ISO 10468:2023

Overview

ISO 10468:2023 defines standardized methods to determine the ring creep properties of glass‑reinforced thermosetting plastics (GRP pipes) under wet or dry conditions. The standard specifies how to measure the creep factor and the long‑term ring creep stiffness by loading a pipe ring in compression, monitoring vertical deflection over time, and extrapolating long‑term behaviour. Dry testing is used primarily for raw‑material consistency and quality control; wet testing simulates in‑service, immersed conditions.

Key topics and requirements

• Test principle: A cut pipe ring is supported horizontally and compressed diametrically under a constant vertical force; vertical deflection is recorded at intervals and long‑term stiffness is extrapolated.
• Measured properties: Initial ring stiffness, long‑term ring creep stiffness (at a reference position) and the creep factor (ratio of long‑term to initial stiffness).
• Apparatus:
  • Compressive loading machine capable of maintaining constant force within ±1%.
  • Force application via bearing plates (width ≥ 100 mm) or beam bars (flat face width 15–55 mm); the same arrangement must be used for initial and long‑term tests.
  • For wet tests: water container with tap water pH 7 ± 2 kept at the specified temperature; ensure buoyancy does not affect applied force.
• Measuring accuracy:
  • Dimensional devices: calibrated to ±1% of dimension.
  • Deflection devices: calibrated to ±1% of initial deflection value.
  • Load measurement: ±1% accuracy.
• Test pieces: Complete ring; default length (if not specified by referring standard) 300 ± 15 mm.
• Procedure notes:
  • Conditioning, test temperature, strain level, extrapolation time and test piece length are set by the referring standard.
  • Initial ring stiffness may be measured by constant load or constant deflection (aligned with ISO 7685).
  • Results reported include stiffness/deflection versus time and calculated creep factor (average of two rings).

Applications

• Quality control and batch consistency testing for GRP pipe manufacturers.
• Long‑term performance assessment for designers and specifiers of buried or submerged piping systems.
• Product validation, regulatory compliance and certification testing laboratories.
• R&D for material formulation and laminate design to reduce creep under service loads.

Who uses it: GRP pipe manufacturers, materials engineers, test laboratories, infrastructure specifiers, certification bodies.

Related standards

• ISO 7685 - Determination of initial ring stiffness for GRP pipes.
• ISO 3126 - Dimensional determination for plastics piping components.
• ISO 10928:2016 - Regression methods and their use for GRP pipe testing.

Keywords: ISO 10468:2023, GRP pipes, ring creep, creep factor, long‑term creep stiffness, wet creep testing, dry creep testing, ring stiffness, pipe testing.