ISO 9852:2007

Overview

ISO 9852:2007 specifies a standardized test method - Dichloromethane Resistance at a Specified Temperature (DCMT) - to determine the resistance of unplasticized poly(vinyl chloride) (PVC‑U) pipes to dichloromethane. Applicable to all PVC‑U pipes regardless of intended use, the method is designed for rapid quality control during manufacture and gives an indication of material gelation and long‑term performance.

Key topics and requirements

• Test principle: Immerse a chamfered pipe test piece in dichloromethane at a specified temperature T for (30 ± 1) minutes, then allow dripping in a water layer before drying and inspection.
• Test pieces: Cut to 160 mm length; typically three pieces unless the referring standard specifies otherwise. Chamfer one end according to wall thickness:
  • e < 8 mm → chamfer 10°
  • 8 ≤ e < 16 mm → chamfer 20°
  • e ≥ 16 mm → chamfer 30°
• Immersion and containment: Dichloromethane depth must fully cover the chamfered zone and be covered by a water layer (preferably 250–300 mm, minimum 20 mm) to reduce evaporation and capture drips.
• Temperature control: Maintain dichloromethane at (T ± 0.5) °C; the test temperature shall not be less than 12 °C (T is set by the referring standard).
• Apparatus and safety: Use a glass or stainless‑steel container with grating and lid, cooling equipment, stirrer and a hood with fume extraction. Dichloromethane is volatile and hazardous (boiling point ~40 °C); ensure ventilation and PPE. The specified maximum admissible concentration (MAC/TLV) is noted in the standard.
• Measurement and results: Inspect for signs of attack (whitening, precipitation, or material loss). Express outcomes as “No attack” or “Attacked”; Annex A provides optional guidance to quantify attack as percentage of chamfer surface.
• Quality controls: Monitor dichloromethane refractive index (variation ≤ ±0.002) and replenish bath between tests as needed.

Applications and who uses it

• PVC‑U pipe manufacturers for in‑line quality control and batch acceptance.
• Test laboratories and material engineers assessing gelation quality and predicting long‑term performance.
• Certification bodies and product compliance teams validating pipe resistance to solvents.
• R&D teams comparing formulations or processing conditions that affect PVC‑U resistance.

Related standards

• The 2007 edition aligns with EN 580:2003 (noted in the foreword). ISO 9852 is produced by ISO/TC 138 (Plastics pipes, fittings and valves). The referring standard specifies the test temperature T and other acceptance criteria.

Keywords: ISO 9852:2007, PVC‑U pipes, dichloromethane resistance, DCMT test method, pipe testing, quality control, solvent resistance, ISO standard.