ASTM C610-17(2023)

Standard Specification for Molded Expanded Perlite Block and Pipe Thermal Insulation

ABSTRACT
This specification covers molded expanded perlite block, fittings, and pipe thermal insulation intended for use on surfaces with temperatures of certain range. The insulation shall not have visible defects that will adversely affect its service qualities. Different test methods shall be performed in order to determine the properties of the block, fitting, and pipe insulations: density, apparent thermal conductivity, linear shrinkage after heat soaking, flexural strength, compressive strength, weight loss by tumbling, moisture content, water absorption after heat aging, surface bearing characteristics, hot-surface performance, and stress corrosion cracking of austenitic stainless steel.
SCOPE
1.1 This specification covers molded expanded perlite block, fittings, and pipe thermal insulation intended for use on surfaces with temperatures between 80 to 1200°F (27 to 649°C).  
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: 28-Feb-2023
• ICS: 91.100.60 - Thermal and sound insulating materials
• Technical Committee: C16 - Thermal Insulation
• Drafting Committee: C16.20 - Homogeneous Inorganic Thermal Insulations

Relations

• Refers: ASTM C168-24 - Standard Terminology Relating to Thermal Insulation
• Effective Date: 15-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 C1763-20 - Standard Test Method for Water Absorption by Immersion of Thermal Insulation Materials
• Effective Date: 01-May-2020
• Refers: ASTM C421-08(2020) - Standard Test Method for Tumbling Friability of Preformed Block-Type and Preformed Pipe-Covering-Type Thermal Insulation
• Effective Date: 01-Mar-2020
• Refers: ASTM C1763-19e1 - Standard Test Method for Water Absorption by Immersion of Thermal Insulation Materials
• Effective Date: 15-Oct-2019
• Refers: ASTM C1763-19 - Standard Test Method for Water Absorption by Immersion of Thermal Insulation Materials
• Effective Date: 15-Oct-2019
• Refers: ASTM C390-08(2019) - Standard Practice for Sampling and Acceptance of Thermal Insulation Lots
• 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 C1617-19 - Standard Practice for Quantitative Accelerated Laboratory Evaluation of Extraction Solutions Containing Ions Leached from Thermal Insulation on Aqueous Corrosion of Metals
• Effective Date: 01-May-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

Overview

ASTM C610-17(2023) - Standard Specification for Molded Expanded Perlite Block and Pipe Thermal Insulation defines the requirements for molded expanded perlite thermal insulation products in block, pipe, and fitting forms. Developed by ASTM International, this standard ensures that expanded perlite insulation delivered for high- and low-temperature thermal applications meets strict quality, performance, and safety guidelines. Intended for use on surfaces with temperatures ranging from 80°F to 1200°F (27°C to 649°C), this specification provides manufacturers, purchasers, and installers with a consistent benchmark for product selection and verification.

Expanded perlite insulation is valued in industrial and commercial settings for its thermal efficiency, fire resistance, lightweight composition, and compatibility with piping, vessels, and equipment. This standard is widely referenced by construction professionals, engineers, and maintenance teams focused on energy management and regulatory compliance.

Key Topics

ASTM C610-17(2023) covers several critical aspects of molded expanded perlite insulation:

• Materials and Composition: Insulation must be primarily made of expanded perlite with silicate binders, with optional reinforcing fibers.
• Product Forms: Includes blocks, pipe segments (split or curved), and various fittings designed to fit standard piping and vessel dimensions.
• Physical and Mechanical Properties: The standard specifies requirements for:
  • Density and dimensions
  • Flexural strength, compressive resistance, and linear shrinkage after heat exposure
  • Weight loss by tumbling and moisture content
  • Apparent thermal conductivity at multiple mean temperatures
  • Water absorption after heat aging
  • Surface burning characteristics and combustibility
  • Resistance to stress corrosion cracking of austenitic stainless steel
• Dimensional Tolerances: Strict tolerances for product length, width, thickness, and concentricity for pipe insulation ensure reliable fit and performance.
• Quality and Workmanship: Insulation products must be free from defects negatively impacting their service life or insulating quality.

Applications

ASTM C610-17(2023) is the go-to specification for:

• Industrial and Commercial Insulation
  • Thermal insulation of high- and low-temperature pipes, tanks, vessels, and equipment in power plants, chemical processing, oil and gas, and HVAC systems
  • Fire-resistant thermal barriers for process piping and high-temperature installations
• Energy Efficiency Projects
  • Reducing heat loss and supporting compliance with energy codes and sustainability guidelines in facilities management
• Retrofit and New Construction
  • Specifying reliable perlite insulation products in project designs for both new construction and upgrades or repairs
• Safety-Critical Environments
  • Applications requiring flame spread and smoke development indices per E84 testing and proven non-combustibility in compliance with E136

Engineers and specifiers choose materials meeting ASTM C610 for their proven performance under variable temperatures, resistance to corrosion in contact with austenitic stainless steel, and robustness in physically demanding settings.

