ASTM C1728-25a PDF

Full title and description

ASTM C1728-25a — Standard Specification for Flexible Aerogel Insulation. This specification establishes classification and performance requirements for flexible aerogel thermal insulation products (sheets, blankets, and composites), including mechanical, chemical, dimensional and thermal-property criteria and acceptable tolerances for Types I, II, and III flexible aerogel insulation.

Abstract

This standard specifies required properties and test-performance limits for flexible aerogel insulation intended for applications from cryogenic up to high temperatures. It addresses thickness, density, flexibility, thermal performance, and requirements for use of vapor retarders in below-ambient service to prevent moisture-related degradation.

General information

• Status: Active.
• Publication date: December 1, 2025 (text includes amendments through December 17, 2025).
• Publisher: ASTM International.
• ICS / categories: 91.100.60 (Thermal and sound insulating materials).
• Edition / version: C1728-25a.
• Number of pages: 5.

Scope

This specification covers classification and performance requirements for flexible aerogel thermal insulation intended for continuous exposure temperatures ranging approximately from −321°F (−196°C) up to 1200°F (649°C). The scope includes dimensional tolerances, mechanical and chemical property limits, and performance criteria for multiple product types; it also requires consideration of vapor retarders or barriers for below‑ambient applications to prevent moisture migration and system non‑performance.

Key topics and requirements

• Classification of flexible aerogel insulation into Types I, II, and III with associated performance classes.
• Thermal performance limits and testing requirements covering a wide temperature range from cryogenic to high temperature.
• Dimensional, thickness and density requirements and acceptable tolerances for sheets and blankets.
• Mechanical and chemical property criteria (flexibility, water retention/behavior, handling).
• Requirement to use protective vapor retarders or barriers for below‑ambient service to control moisture migration and prevent system degradation.
• Recent committee activity proposes explicit language on interpretation of significant digits in test data (alignment with Practice E29).

Typical use and users

Used by insulation manufacturers, product specifiers, mechanical and chemical engineers, testing laboratories, contractors, and procurement teams specifying high‑performance thermal insulation for piping, vessels, HVAC systems, cryogenic systems, process equipment, and applications requiring low thermal conductivity and flexible form factors.

Related standards

References and related guidance are drawn from other ASTM C16 committee standards and test practices relevant to thermal insulation and material characterization (for example, referenced test methods and Practice E29 for treatment of significant digits). Users should consult the normative references listed in the standard for specific test methods and companion material specifications.

Keywords

aerogel, flexible aerogel, aerogel blanket, insulation, thermal insulation, pipe insulation, sheet insulation, thermal conductivity, water retention, flexible blanket, C1728.

FAQ

Q: What is this standard?

A: ASTM C1728-25a is the ASTM International standard specification that sets classification and performance requirements for flexible aerogel thermal insulation products.

Q: What does it cover?

A: It covers product types (sheets, blankets, composites), mechanical and chemical property limits, dimensional tolerances, thermal performance across a wide temperature range (approximately −321°F to 1200°F), and guidance on using vapor retarders for below‑ambient service.

Q: Who typically uses it?

A: Manufacturers, designers, specifiers, testing labs, contractors and owners who select or verify flexible aerogel insulation for cryogenic, industrial, commercial HVAC and high‑temperature applications.

Q: Is it current or superseded?

A: It is listed as an active ASTM standard (C1728-25a), published December 1, 2025 with amendments recorded through December 17, 2025. Users should confirm the edition and any subsequent revisions before relying on the specification.

Q: Is it part of a series?

A: Yes. It is part of ASTM material standards under Committee C16 (thermal insulation materials) and references related test methods and practices maintained by ASTM.

Q: What are the key keywords?

A: Aerogel, flexible, blanket, insulation, thermal conductivity, pipe insulation, sheet, C1728.