Overview
EN ISO 12629:2022 - "Thermal insulating products for building equipment and industrial installations - Determination of water vapour transmission properties of preformed pipe insulation" - is a CEN-endorsed international test standard that specifies the equipment, conditioning and steady‑state test procedure for measuring water vapour transmission of preformed pipe insulation. It applies to thermal insulating products that are homogeneous in mass distribution and to products with integral skins or adhered facings. The standard replaces earlier regional documents and aligns test methods and reporting across manufacturers and test laboratories.
Key topics and requirements
- Scope and applicability: Test method for preformed pipe insulation used in building services and industrial installations, intended for homogeneous materials and products with facings.
- Apparatus and test conditions: Defines required equipment and the steady‑state conditions under which measurements must be made (temperature, humidity, thickness).
- Test specimens and conditioning: Specifies specimen dimensions, number of specimens and conditioning procedures prior to testing.
- Measured quantities and calculations:
- Water vapour flow rate (G)
- Density of vapour flow rate (g)
- Water vapour permeance (W) and its inverse, water vapour resistance (Z)
- Water vapour permeability (δ = W · d)
- Water vapour diffusion resistance factor (μ)
- Procedure and data expression: How to assemble specimens, run the steady‑state test, calculate results and report uncertainty/accuracy of measurement.
- Reporting: Minimum data to include in the test report to ensure reproducibility and comparability.
Practical applications
- Compare and select preformed pipe insulation with appropriate water‑vapour properties to prevent condensation and corrosion under insulation (CUI).
- Provide standardized product data (permeance, permeability, μ‑value) for technical datasheets, tender documents and compliance with building regulations.
- Support quality control and R&D in manufacturing - verifying that production meets declared vapour transmission performance.
- Guide designers and specifiers (mechanical engineers, HVAC designers, insulation contractors) in choosing materials for hot/cold pipework and industrial installations where moisture control is critical.
Who should use this standard
- Insulation manufacturers and product testing laboratories
- Building services engineers, HVAC and mechanical designers
- Specifiers, procurement teams and certification bodies
- Research and development teams working on thermal insulation materials
Related standards (normative references)
- ISO 9346 - Hygrothermal terminology for mass transfer
- ISO 12628 - Dimensions and squareness of preformed pipe insulation
- ISO 29768 - Determination of linear dimensions of test specimens
This standard ensures consistent, repeatable measurement of water vapour transmission properties for preformed pipe insulation, enabling reliable product comparison, compliance and moisture‑management decisions in building and industrial applications.
