ISO 13259:2020

Overview

ISO 13259:2020 specifies a laboratory test method for assessing the leaktightness of elastomeric sealing‑ring joints used in buried thermoplastics piping systems for underground non‑pressure applications (soil, waste and drainage). The standard defines test pressures, deflection conditions and the assembly/apparatus requirements to simulate real‑world loading (settlement, angular misalignment, deformation) and to detect leakage under controlled vacuum and hydrostatic conditions.

Key topics and technical requirements

• Test sequence: each test piece is subjected sequentially to three basic pressures:
  • p1 - internal negative air pressure (partial vacuum) (default −0.3 bar ±5%) to check for air tightness and vacuum loss;
  • p2 - low internal hydrostatic pressure (default 0.05 bar ±10%);
  • p3 - higher internal hydrostatic pressure (default 0.5 bar to 0.55 bar).
• Deflection conditions: four defined conditions determine joint loading:
  • Condition A - no additional deflection;
  • Condition B - diametric deflection;
  • Condition C - angular deflection;
  • Condition D - simultaneous angular and diametric deflection.
• Angular deflection values (α) depend on pipe diameter (d): 2° for d ≤ 315 mm, 1.5° for 315 < d ≤ 630 mm, 1° for d > 630 mm (tolerance +0.2°).
• Apparatus and fixtures: jig capable of applying specified diametric and angular deflections, pressure/vacuum sources, venting and measurement devices; loading beams and clamps sized according to pipe diameter to avoid unintended support.
• Test conditions and durations: stabilization and monitoring periods (e.g., minimum 5–15 minutes per pressure step), water filling and venting requirements, and temperature control (ambient; in dispute use 23 ± 5 °C; vacuum tests require ≤2 °C variation).
• Test pieces: assembled per manufacturer’s instructions; same assembly used throughout the test regime; internal mandrels allowed to reduce water volume if they do not support deformation.

Practical applications

• Verifying watertightness of elastomeric sealing‑ring joints against infiltration/exfiltration in buried stormwater, sewer and drainage systems.
• Simulating soil settlement and angular misalignment to evaluate joint performance under field‑like deformations.
• Supporting type testing, product development, quality control and certification for thermoplastic pipe systems used in non‑pressure underground installations.

Who should use this standard

• Pipe and fitting manufacturers and R&D teams
• Independent test laboratories and conformity assessment bodies
• Specification writers, public works engineers and procurement authorities
• Certification schemes and regulatory authorities for underground drainage systems

Related notes

• ISO 13259:2020 was prepared by ISO/TC 138 (Plastic pipes) in cooperation with CEN/TC 155. Selection of specific test pressures, deflection magnitudes and acceptance criteria is typically set in the referring product standard. Keywords: ISO 13259:2020, thermoplastics piping, leaktightness test, elastomeric sealing ring, underground non‑pressure applications.