ISO 10146:2019 PDF

Overview

ISO 10146:2019 defines how to determine the expected strength of pipes made from crosslinked polyethylene (PE‑X) and crosslinked medium density polyethylene (PE‑MDX) as a function of time and temperature. The standard supplies reference lines (mathematical equations, graphs and tables) giving minimum long‑term hydrostatic strength for use in design calculations and lifetime assessments of PE‑X and PE‑MDX piping systems. It applies to pipes meeting the minimum degree of crosslinking specified in Clause 4 and to PE‑MDX within the density range 926–940 kg/m3 (per ISO 17855‑1:2014).

Key topics and technical requirements

• Reference lines and formulae: The standard provides analytical reference lines for temperatures between 20 °C and 95 °C and separate expressions for 110 °C. These describe log(time) as a function of temperature (K) and hoop stress (MPa), enabling interpolation and controlled extrapolation.
• Degree of crosslinking: Minimum crosslinking after production is required and quantified by gel content (ISO 10147). Typical minimums: peroxide and UV processes ≥70%, silane ≥65%, electron beam ≥60%.
• Extrapolation and activation energy: Temperature dependence is based on an Arrhenius approach with an activation energy of 110 kJ/mol. The standard lists extrapolation factors (k) to convert life at 110 °C to lower temperatures (e.g., k ≈ 4 at ≤95 °C, k ≈ 18 at ≤80 °C, k ≈ 50 at ≤70 °C, k ≈ 100 for