ISO 15853:1999

Overview

ISO 15853:1999 specifies a reproducible procedure for producing tubular test pieces by injection moulding of thermoplastic materials intended for piping components, to determine their hydrostatic (internal pressure) resistance. The standard defines mould design, moulding machine capabilities and process controls so that injection‑moulded tubular specimens can be tested under the same methods applied to extruded pipes for long‑term hydrostatic strength assessment.

Key topics and requirements

• Specimen geometry and limits: nominal outside diameter between 25 mm and 110 mm; free length generally 3 × d (with a 140 mm minimum for d = 50 mm). Injection‑moulded pieces shall have one end closed.
• Mould design: single‑cavity, end‑gated mould with sprue diameter ≥ 5 mm. Heat‑transfer system must keep temperature differences on the cavity surface below 5 °C.
• Injection‑moulding equipment & controls: use automatic reciprocating‑screw machines with sufficient clamping force and appropriate screw dimensions. Control tolerances include injection pressure ±3%, injection time ±0.05 s, melt temperature ±3 °C, mould temperature ±3 °C (up to 80 °C), shot mass ±1%, and other limits specified in the standard.
• Process and quality checks: condition material if needed; run to steady‑state then collect parts. Maintain low injection velocity for thin‑walled, high length:diameter tubes. Verify no sink marks, voids or excessive flash. Check for thermal degradation (melt flow rate, K‑value) where applicable.
• Recorded data & traceability: the production report must document material, conditioning, moulding machine, detailed moulding conditions (melt/mould temperatures, injection/hold times and pressures, cycle time, shot mass), dimensions, appearance, oven and crushing test results, and production date.
• Acceptance checks: visual appearance, dimensional tolerances per ISO 3126, oven test (ISO 580) and crushing test (ISO 9853) as applicable.

Applications and users

ISO 15853 is practical for:

• Materials engineers and R&D teams validating compound formulations for injection‑moulded fittings and valve bodies.
• Quality control and test laboratories preparing specimens for hydrostatic pressure testing (ISO 1167) and long‑term extrapolation methods (e.g., ISO 9080) to determine MRS and material classification (ISO 12162).
• Manufacturers of piping components who need to prove time‑related hydrostatic performance of injection‑moulded parts under reproducible, pipe‑equivalent conditions.
• Certification bodies and standards compliance auditors assessing traceable specimen production and process control records.

Related standards

• ISO 1167 - Resistance to internal pressure (hydrostatic tests)
• ISO 9080 - Long‑term hydrostatic strength extrapolation
• ISO 12162 - MRS and material classification
• ISO 3126, ISO 580, ISO 9853, ISO 294‑1 - referenced for dimensions, oven/crushing tests and injection‑moulding principles

ISO 15853 helps ensure that injection‑moulded tubular test pieces are produced consistently so hydrostatic strength test results are reliable, comparable and suitable for long‑term performance assessment of thermoplastic piping materials.