How to ptroleum qality tsting euipment
Petroleum quality testing is of great technical, economic, safety, and environmental significance. It runs through the entire process of petroleum exploration, refining, storage & transportation, and end use.
· Ensuring product quality and performance
· Ensuring safety in production, storage, and transportation
· Promoting refinery process optimization and cost control
· Reducing environmental pollution and supporting sustainable development
· Supporting trade pricing and quality arbitration
The petroleum testing products we provide evaluate petroleum quality from four main dimensions: physical properties, chemical composition and impurities, combustion and energy performance, and safety characteristics.
Physical Properties of Petroleum
| Crude Oil Grade | API Range | Corresponding Density (60°F, g/cm³) | Characteristics |
| Ultra-light crude | API ≥ 40 | ρ ≤ 0.825 | Extremely rich in light fractions; highest value |
| Light crude | 31.1 ≤ API < 40 | 0.825–0.870 | Easy to process; high gasoline and diesel yields |
| Medium crude | 22.3 ≤ API < 31.1 | 0.870–0.920 | Can be processed by most refineries |
| Heavy crude | 10 ≤ API < 22.3 | 0.920–1.000 | High heavy fractions; requires deep processing |
| Extra-heavy crude | API < 10 | ρ > 1.000 | Heavier than water; high asphaltene content; low value |
| Oil Grade | 15 °C | 40 °C | 50 °C | 100 °C | Description |
| Light oil | 10 | 5 | 3.5 | 1.5 | Good fluidity; low temperature sensitivity |
| Medium oil | 50 | 20 | 15 | 5 | Moderate fluidity |
| Heavy oil | 500 | 100 | 50 | 10 | Poor flowability; heating required |
| Residual oil | 5000 | 1000 | 500 | 50 | Very high viscosity; heating required for pipeline transport |
Standard: ASTM D4007
Crude oil is typically traded on a net oil basis, which means the volume of water and sediment (BS&W) is deducted. The centrifuge test provides a rapid method to determine if the water content exceeds acceptable limits.
General Water Content Classifications:
Mainstream Quality Crude: 0.1% - 0.3%
Average Quality Crude: 0.3% - 0.5%
Some Heavy or Specific Crudes: ≤ 1.0%
1. Pour Point
Standard: ASTM D97
Definition: The highest temperature at which a petroleum sample, under specified conditions, is cooled and just ceases to flow.
2. Cloud Point
Standard: ASTM D2500
Definition: The highest temperature at which a petroleum sample, under specified conditions, is cooled and wax crystals begin to precipitate, causing the liquid to become visibly cloudy for the first time.
The total amount of heat released when a unit mass (or volume) of fuel is completely combusted and the combustion products (such as flue gas) are cooled back to the initial temperature.
Standard: ASTM D5865
Gross Heating Value (GHV) vs. Net Heating Value (NHV)
Gross Heating Value (GHV): A laboratory-measured value that includes the latent heat of condensation of water vapor.
Net Heating Value (NHV): A value used in engineering applications that excludes the latent heat of condensation of water vapor. It is typically 5%–10% lower than the gross heating value.
Flash Point vs. Fire Point
Flash Point: The temperature at which a petroleum product produces enough vapor to ignite momentarily when exposed to an ignition source, but does not sustain combustion.
Net Heating Value (NHV): A value used in engineering applications that excludes the latent heat of condensation of water vapor. It is typically 5%–10% lower than the gross heating value.
Petroleum flash point test methods are mainly divided into two categories: open cup methods and closed cup methods. The former simulates open or ventilated environments, while the latter simulates enclosed or restricted spaces.
1. Open Cup Flash Point
Standard: ASTM D92
2. Closed Cup Flash Point
Standard: ASTM D93
| Product Name | Typical Closed Cup Flash Point Range | Typical Open Cup Flash Point Range | Main Test Method | Hazard Classification |
| Automotive gasoline | −40 °C to −20 °C | Usually not tested | ASTM D3828 / D93 | Highly flammable liquid |
| Aviation kerosene | 38 °C to 66 °C | Usually not tested | ASTM D93 | Flammable liquid |
| Diesel (Grade 0) | ≥ 60 °C (national standard) | – | ASTM D93 | Flammable liquid |
| Household kerosene | ≥ 38 °C | – | ASTM D93 | Flammable liquid |
| Lubricating oil (SN 5W-30) | – | 220 °C to 240 °C | ASTM D92 | Combustible / low-flammability liquid |
| Heavy fuel oil (180 cSt) | ≥ 60 °C | 80 °C to 120 °C | ASTM D93 / D92 | Flammable to combustible liquid |
| Asphalt (bitumen) | Usually not tested | ≥ 230 °C | ASTM D92 | Combustible / low-flammability liquid |
