Overview
ISO 2160:1998 defines the copper strip test for assessing the corrosiveness to copper of liquid petroleum products and certain solvents. Published by ISO (third edition, 1998), the standard describes sample preparation, required apparatus, test procedures (including pressure‑vessel testing for volatile fuels), and a visual classification system for copper tarnish and corrosion. It is a routine quality and compatibility test used in fuel and lubricant testing laboratories.
Keywords: ISO 2160, copper strip test, petroleum products, corrosiveness to copper, fuel testing, copper corrosion.
Key topics and technical requirements
- Scope: Applies to liquid petroleum products and certain solvents; volatile products up to a vapour pressure of 124 kPa at 37.8 °C are included. Aviation fuels and some gasolines require pressure‑vessel testing.
- Principle: A polished copper strip is immersed in a 30 ml test portion and heated under specified temperature/time; after exposure the strip is washed, dried and compared visually with corrosion standards.
- Test specimen:
- Copper strips: electrolytic copper >99.9% purity; nominal 75 mm × 12.5 mm, thickness 1.5–3.0 mm.
- Test portion: nominal 30 ml in a clean 25 × 150 mm borosilicate tube (ensure ≥5 mm headspace above strip).
- Reagents and apparatus:
- Wash solvent: 2,2,4‑trimethylpentane (isooctane) min. 99.75% or equivalent sulfur‑free hydrocarbon.
- Pressure vessel: stainless steel capable of 700 kPa gauge for aviation fuel tests.
- Temperature control baths, polishing materials, forceps, viewing tubes and corrosion standards.
- Procedures:
- Polishing and final preparation of copper strips to a consistent finish.
- Pressure vessel procedure (e.g., aviation fuels at ~100 °C) and atmospheric test tube procedures (e.g., 40–100 °C depending on product class).
- Visual assessment against calibrated classification levels (Class 1: slight tarnish through Class 4: corrosion/black).
- Reporting: Results expressed as: “Corrosion copper strip (X h/Y °C), Class Z” and include test details and any deviations.
Applications and practical value
- Routine quality control of fuels, solvents and petroleum products.
- Compatibility testing for storage tanks, piping and components made of copper or copper alloys.
- Acceptance testing for aviation fuels, motor gasolines and industrial solvents.
- Support for product specifications, supplier qualification, additive evaluation and failure analysis.
Who uses this standard?
- Petrochemical and refinery laboratories
- Third‑party fuel testing and certification laboratories
- Aviation fuel quality/control teams and maintenance organizations
- Additive manufacturers, materials engineers, and standards bodies
Related standards
- ISO 3170 / ISO 3171 - sampling of petroleum liquids (normative references in ISO 2160)
- ISO 6251 - testing for higher‑vapour‑pressure volatile products (see caution for volatile samples)
ISO 2160 provides a simple, standardized visual method to identify copper‑corrosive constituents in fuels and solvents, helping organizations control product quality and equipment compatibility.