Related Standards

ASTM C610-17(2023) references and aligns with several important ASTM standards:

• ASTM C302 & C303: Methods for determining density and dimensions of insulation
• ASTM C335/C335M, C518, C177: Procedures for measuring steady-state thermal transmission properties
• ASTM C356: Testing linear shrinkage after heat exposure
• ASTM C421: Tumbling friability (durability during handling)
• ASTM C795: Specification for use of thermal insulation with austenitic stainless steel
• ASTM E84 & E136: Surface burning characteristics and combustibility testing

For best results in high-performance thermal insulation systems, professionals should ensure compatibility and compliance with these related standards during design, purchasing, and installation.

Keywords: expanded perlite, molded insulation, pipe insulation, block insulation, thermal insulation, ASTM C610, high-temperature insulation, thermal conductivity, energy efficiency, industrial insulation, fire resistance

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: C610 − 17 (Reapproved 2023)
Standard Specification for
Molded Expanded Perlite Block and Pipe Thermal
Insulation
This standard is issued under the fixed designation C610; 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 C302 Test Method for Density and Dimensions of Pre-
formed Pipe-Covering-Type Thermal Insulation
1.1 This specification covers molded expanded perlite
C303 Test Method for Dimensions and Density of Pre-
block, fittings, and pipe thermal insulation intended for use on
formed Block and Board–Type Thermal Insulation
surfaces with temperatures between 80 to 1200°F (27 to
C335/C335M Test Method for Steady-State Heat Transfer
649°C).
Properties of Pipe Insulation
1.2 The values stated in inch-pound units are to be regarded
C356 Test Method for Linear Shrinkage of Preformed High-
as standard. The values given in parentheses are mathematical
Temperature Thermal Insulation Subjected to Soaking
conversions to SI units that are provided for information only
Heat
and are not considered standard.
C390 Practice for Sampling and Acceptance of Thermal
1.3 This standard does not purport to address all of the
Insulation Lots
safety concerns, if any, associated with its use. It is the
C411 Test Method for Hot-Surface Performance of High-
responsibility of the user of this standard to establish appro-
Temperature Thermal Insulation
priate safety, health, and environmental practices and deter-
C421 Test Method for Tumbling Friability of Preformed
mine the applicability of regulatory limitations prior to use.
Block-Type and Preformed Pipe-Covering-Type Thermal
1.4 This international standard was developed in accor-
Insulation
dance with internationally recognized principles on standard-
C450 Practice for Fabrication of Thermal Insulating Fitting
ization established in the Decision on Principles for the
Covers for NPS Piping, and Vessel Lagging
Development of International Standards, Guides and Recom-
C518 Test Method for Steady-State Thermal Transmission
mendations issued by the World Trade Organization Technical
Properties by Means of the Heat Flow Meter Apparatus
Barriers to Trade (TBT) Committee.
C585 Practice for Inner and Outer Diameters of Thermal
Insulation for Nominal Sizes of Pipe and Tubing
2. Referenced Documents
C795 Specification for Thermal Insulation for Use in Con-
2.1 ASTM Standards:
tact with Austenitic Stainless Steel
C165 Test Method for Measuring Compressive Properties of
C1045 Practice for Calculating Thermal Transmission Prop-
Thermal Insulations
erties Under Steady-State Conditions
C168 Terminology Relating to Thermal Insulation
C1058/C1058M Practice for Selecting Temperatures for
C177 Test Method for Steady-State Heat Flux Measure-
Evaluating and Reporting Thermal Properties of Thermal
ments and Thermal Transmission Properties by Means of
Insulation
the Guarded-Hot-Plate Apparatus
C1616 Test Method for Determining the Moisture Content
C203 Test Methods for Breaking Load and Flexural Proper-
of Organic and Inorganic Insulation Materials by Weight
ties of Block-Type Thermal Insulation
C1617 Practice for Quantitative Accelerated Laboratory
Evaluation of Extraction Solutions Containing Ions
This specification is under the jurisdiction of ASTM Committee C16 on Leached from Thermal Insulation on Aqueous Corrosion
Thermal Insulation and is the direct responsibility of Subcommittee C16.20 on
of Metals
Homogeneous Inorganic Thermal Insulations.
C1763 Test Method for Water Absorption by Immersion of
Current edition approved March 1, 2023. Published March 2023. Originally
Thermal Insulation Materials
approved in 1967. Last previous edition approved in 2017 as C610 – 17. DOI:
10.1520/C0610-17R23.
