Overview
ISO 13267:2022 specifies test methods for buckling resistance of thermoplastics inspection chamber and manhole bases used in non‑pressure underground drainage and sewerage systems. The standard defines how to assess the resistance of chamber/manhole bases to external soil and ground‑water pressure after installation, using either internal negative pressure or external hydrostatic pressure tests.
Key topics and requirements
- Test principle: sealed test assembly (base ± riser ≥ 300 mm above main channel) is exposed to a constant internal negative pressure or an equivalent positive external hydrostatic pressure while embedded in backfill or submerged in a water tank.
- Test configurations:
- Free‑standing internal negative pressure test
- Internal negative pressure test in a test box with granular bed and backfill
- External pressure test with assembly submerged in a sealed water tank
- Apparatus & instrumentation: test box or sealable tank, granular bed/backfill (per CEN/TS 1046), end closures, pressure/vacuum source, pressure gauges (±2% accuracy), thermometer (±0.5 °C), optional deflection measurement (±0.1 mm).
- Environmental & conditioning requirements: tests generally at 15–25 °C; water temperature for submerged tests (20 ± 2) °C unless otherwise stated; test pieces tested no less than 21 days after manufacture and conditioned in air ≥ 6 h at 15–25 °C.
- Duration & tolerances: typical minimum duration given is 1 008 hours (or as specified by the referring product standard); pressures and durations maintained within ±2% tolerance.
- Evaluation: visual inspection for cracking and defects; optional time–deflection data can be extrapolated (50‑year prediction) using least‑squares method generally as described in ISO 9967.
- Reporting: test report must reference ISO 13267:2022, identify the product and nominal sizes, list soil/backfill type, applied pressure, temperature, duration, deflections or predicted 50‑year deflections, visible cracks, and any deviations or unusual observations.
Practical applications
- Product performance verification and type testing for thermoplastic manhole and inspection chamber bases.
- Quality assurance for manufacturers and third‑party testing laboratories.
- Input for standards compliance, procurement specifications and regulatory acceptance of underground drainage components.
- R&D and design validation to compare buckling resistance across materials, wall constructions (single/double wall), and backfill conditions.
Who should use this standard
- Manufacturers of thermoplastic inspection chambers and manhole bases
- Independent test laboratories and materials testing facilities
- Civil and sanitary engineers specifying drainage/sewerage components
- Certification bodies, regulatory agencies and procurement teams
Related standards
- ISO 9967:2016 - Thermoplastics pipes - Determination of creep ratio (used for deflection extrapolation)
- CEN/TS 1046:2021 - Trench installation and backfill requirements for thermoplastics systems
Keywords: ISO 13267:2022, thermoplastics inspection chamber and manhole bases, buckling resistance test methods, non‑pressure underground drainage, external soil pressure, internal negative pressure, deflection measurement, test box, water tank.
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