ASTM C1427-21

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: C1427 − 16 C1427 − 21
Standard Specification for
Extruded Preformed Flexible Cellular Polyolefin Thermal
Insulation in Sheet and Tubular Form
This standard is issued under the fixed designation C1427; 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 specification covers extruded preformed flexible cellular polyolefin thermal insulation operating temperatures from
–150°F to 200°F (–101°C to 93°C). For specific applications, the actual temperature limit shall be agreed upon between the
manufacturer and the purchaser.
1.2 The use of thermal insulation materials covered by this specification are governed by codes and standards that address fire
performance. Contact manufacturer for specific performance of product at the intended use thickness.
1.3 This specification covers the physical properties of preformed flexible cellular polyolefin thermal insulation, which have been
deemed mandatory for thermal design. Physical properties such as density and coefficient of thermal expansion (CTE) have been
deemed nonmandatory for thermal design. Nonmandatory physical properties have been included in Appendix X1 for information
purposes only.
1.4 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.
1.5 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.6 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
2.1 ASTM Standards:
C168 Terminology Relating to Thermal Insulation
C177 Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the
Guarded-Hot-Plate Apparatus
C335 Test Method for Steady-State Heat Transfer Properties of Pipe Insulation
C390 Practice for Sampling and Acceptance of Thermal Insulation Lots
This specification is under the jurisdiction of ASTM Committee C16 on Thermal Insulation and is the direct responsibility of Subcommittee C16.22 on Organic and
Nonhomogeneous Inorganic Thermal Insulations.
Current edition approved Dec. 1, 2016March 1, 2021. Published January 2017March 2021. Originally approved in 1999. Last previous edition approved in 20132016 as
C1427 – 13.C1427 – 16. DOI: 10.1520/C1427-16.10.1520/C1427-21.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1427 − 21
C411 Test Method for Hot-Surface Performance of High-Temperature Thermal Insulation
C447 Practice for Estimating the Maximum Use Temperature of Thermal Insulations
C518 Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus
C534 Specification for Preformed Flexible Elastomeric Cellular Thermal Insulation in Sheet and Tubular Form
C585 Practice for Inner and Outer Diameters of Thermal Insulation for Nominal Sizes of Pipe and Tubing
C670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
C1045 Practice for Calculating Thermal Transmission Properties Under Steady-State Conditions
C1058 Practice for Selecting Temperatures for Evaluating and Reporting Thermal Properties of Thermal Insulation
C1114 Test Method for Steady-State Thermal Transmission Properties by Means of the Thin-Heater Apparatus
C1303 Test Method for Predicting Long-Term Thermal Resistance of Closed-Cell Foam Insulation
C1304 Test Method for Assessing the Odor Emission of Thermal Insulation Materials
C1763 Test Method for Water Absorption by Immersion of Thermal Insulation Materials
D883 Terminology Relating to Plastics
D1622 Test Method for Apparent Density of Rigid Cellular Plastics
D1667 Specification for Flexible Cellular Materials—Poly (Vinyl Chloride) Foam (Closed-Cell)
D3575 Test Methods for Flexible Cellular Materials Made from Olefin Polymers
E84 Test Method for Surface Burning Characteristics of Building Materials
E96/E96M Test Methods for Water Vapor Transmission of Materials
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E228 Test Method for Linear Thermal Expansion of Solid Materials With a Push-Rod Dilatometer
E456 Terminology Relating to Quality and Statistics
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E2231 Practice for Specimen Preparation and Mounting of Pipe and Duct Insulation Materials to Assess Surface Burning
Characteristics
2.2 Other Standards:
CAN/ULC-S102.2 Standard Method of Test for Surface Burning Characteristics of Flooring, Floor Coverings and
Miscellaneous Materials and Assemblies.
3. Terminology
3.1 Definitions—Terms used in this specification are defined in Terminology C168 and in Terminology D883.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 polyolefin—polymers made by the polymerization of olefins, such as ethylene or propylene or copolymerization of olefins
with other monomers.
3.2.2 cellular polyolefin—a cellular plastic composed primarily of olefin material, processed to form a flexible foam with a closed
cell construction.
3.2.2.1 Discussion—
These materials are considered foam plastics.
3.2.3 natural skin—continuous polymer surface or skin naturally occurring as a result of the extrusion or production process, also
referred to as “integral skin.”
3.2.4 flexible cellular—a flexible cellular organic polymeric material will not rupture within 60 s when a specimen 8 by 1 by 1
in. (200 by 25 by 25 mm) is bent around a 1-in. (25-mm) diameter mandrel at a uniform rate of one lap in 5 s in the form of a
helix at a temperature between 65 and 85°F (18 and 29°C).
4. Classification
4.1 The preformed flexible cellular polyolefin thermal insulation shall be of the following types:
4.1.1 Type I—tubular.
4.1.2 Type II—sheet.
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5. Material
5.1 These products shall be extruded flexible cellular polyolefin materials.
5.2 These products are expanded with hydrochlorofluorocarbon gases, hydrofluorocarbon gases, hydrocarbon gases, chemical
blowing agents, atmospheric gases, or combinations thereof. These gases will diffuse from the insulation with time after
production.
5.3 Extruded flexible cellular polyolefin materials shall be of uniform density. Even though these materials will have a smooth skin
surface on one or both sides, they are to be considered homogeneous for the purposes of determining thermal performance.