E84 Test Method for Surface Burning Characteristics of
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Building Materials
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
E136 Test Method for Assessing Combustibility of Materials
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Using a Vertical Tube Furnace at 750 °C
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C610 − 17 (2023)
3. Terminology 6.2.2 Concentricity—The inner bore of the pipe insulation
shall be concentric with the outer cylindrical surface. The
3.1 Definitions—For definitions of general terms related to
deviation from concentricity shall not exceed ⁄8 in. (3.2 mm)
thermal insulation used in this specification, refer to Terminol-
or 5 % of the wall thickness, whichever is greater.
ogy C168.
6.2.3 Half-Section Balance—The plane formed by the split
between half sections shall include the cylindrical axis. Devia-
4. Standard Shapes, Sizes, and Dimensions
tion of the split plane from the cylinder axis over the 36 or
4.1 Molded expanded perlite block, fitting, and pipe thermal 1
39.4-in. (914 or 1000-mm) length shall not exceed ⁄8 in. (3.2
insulation shall be as follows:
mm).
4.1.1 Block—Block shall be furnished in lengths of either 36
7. Workmanship, Finish, and Appearance
or 39.4 in. (914 or 1000 mm), widths of 6 in. (152 mm), 12 in.
(305 mm), 18 in. (457 mm), or 24 in. (610 mm), and in
7.1 Since some requirements for this material are not easily
1 1
thickness from 1 ⁄2 to 6 in. (38 to 152 mm) in increments of ⁄2
defined by a numerical value, the insulation shall not have
in. (13 mm).
visible defects that will adversely affect its service qualities.
4.1.2 Pipe Insulation—Molded expanded perlite pipe insu-
8. Physical Requirements
lation shall be supplied either as hollow cylindrical shapes split
in half lengthwise (in a plane including the cylindrical axis) or
8.1 The insulation shall conform to the physical require-
curved segments. The pipe insulation shall be furnished in
ments in Table 2.
sections or segments in lengths of either 36 or 39.4 in. (914 or
9. Sampling
1000 mm) to fit standard sizes of pipe and tubing, and in
nominal thickness from 1 to 4 in. (25 to 102 mm) in ⁄2-in.
9.1 The insulation shall be sampled in accordance with
(13-mm) increments. Inner and outer diameters of multilayer
Practice C390. Specific provision for sampling shall be agreed
construction shall be specified. Inner and outer diameters shall
upon between the purchaser and the supplier.
be in accordance with those standard dimensions specified in
10. Qualification Requirements
Practice C585. Since outside diameter tolerances differ be-
tween individual manufacturing processes, it is acceptable to
10.1 The following requirements are generally employed
have pipe insulation furnished in two or more layers nested by
for purpose of initial material or product qualification:
the manufacturer. The purchaser shall consult the manufacturer
10.1.1 Flexural strength,
for specific requirements.
10.1.2 Compressive resistance,
4.1.3 Fittings—Molded (expanded insulation fittings shall
10.1.3 Surface burning characteristics,
conform to the inner and outer diameters in accordance with
10.1.4 Linear shrinkage after soaking heat,
Practice C585. Mitered fittings shall be in accordance with
10.1.5 Water absorption after heat aging,
Practice C450.
10.1.6 Apparent thermal conductivity,
10.1.7 Hot-surface performance,
5. Description
10.1.8 Stress corrosion cracking of austenitic stainless steel,
10.1.9 Weight loss by tumbling,
5.1 Composition—molded expanded perlite block, fitting,
10.1.10 Mass loss corrosion rate, and
and pipe thermal insulation shall be composed principally of
10.1.11 Combustibility.
expanded perlite and silicate binders may contain reinforcing
fibers.
11. Acceptance Requirements
11.1 The following requirements are generally employed for
6. Dimensional Tolerances
purposes of acceptance sampling of lots or shipments of
6.1 General—The average tolerances for length, width, and
qualified products:
thickness shall comply with the requirements shown in Table 1.
11.1.1 Density,
6.2 Pipe Insulation—The following additional tolerances 11.1.2 Dimensions,
apply to perlite pipe insulation supplied as half sections: 11.1.3 Workmanship, and
6.2.1 Fit and Closure—When fitted to the appropriate size 11.1.4 Moisture content.
pipe, the longitudinal seam of the pipe insulation shall close to
12. Test Methods
within ⁄16 in. (1.6 mm) along the entire length of the section.
12.1 The properties enumerated in this specification shall be
determined in accordance with the following test methods:
12.1.1 Density:
12.1.1.1 Block Insulation—Test Method C303.
TABLE 1 Dimensional Tolerances
12.1.1.2 Pipe Insulat
...