Overview
EN ISO 9852:2017 / ISO 9852:2007 defines a standardized test method (DCMT) to determine the resistance of unplasticized poly(vinyl chloride) (PVC‑U pipes) to dichloromethane at a specified temperature. Adopted by CEN, this method is applicable to all PVC‑U pipes regardless of intended use and is intended as a rapid quality‑control test during manufacture. The test helps assess the level and homogeneity of PVC gelation, which relates to mechanical and long‑term pipe performance.
Key topics and technical requirements
- Principle: A chamfered test piece of PVC‑U pipe is immersed in dichloromethane for (30 ± 1) min at a temperature T specified by the referring standard to verify the absence of attack.
- Sample preparation:
- Test pieces are typically 160 mm long; number of pieces (commonly three) and minimum wall thickness are set by the referring standard.
- One end is chamfered; chamfer angle depends on wall thickness (specified in the standard).
- Large pieces may be cut longitudinally into sections (saw blade max width 2.5 mm).
- Immersion and apparatus:
- Use a small glass or stainless‑steel container with a grating and lid, temperature control and stirrer, and a fume‑hood with extraction.
- Dichloromethane layer covers chamfered zone; covered by a deeper water layer (preferably 250–300 mm, not less than 20 mm) to limit evaporation and allow dripping after immersion.
- Maintain dichloromethane temperature at (T ± 0.5) °C; the standard sets a minimum test temperature (not less than 12 °C).
- Refractive index of dichloromethane should be known and monitored.
- Safety:
- Dichloromethane has low boiling point and toxic vapour; ventilation, fume extraction and safe handling of contaminated test pieces are required.
- Results:
- Inspection for whitening, precipitate or other attack after controlled drying; optional descriptive reporting of attack (Annex A).
Applications
- Quality control during manufacture of PVC‑U pipes to confirm resistance to dichloromethane at a given temperature (DCMT).
- Material assessment: indication of gelation quality and homogeneity, which correlate with long‑term mechanical performance.
- Type testing and compliance when a referring product standard specifies a DCMT requirement.
Who uses this standard
- PVC‑U pipe manufacturers and production quality labs
- Independent testing laboratories and certification bodies
- Product specifiers, procurement engineers and regulators concerned with plastics pipe durability
- Standards committees and R&D teams evaluating PVC processing and formulation
Related standards
- EN ISO 9852:2017 is the CEN adoption of ISO 9852:2007 and supersedes EN 580:2003. The method is referenced by product‑specific PVC‑U pipe standards that define the test temperature, minimum wall thickness and acceptance criteria.
