ISO 3007:1999

Overview

ISO 3007:1999 - Petroleum products and crude petroleum - Determination of vapour pressure - Reid method specifies the standardized laboratory procedure for measuring the Reid vapour pressure (RVP) of liquid petroleum products and volatile crude oils. The method applies to hydrocarbon-based fuels and to blends containing certain oxygenated compounds within defined maximum concentrations. The test establishes vapour pressure at 37.8 °C using a closed vapour/liquid chamber assembly and is widely used for fuel quality control, regulatory compliance and environmental assessments.

Key topics and technical requirements

• Scope and applicability
  • Intended for liquid petroleum products consisting essentially of hydrocarbons or containing allowed oxygenates within maximum limits (ethers with ≥5 C: ≤15% V/V; ethanol: ≤10% V/V; higher alcohols: ≤7% V/V).
  • Excludes blends containing methanol or oxygenates outside the stated limits (use a dry vapour-pressure method instead).
  • Not applicable to liquefied petroleum gas (see ISO 4256).
  • Can be applied to volatile crude petroleum with vapour pressure >10 kPa (precision not evaluated).
• Test principle
  • A chilled sample is placed in the liquid chamber and connected to a vapour chamber preheated to 37.8 °C. The assembled apparatus is equilibrated in a bath at 37.8 °C until pressure stabilizes; the stabilized reading (with any corrections) is reported as the Reid vapour pressure.
  • Note: RVP approximates the absolute vapour pressure at 37.8 °C but differs from true vapour pressure due to sample vaporization and presence of air/water vapor.
• Procedures and apparatus
  • Four procedures described: A and B (alternative apparatus for RVP up to 180 kPa), C (for RVP above 180 kPa), and D (for aviation gasolines around 50 kPa).
  • Annexes detail apparatus configurations and thermometer specifications.
• Sampling and handling
  • High sensitivity to evaporation; strict sample care required (referenced sampling standard ISO 3170).
  • Sample containers: typically 1 L filled to 70–80%; samples chilled to 0–1 °C before transfer.
• Safety
  • Standard includes a general warning: users must implement appropriate safety and health practices.

Applications and users

• Laboratories performing fuel quality control, research and development, and batch acceptance testing.
• Refineries and fuel producers monitoring gasoline vapour pressure for performance and seasonality.
• Aviation and automotive fuel engineers assessing volatility impacts on combustion, startability and vapor lock.
• Environmental and regulatory bodies using vapour pressure data for emissions, air quality, and transport safety rules.
• Operators managing transfer and storage operations where vapour pressure affects safety and equipment design.

Related standards

• ISO 3170 - Petroleum liquids: manual sampling (normative reference).
• ISO 4256 - Vapour pressure of liquefied petroleum gases (for LPG).
• Guidance on dry vapour-pressure methods for fuels with methanol or non‑covered oxygenates (as noted in ISO 3007).

Keywords: ISO 3007, Reid vapour pressure, RVP, vapour pressure determination, petroleum products, crude petroleum, gasoline vapour pressure, fuel testing, ISO standard.