6. Physical Requirements
6.1 Qualification Requirements:
6.1.1 Thermal conductivity, water vapor permeability, and linear shrinkage, physical properties listed in Table 1 are defined as
qualification requirements (refer to Practice C390, Section 5).
6.2 Inspection Requirements:
6.2.1 The requirements for water absorption listed in Table 1 is defined as inspection requirements (refer to Practice C390,
Sections 5 Classification of Requirements and Section 7, Acceptance for Inspection Requirements.)
6.2.2 All dimensional requirements shall be as described in Section 7 and Table 2.
6.2.3 All workmanship, finish and appearance requirements shall be as described in Section 8.
6.2.4 Compliance with inspection requirements shall be in accordance with Practice C390.
6.2.5 Both Type I and Type II insulations shall conform to the respective physical property requirements listed in Table 1.
6.3 The material shall be free of objectionable odors at all temperatures within the recommended use range when tested according
to Test Method C1304.
TABLE 1 Physical Property Requirements (Type I—Tubular and
Type II—Sheet)
NOTE 1—The values stated in Table 1 are not always appropriate as
design values. For specific design recommendations using a particular
product and for supporting documentation, consult the manufacturer.
Property Unit Requirement
Use temperature, max °F (°C) 200 (93)
Use temperature, min °F (°C) –150 (–101)
Thermal conductivity, max.
At a mean temperature of:
–120°F (–84°C) Btu-in./hr-ft -°F 0.29 (0.042)
0°F (–18°C) (W/m K) 0.33 (0.048)
75°F (24°C) 0.35 (0.050)
120°F (49°C) 0.37 (0.053)
Water-vapor permeability, perm-in 0.05
–9
max. (g/Pa s m) (7.29 × 10 )
Water absorption, max., % by volume 0.2
linear shrinkage, % linear change 7.0
at maxiumum
use temperature.
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TABLE 2 Dimensional Tolerances, in. (mm)
Type I
Inside diameter:
5 1
Up to ⁄8 (16) incl. + ⁄8 (+ 3) –0 (–0)
3 1 3
⁄4 (19) to 1- ⁄2 (38) incl. + ⁄16 (+ 5) –0 (–0)
5 3 1
1- ⁄8 (41) to 2- ⁄8 (60) incl. + ⁄4 (+ 6) –0 (–0)
3 3
Over 2- ⁄8 (60) + ⁄8 (+ 10) –0 (–0)
Wall thicknesses:
3 1
Up to ⁄4 (19) + ⁄8 (+ 3) –0 (–0)
3 3
⁄4 and over (19) + ⁄16 (+ 5) –0 (–0)
Length: +3 (+ 75) –1 (–25)
Type II
Thickness:
1 1
Up to ⁄2 (13) incl. ± ⁄16 ( 2)
1 3
Over ⁄2 (13) ± ⁄32 ( 3)
Length and width: ± 3 %
6.4 Surface Burning Characteristics:
6.4.1 Surface burning characteristics shall be tested for the thickness supplied in accordance with Test Method E84. For
applications in Canada test to CAN/ULC-S102.2. When the referenced Canadian document in this specification is referred to in
applicable Canadian building codes, the editions, referenced by those building codes shall govern. The results shall be reported.
See Section 1 of Test Method E84 for information regarding the applicability of this test method for use with cellular plastics and
Practice E2231 for specimen mounting methods. This test does not always define the hazard potentially resulting from burning of
preformed flexible cellular polyolefin thermal insulation under actual fire conditions. It is retained for reference in this specification
as laboratory test data required by applicable codes and regulations.
6.4.2 Preformed flexible cellular polyolefin thermal insulation is an organic material and is combustible. Do not expose it to flames
or other ignition sources. The fire performance of the material shall be addressed through fire test requirements established by the
appropriate governing documents.
6.4.3 It is possible the surface burning characteristics of the materials are different in the vertical orientation from those in the
horizontal orientation.
7. Standard Shapes, Sizes and Dimensions
7.1 Type I—Tubular materials are manufactured in 36, 60 or 72-in. (0.91, 1.52 or 1.83-m) standard lengths, as well as, continuous
lengths. Tubular insulation is manufactured for pipe sizes up to 4-in. (100–mm) nominal pipe size (NPS) with wall thickness up
to 1-in. (25.4–mm).
7.2 Type II—Sheet and roll material are manufactured in thickness up to 1 in. (25 mm). Sheet insulation is manufactured in the
following sizes: 36 by 48 in. (0.91 by 1.22 m) and 48-in. (1.22-m) wide continuous lengths.
7.3 Actual dimensions and tolerances shall be agreed upon between the manufacturer and the purchaser. The Procedure Section
and Pipe and Tubing Diameter Section of Practice C585 is beneficial in some cases in determining the actual dimensions required.
7.4 The insulation dimensions shall conform to Table 2 unless otherwise agreed upon between the supplier and the purchaser.
8. Surface
8.1 Type I—All surfaces (except ends and slits that are mechanically cut) shall have natural skins.
8.2 Type II—Sheet material is manufactured either without skins, with skin on one side or with skin on two sides. The surface shall
be at the manufacturer’s option, unless otherwise specified.
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9. Workmanship, Finish, and Appearance
9.1 The insulation shall be free of visual defects that will adversely affect the service performance.
10. Sampling
10.1 The insulation shall be sampled in accordance with Practice C390. Details shall be agreed upon between the purchaser and
the supplier.
10.2 When possible, the insulation shall be tested in the fo
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