
• Areas requiring both thermal insulation and noise reduction

This insulation is ideal where traditional preformed insulating products are impractical or insufficient, and where rapid, uniform application is a priority. The standard ensures that products maintain their thermal and acoustical performance throughout their service life, even under harsh operating conditions.

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Related Standards

Several ASTM standards are referenced by ASTM C1685-15(2021) for terminology, test methods, and performance verification. Key related standards include:

• ASTM C71: Terminology Relating to Refractories
• ASTM C133: Test Methods for Cold Crushing Strength and Modulus of Rupture
• ASTM C165: Measuring Compressive Properties of Thermal Insulations
• ASTM C168: Terminology Relating to Thermal Insulation
• ASTM C177, C201, C1113: Thermal Conductivity Test Methods
• ASTM C356: Linear Shrinkage Testing
• ASTM C423: Sound Absorption Coefficients by the Reverberation Room Method
• ASTM E84: Surface Burning Characteristics
• ASTM E605: Thickness and Density of Sprayed Fire-Resistive Materials
• ISO 8894: Thermal Conductivity by the Hot Wire Method
• CAN/ULC–S102–07: Surface Burning Characteristics of Building Materials

These standards provide detailed procedures for product testing, ensuring that high-temperature fiber thermal insulation products meet consistent international quality and performance benchmarks.

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By adhering to ASTM C1685-15(2021), manufacturers, specifiers, and contractors ensure safety, regulatory compliance, and superior performance in industrial high-temperature insulation applications.

