ISO 6259-3:2015

Overview

ISO 6259-3:2015 - "Thermoplastics pipes - Determination of tensile properties - Part 3: Polyolefin pipes" specifies a standardized method for measuring tensile behaviour of polyolefin pipes. It covers polyethylene (PE), cross‑linked polyethylene (XLPE), polypropylene (PP) and polybutene (PB) pipe materials and defines how to determine the stress at yield and elongation at break of pipe‑form test pieces. The part supplements the general rules in ISO 6259‑1 and is aligned with ISO 527 principles for tensile testing.

Key Topics

• Scope and materials: Applies to polyolefin pipes - PE, XLPE, PP, PB - for tensile property determination.
• Properties measured: Stress at yield and elongation at break (expressed per ISO 6259‑1 test conditions).
• Test piece selection & preparation:
  • Test pieces obtained by die cutting (preferred for thin walls ≤12 mm) or machining (preferred for thicker walls).
  • Three specimen types (Type 1, Type 2, Type 3) are defined; selection depends on nominal wall thickness.
  • Typical gauge lengths: Type 1 = 50 mm, Type 2 = 25 mm, Type 3 = 20 mm.
• Wall‑thickness guidance (selection from Table 4):
  • e ≤ 5 mm → Type 2
  • 5 < e ≤ 12 mm → Type 1
  • 12 < e ≤ 25 mm → Type 1 or Type 3
  • e > 25 mm → Type 3
• Test speed (examples from Table 5):
  • e ≤ 5 mm (Type 2): 100 mm/min
  • 5 < e ≤ 12 mm (Type 1): 50 mm/min
  • 12 < e ≤ 25 mm (Type 1): 25 mm/min (Type 3 alternatives may use 10 mm/min)
  • e > 25 mm (Type 3): 10 mm/min
• Reporting & conditioning: Test procedure, apparatus and conditioning reference ISO 6259‑1; results expression and test report requirements are aligned with ISO 6259‑1.

Applications

• Quality control in polyolefin pipe manufacturing to verify material/process consistency.
• Product development and R&D to compare material grades or processing routes.
• Specification and compliance: Useful for procurement specs, material acceptance tests and regulatory submissions where tensile properties of pipes are required.
• Failure analysis and lab testing for forensic evaluation of pipes under tensile loading.

Who uses it: pipe manufacturers, materials engineers, test laboratories, standards writers, consultants, and regulatory bodies.

Related Standards

• ISO 6259‑1:2015 - Thermoplastics pipes - Determination of tensile properties - Part 1: General test method (procedures, apparatus, conditioning)
• ISO 527 series - Plastics - Determination of tensile properties (general principles)
• ISO 6259 (other parts) - Part 1 (general) and Part 2 (PVC pipes)

Note: Informative annexes provide recommended basic elongation values: PE & XLPE ≥ 350%, PP ≥ 200%, PB (≤5 mm) ≥ 125% (as guidance only).