Overview
ISO 2507-2:1995 - Thermoplastics pipes and fittings - Vicat softening temperature - Part 2 specifies the particular test conditions for determining the Vicat softening temperature (VST) of PVC materials used in pipes and fittings. It applies to unplasticized poly(vinyl chloride) (PVC-U), chlorinated poly(vinyl chloride) (PVC-C) and high impact resistance poly(vinyl chloride) (PVC-HI) pipes and fittings. The general test method is given in ISO 2507-1:1995; this Part 2 adds material‑specific conditions and informative basic VST specifications.
Key Topics and Requirements
- Purpose: define test conditions to determine the Vicat softening temperature for PVC-U, PVC-C and PVC-HI pipework components.
- Normative reference: relies on the general procedure, apparatus, specimen preparation, conditioning, procedure and reporting defined in ISO 2507-1.
- Material scope:
- PVC-U (pipes and moulded fittings)
- PVC-C (pressure and non‑pressure pipes and fittings)
- PVC-HI (high impact resistance pipes)
- Informative basic VST specifications (given in annexes A–C):
- PVC-U pipes: not less than 79 °C
- PVC-U moulded fittings: not less than 77 °C
- PVC-C pressure pipes: not less than 110 °C
- PVC-C fittings: not less than 103 °C
- PVC-C non‑pressure pipes: not less than 90 °C
- PVC-HI pipes: not less than 76 °C
- Annexes A, B and C provide basic specification values for information; product standards may specify more stringent limits for particular applications.
Applications and Who Uses It
- Manufacturers of PVC-U, PVC-C and PVC-HI pipes and fittings use ISO 2507-2 for product testing and quality control to demonstrate temperature performance.
- Test laboratories and certification bodies apply the specified test conditions when reporting Vicat softening temperature for compliance and labeling.
- Engineers, specifiers and procurement professionals use VST data to select pipe materials for temperature-critical fluid transport systems (e.g., hot water, industrial services).
- Regulators and standards committees reference these test conditions when developing or harmonizing product standards and safety requirements.
Related Standards
- ISO 2507-1:1995 - Thermoplastics pipes and fittings - Vicat softening temperature - Part 1: General test method (primary reference for apparatus and procedure).
- ISO 2507 series includes Part 3 for ABS and ASA materials (material‑specific test conditions for other thermoplastics).
Keywords: ISO 2507-2:1995, Vicat softening temperature, PVC-U, PVC-C, PVC-HI, thermoplastics pipes, test conditions, pipe fittings, VST, material specification.