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:C1685 −15 (Reapproved 2021)
Standard Specification for
Pneumatically Applied High-Temperature Fiber Thermal
Insulation for Industrial Applications
This standard is issued under the fixed designation C1685; 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 2. Referenced Documents
1.1 This specification covers the composition, thermal 2.1 ASTM Standards:
performance, sound absorption performance, and physical C71 Terminology Relating to Refractories
properties of high-temperature fiber thermal insulation for use C133 Test Methods for Cold Crushing Strength and Modu-
at temperatures from ambient to 3000°F (1649°C). lus of Rupture of Refractories
C165 Test Method for Measuring Compressive Properties of
1.2 The dry, loose high-temperature fibers shall be pneu-
Thermal Insulations
matically conveyed to a chamber where they are mixed with a
C168 Terminology Relating to Thermal Insulation
water-based chemical binder and then conveyed to a nozzle.
C177 Test Method for Steady-State Heat Flux Measure-
1.3 The pneumatically applied, high-temperature fiber insu-
ments and Thermal Transmission Properties by Means of
lation is intended for use in industrial applications on flat, or
the Guarded-Hot-Plate Apparatus
nearly flat, surfaces. It is not intended for use on pipes.
C201 Test Method for Thermal Conductivity of Refractories
1.4 This specification addresses the use performance of this C356 Test Method for Linear Shrinkage of Preformed High-
Temperature Thermal Insulation Subjected to Soaking
material in both thermal and acoustical applications.
Heat
1.5 This specification does not address the requirements for
C390 Practice for Sampling and Acceptance of Thermal
fire-resistive insulation, but it does not preclude this material’s
Insulation Lots
use in that capacity.
C411 Test Method for Hot-Surface Performance of High-
1.6 This is a material specification only and is not intended
Temperature Thermal Insulation
to cover methods of application that are provided by the
C423 Test Method for SoundAbsorption and SoundAbsorp-
manufacturer.
tion Coefficients by the Reverberation Room Method
C447 Practice for Estimating the Maximum Use Tempera-
1.7 The values stated in inch-pound units are to be regarded
ture of Thermal Insulations
as standard. The values given in parentheses are mathematical
C665 Specification for Mineral-Fiber Blanket Thermal Insu-
conversions to SI units that are provided for information only
lation for Light Frame Construction and Manufactured
and are not considered standard.
Housing
1.8 This standard does not purport to address all of the
C795 Specification for Thermal Insulation for Use in Con-
safety concerns, if any, associated with its use. It is the
tact with Austenitic Stainless Steel
responsibility of the user of this standard to establish appro-
C1045 Practice for Calculating Thermal Transmission Prop-
priate safety, health, and environmental practices and deter-
erties Under Steady-State Conditions
mine the applicability of regulatory limitations prior to use.
C1104/C1104M Test Method for Determining the Water
1.9 This international standard was developed in accor-
Vapor Sorption of Unfaced Mineral Fiber Insulation
dance with internationally recognized principles on standard-
C1113 Test Method for Thermal Conductivity of Refracto-
ization established in the Decision on Principles for the
ries by Hot Wire (Platinum Resistance Thermometer
Development of International Standards, Guides and Recom-
Technique)
mendations issued by the World Trade Organization Technical
E84 Test Method for Surface Burning Characteristics of
Barriers to Trade (TBT) Committee.
Building Materials
This specification is under the jurisdiction of ASTM Committee C16 on
Thermal Insulation and is the direct responsibility of Subcommittee C16.23 on
Blanket and Loose Fill Insulation. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved March 1, 2021. Published April 2021. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2008. Last previous edition approved in 2015 as C1685 – 15. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/C1685-15R21. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1685−15 (2021)
TABLE 1 Performance Requirements (Excluding Acoustical)
Maximum Use Temperature, °F (°C)
Type I Type II Type III
2012 (1100) 2300 (1260) 3000 (1649)
Apparent Thermal Conductivity, maximum Btu-in./h · ft · °F (W/m · K) at mean temperature, °F (°C), for all three types
Grade A Grade B
75 (24) 0.40 (0.058) 0.18 (0.026)
200 (93) 0.44 (0.063) 0.25 (0.036)
400 (204) 0.54 (0.078) 0.38 (0.055)
600 (316) 0.72 (0.104) 0.53 (0.077)
800 (427) 1.00 (0.144) 0.71 (0.10)
1000 (538) 1.37 (0.197) 0.90 (0.13)
1200 (649) 1.82 (0.262) 1.12 (0.16)
1400 (760) 2.36 (0.340) 1.35 (0.19)
1600 (871) 2.99 (0.431) 1.61 (0.23)
Maximum Compressive Resistance, at 10% deformation, min, lb/ft (kPa), for all three types Grade A in 50 (2.4)
accordance with Test Method C165
Maximum Cold Crush, min., psi (Pa), for all three Types, Grade B, in accordance with Test Method C133
Modulus of Rupture 10 (0.48)
Cold Crush 13 (0.62)
Linear Shrinkage, at maximum use temperature, %, for all three types and both Grades A and B 5.0
Water Vapor Sorption, maximum, % by weight, for all three types and both Grades A and B 5.0
Surface Burning Characteristics, for all three types and both Grades A and B:
Flame Spread Index, maximum 25
Smoke Developed Index, maximum 50
E136 TestMethodforAssessingCombustibilityofMaterials molten state into fibrous form. The liquid binder is made from
Using a Vertical Tube Furnace at 750°C inorganic materials: water, colloidal silica, and less than 2% of
E605 Test Methods for Thickness and Density of Sprayed an organic foaming agent.
Fire-Resistive Material (SFRM) Applied to Structural
4.2 Types—The product is separated into types based on the
Members
chemistry and temperature use limit:
E2231 Practice for Specimen Preparation and Mounting of
Chemical Upper Use
Pipe and Duct Insulation Materials to Assess Surface
Type Composition Temperature,
Burning Characteristics °F (°C)
2.2 Other Standards: I Calcium Magnesium Silicate 2012 (1100)
II Magnesium Silicate 2300 (1260)
ISO 8894 Thermal Conductivity by the Hot Wire Method;
III Aluminum Silicate 3000 (1649)
Part1CrossedWireMethod,Part2ParallelWireMethod
4.3 The liquid binder shall be added in sufficient quantity to
CAN/ULC–S102–07 Standard Method of Test for Surface
provide the fibers with necessary adhesion to the applied
Burning Characteristics of Building Materials andAssem-
4 surface, cohesion to one another, and the required physical
blies
properties of the installed, dry insulation.
3. Terminology
4.4 There shall be two different grades of material, GradeA
and Grade B, differentiated by different thermal conductivity,
3.1 Definitions—For definitions of terms used in this
different sound absorption coefficients, and different noise
specification, see Terminology C71 and C168.
reduction coefficients.
3.2 Definitions of Terms Specific to This Standard:
3.3 cured, n—state or condition of the finished product after 5. Physical Properties
the liquid vehicle has been evaporated to a constant mass.
5.1 For pneumatically applied, high-temperature thermal
3.4 pneumatically applied, v—use of air to convey the
insulation, it is possible that the properties of density and
fibrous insulation to a nozzle and then from a nozzle to the
apparent thermal conductivity will vary with the manufacturer.
intended surface to be insulated.
Minimum acceptable value of density and maximum accept-
able values of thermal conductivity shall be stated by the
4. Materials and Manufacture
manufacturerbeforesaleandshallbetestedinaccordancewith
4.1 Composition—The basic types of materials shall be 9.1. (See Table 1.)
loose inorganic fibers combined with a liquid, water-based
5.2 Maximum Use Temperature—When tested in accor-
binder. The fibers are made from mineral substances such as
dance with 9.1, the high-temperature fiber insulation shall not
silica, alumina, calcium, and magnesium processed from the
warp, flame, or glow during hot surface exposure. No evidence
of melting or fiber degradation shall be evident upon post–test
inspection.
Available from International Organization for Standardization (ISO), 1, ch. de
la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http://
5.3 Maximum Exothermic Temperature Rise—When tested
www.iso.ch.
inaccordancewith9.1,theinternaltemperatureshallnotatany
AvailablefromOttawaStandardsandGovernmentRelationsOffice440Laurier
Ave. West, Suite 200 Ottawa ON K1R 7X6, http://www.ulc.ca. time exceed the hot surface temperature by more than 200°F
C1685−15 (2021)
TABLE 2 Minimum Values of Sound Absorption Coefficients by
6.3 The substrat
...