ISO 18959:2025

Thermal insulation products - Rigid nano-microporous insulation for industrial applications - Specification

This document specifies the requirements for factory-made rigid nano-microporous insulation, which are used for the thermal insulation of industrial applications on surface at temperatures from 100 °C to 1 150 °C. This document specifies insulation that exhibits thermal insulating performance through nano-sized pore composite material comprising a blend of inorganic powder, fibres and opacifiers. The products are delivered as board or pipe section type. This document describes product characteristics and includes procedures for testing, evaluation of conformity, marking and labelling. This document does not specify the required level of a given property to be achieved by a product to demonstrate fitness for purpose in a particular application. The levels required for a given application are to be found in regulations or non-conflicting standards.

Produits isolants thermiques — Isolation nano-microporeuse rigide pour applications industrielles — Spécifications

General Information

• Status: Published
• Publication Date: 31-Aug-2025
• ICS: 91.100.60 - Thermal and sound insulating materials
• Technical Committee: ISO/TC 163/SC 3 - Thermal insulation products, components and systems
• Drafting Committee: ISO/TC 163/SC 3 - Thermal insulation products, components and systems
• Current Stage: 6060 - International Standard published
• Start Date: 01-Sep-2025
• Due Date: 10-Nov-2025
• Completion Date: 01-Sep-2025

Overview

ISO 18959:2025 - Thermal insulation products - Rigid nano‑microporous insulation for industrial applications - Specification defines factory-made rigid nano‑microporous insulation for industrial surfaces operating from 100 °C to 1 150 °C. It covers product form (boards and pipe sections), material description (nano‑microporous composite of inorganic powder, fibres and opacifiers), required product characteristics, test procedures, conformity evaluation, and marking and labelling. The standard does not prescribe fitness‑for‑purpose levels for specific installations; those are set by regulations or application‑specific standards.

Key topics and requirements

• Product scope: Rigid nano‑microporous insulation (RMI) supplied as boards or pipe sections for high‑temperature industrial insulation.
• Temperature classification: Products are classified by classification temperature (Type950, Type1050, Type1150) determined by permanent linear change testing.
• Thermal performance:
  • Manufacturer must declare thermal conductivity (λ) and provide a conductivity vs. temperature curve (typically 200–800 °C) per ISO 13787.
  • Measured by ISO 8302 (boards) or ISO 8497 (pipe sections). At a test mean temperature of 500 °C, λD ≤ 0.036 W/(m·K) for Type950 and ≤ 0.045 W/(m·K) for other types.
• Dimensional and geometric tolerances:
  • Length/width tolerances vary by size (e.g., ±5 mm to ±10 mm depending on dimensions).
  • Squareness, flatness and linearity limits (boards: squareness ≤ 6 mm/m; thickness squareness ≤ 2 mm; flatness ≤ 3 mm; pipe section linearity ≤ 3 mm or 0.6%).
• Mechanical and physical properties:
  • Permanent linear change on heating ≤ 3.0 % at the classification temperature.
  • Apparent density tolerance ±10 % from nominal (ISO 29470).
  • Compressive stress at 10 % deformation (ISO 29469) must meet declared levels (e.g., CS(10\Y) 200–500 kPa).
• Chemical considerations:
  • Trace water‑soluble chloride levels must be declared and not exceeded (ISO 12624) - important for corrosion-sensitive substrates like stainless steel.
• Conformity & quality:
  • Sampling, conditioning, testing procedures and factory production control (Annex A) are specified.
  • Requirements for marking and labelling to support traceability and specification compliance.

Applications and users

Practical applications include high‑temperature industrial insulation for furnaces, petrochemical plants, power generation, process vessels and piping where low thermal conductivity and compact insulation thickness are required. Typical users:

• Insulation manufacturers (product specification and FPC)
• Design engineers and thermal insulation specifiers
• Procurement teams and project managers selecting insulation materials
• Test laboratories and conformity assessors
• Regulatory authorities and plant safety engineers

Related standards

ISO 18959:2025 references several test and vocabulary standards, including:

• ISO 8302, ISO 8497 (thermal conductivity tests)
• ISO 13787 (declared thermal conductivity)
• ISO 9229 (vocabulary)
• ISO 12624 (water‑soluble ions)
• ISO 29465 / 29466 / 29469 / 29470 (dimensional, compression, density tests)

Keywords: ISO 18959:2025, rigid nano‑microporous insulation, thermal insulation, industrial applications, thermal conductivity, high‑temperature insulation, product specification, testing and conformity.

Standards Content (Sample)

International
Standard
ISO 18959
First edition
Thermal insulation products —
2025-09
Rigid nano-microporous insulation
for industrial applications —
Specification
Produits isolants thermiques — Isolation nano-microporeuse
rigide pour applications industrielles — Spécifications
Reference number
© ISO 2025
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Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, symbols and abbreviated terms . 1
3.1 Terms and definitions .2
3.2 Symbols and units .2
3.3 Abbreviated terms .2
3.3.1 Abbreviated terms for general usage.2
3.3.2 Abbreviated terms for declared properties .2
4 Requirements . 3
4.1 General .3
4.2 Classification .3
4.3 Permanent linear change .3
4.4 Thermal conductivity .3
4.5 Linear dimensions .3
4.6 Squareness .4
4.7 Flatness .4
4.8 Pipe section linearity .4
4.9 Density .4
4.10 Compressive stress at 10 % deformation .4
4.11 Corrosiveness to steel .4
5 Test methods . 5
5.1 Sampling .5
5.2 Conditioning.5
5.3 Testing .5
5.3.1 General .5
5.3.2 Thermal conductivity .5
6 Designation code . . 6
7 Evaluation of conformity . . 6
8 Marking and labelling . 6
Annex A (normative) Factory production control . 8
Bibliography . 9

iii
Foreword
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This document was prepared by Technical Committee ISO/TC 163, Thermal performance and energy use in
the built environment, Subcommittee SC 3, Thermal insulation products, components and systems.
Any feedback or questions on this document should be directed to the user’s national standards body. A
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iv
International Standard ISO 18959:2025(en)
Thermal insulation products — Rigid nano-microporous
insulation for industrial applications — Specification
1 Scope
This document specifies the requirements for factory-made rigid nano-microporous insulation, which
are used for the thermal insulation of industrial applications on surface at temperatures from 100 °C to
1 150 °C. This document specifies insulation that exhibits thermal insulating performance through nano-
sized pore composite material comprising a blend of inorganic powder, fibres and opacifiers. The products
are delivered as board or pipe section type.
This document describes product characteristics and includes procedures for testing, evaluation of
conformity, marking and labelling.
This document does not specify the required level of a given property to be achieved by a product to
demonstrate fitness for purpose in a particular application. The levels required for a given application are to
be found in regulations or non-conflicting standards.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 8302, Thermal insulation — Determination of steady-state thermal resistance and related properties —
Guarded hot plate apparatus
ISO 8497, Thermal insulation — Determination of steady-state thermal transmission properties of thermal
insulation for circular pipes
ISO 9229, Thermal insulation — Vocabulary
ISO 12624, Thermal insulating products for building equipment and industrial installations — Determination of
trace quantities of water-soluble chloride, fluoride, silicate, sodium ions and pH
ISO 13787, Thermal insulation products for building equipment and industrial installations — Determination o
...