Flash Point Measurement: Online Flash Point Analyzer
Online flash point measurement in refinery product streams: ATEX-compliant process flash point analyzer for diesel and similar products.
What is flash point and why is it measured?
Flash point is the lowest temperature at which the vapor of a liquid petroleum product reaches a concentration that can flash on contact with an ignition source. It determines how the product is classified for fire and storage safety, and it is one of the specification parameters of products such as diesel, kerosene and jet fuel. In refineries, light components that lower the flash point mixing into a product cause quality deviation; continuous flash point monitoring on column side draws and product lines therefore allows quick column adjustment.
Where is flash point measured?
- Distillation column side draws: In diesel, kerosene and similar product streams.
- Product and blending lines: In quality control.
- Pre-storage lines: In verifying shipment quality.
How is flash point measured?
An online flash point analyzer automates the laboratory method: a sample taken from the process line is heated in a controlled manner, an ignition source is applied at set temperature intervals, and the temperature at which a flash occurs is determined. The analyzer repeats the measurement cycle, updates the result periodically and sends the value to the process control system. The instrument can be supplied with a sample preparation system and hazardous area certification (ATEX/IECEx Zone 1), which is important for refinery installations.
The online result is verified by periodic comparison with the laboratory method; this comparison is especially important when a product is run close to its specification limits.
Choosing a flash point analyzer
- Product type and expected flash point range
- Sampling, filter and conditioning requirements
- Hazardous area certification
- Plan for periodic comparison with laboratory results
Flash point measurement with Tetra
Tetra supplies the Icon Scientific Fp online flash point analyzer and carries out sample system and ATEX cabinet integration. Installation, commissioning, calibration and service are provided in Türkiye by Tetra.
Frequently asked questions
Which methods are used to measure flash point in the laboratory?
For products such as diesel, the Pensky-Martens closed cup method (ASTM D93) is common. Abel or Tag closed cup methods are used for kerosene and jet fuel, and the Cleveland open cup method (ASTM D92) for lubricating oils. Because methods can give different results on the same sample, the laboratory method to which the online analyzer will be correlated should be defined from the start.
What is the difference between closed cup and open cup flash point?
In the closed cup method, vapor is held inside the cup, so the flash occurs at a lower temperature. In the open cup method, vapor disperses into the surroundings, so a higher flash point is generally obtained. Fuel specifications are mostly based on closed cup methods.
What factors disturb online flash point measurement?
Water in the sample can disturb vapor formation and the heating profile during measurement and give an incorrect result. Light components evaporating and being lost in the sample line make the flash point appear higher than it is. Filter clogging and fluctuations in sample flow also reduce measurement repeatability.
How often should a flash point analyzer be verified?
Verification frequency is determined by the manufacturer's recommendation and how close to the specification limit the product is made. Regularly comparing online results with laboratory results and checking with reference samples of known flash point are recommended. If a systematic difference is seen, the sample system and ignition assembly should be checked first.
Products measuring this parameter
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