Overview
ISO 12623:2022 specifies a standard test method for determining the short-term water absorption of preformed pipe insulation by partial immersion. Intended to simulate the effect of rain exposure during installation (24 h), the standard applies to thermal insulating products used for building equipment and industrial installations, but can also be used for other applications. The standard replaces and merges earlier EN/ISO guidance and updates procedures, specimen preparation and reporting requirements.
Key topics and technical requirements
- Scope and principle: Measures short-term water uptake by recording the change in mass of a test specimen after 24 hours partial immersion; results reported as water absorption per unit immersed surface (kg/m²).
- Test methods: Two alternative procedures are defined:
- Method A (drainage) - specimens drained for a specified time before weighing after 24 h.
- Method B (deduction of initial water uptake) - initial short contact is measured and deducted; applicable only when initial uptake is within specified limits.
- Apparatus and conditions:
- Precision balance (0.1 g or 0.5%).
- Water tank with level control (±2 mm) and specimen support to maintain original shape and ≥85% contact area.
- Tap water at (23 ± 5) °C (tropical alternative: 27 ± 5 °C).
- Test specimens:
- Prepared without reducing original thickness; retain skins/coatings.
- Size rules depending on outside diameter (≤300 mm or >300 mm) and specimen length chosen so immersed cylindrical surface area ≈ 40 000 mm².
- Conditioning: at least 6 h at (23 ± 5) °C (stricter conditioning for disputes).
- Calculation and reporting:
- Water absorption W = mass change ÷ immersed surface area (rounded to 0.01 kg/m²).
- Immersed area A is calculated from specimen geometry (arc/cosine-based formula).
- Test report must reference ISO 12623:2022 and include test conditions, specimen details and results.
Applications
- Quality control and batch testing of preformed pipe insulation.
- Product development and material comparison to assess water uptake, durability and suitability for outdoor/installation exposure.
- Specification and acceptance testing in building services, HVAC, plumbing and industrial piping projects where short-term rain exposure during installation is a concern.
- Laboratory accreditation and compliance testing for manufacturers and independent test houses.
Who should use this standard
- Insulation manufacturers and R&D teams
- Third‑party testing laboratories and certification bodies
- Specifiers, consultants and contractors in HVAC/building services
- Procurement and quality assurance teams requiring objective water-absorption data
Related standards
- ISO 12628 - dimensions and geometry of preformed pipe insulation (referenced for specimen measurement)
- ISO 29767 - tests on flat products for comparison when pipe insulation is cut from flat material
- Note: ISO 12623:2022 merged content from earlier EN 13472 and the 2011 edition of ISO 12623.
Keywords: ISO 12623:2022, short-term water absorption, preformed pipe insulation, thermal insulating products, partial immersion test, water uptake, Method A, Method B.