The significance of determining the flash point of oil products

1, Core significance: Security risk prevention and control (the most critical role)
The flash point is the critical indicator of the flammability of oil products (referring to the lowest temperature at which oil vapor can briefly flash when exposed to a fire source after forming a combustible mixture with air), which directly determines the fire and explosion risk level of oil products:
Classification of hazardous chemicals:
Flash point<28 ℃: Class A flammable liquids (such as gasoline and benzene) have extremely high fire hazards and require special storage (explosion-proof warehouses, anti-static facilities) and transportation (specialized dangerous goods vehicles);
28 ℃ ≤ Flash point ＜ 60 ℃: Class B flammable liquids (such as kerosene and diesel (partially)) should be stored in limited quantities and kept away from sources of ignition;
Flash point ≥ 60 ℃: Class C flammable liquids (such as heavy oil and lubricating oil) have low fire risk, but fire prevention measures are still required.
(According to GB 30000.7-2013 "Specification for Classification and Labelling of Chemicals Part 7: Flammable Liquids")
Guidance on storage and transportation safety:
The storage environment temperature should be 10-15 ℃ lower than the flash point (to avoid the formation of flammable vapors due to oil evaporation);
Limit the ventilation of the storage tank and install flame arresters to prevent external sources from igniting the vapor inside the tank;
Avoid severe impact during transportation and use anti-static grounding to prevent static sparks from causing flash ignition.
Preventing fires during use:
Industrial scenarios (such as boiler combustion, mechanical lubrication): If the flash point of the oil is too low, it is easy to evaporate and form flammable mixtures on the surface of high-temperature equipment, which can cause fires when exposed to high temperatures or sparks;
Vehicle scenarios (such as diesel engines): A low flash point may cause fuel system leaks and fires, while a high flash point may affect atomization combustion efficiency.
2, Quality identification: determining the purity and degree of deterioration of oil products
Identify whether the oil products are mixed or contaminated:
The flash point of pure oil products is a fixed value (such as the flash point of 92 # gasoline is about -50 ℃, and the flash point of 0 # diesel is about 55 ℃); If the flash point drops abnormally, it may be due to the mixing of high volatile oil products (such as gasoline mixed with diesel); If the flash point increases, it may be due to the mixing of high boiling point impurities (such as asphalt mixed in lubricating oil).
Example: If fuel is mixed into lubricating oil during use (such as engine oil dilution), the flash point will significantly decrease, and it needs to be replaced in a timely manner, otherwise it may cause engine fire.
Assess the degree of oil aging or oxidation:
Oil products (especially lubricating oil and hydraulic oil) will gradually oxidize when used in high temperature and oxygen environments, producing heavy products such as gum and asphaltene, leading to an increase in flash point;
If the flash point changes beyond the standard limit (such as an increase of ≥ 10 ℃), it indicates that the oil has deteriorated and needs to be replaced to avoid equipment wear and system blockage.
3, Application selection: Match working condition requirements to ensure equipment reliability
There are clear requirements for the flash point of oil products in different scenarios, and improper selection can lead to equipment failure or safety hazards:
Fuel oil selection:
Internal combustion engine (gasoline engine): requires low flash point oil products (such as gasoline flash point<0 ℃) to ensure easy volatilization and formation of flammable mixtures at low temperatures, achieving rapid ignition;
Boiler and kiln combustion: Medium to high flash point fuel oil (such as heavy oil with a flash point ≥ 100 ℃) is required to avoid unstable flames caused by rapid evaporation of the oil during the combustion process, or to prevent fires caused by leaks.
Lubricating oil/hydraulic oil selection:
High temperature conditions (such as aviation engines and metallurgical equipment): High flash point oils (such as synthetic lubricants with a flash point ≥ 200 ℃) are required to prevent the oils from evaporating too quickly at high temperatures, leading to lubrication failure or the production of flammable vapors;
Low temperature conditions (such as outdoor equipment in the north): Oil products with moderate flash points are required to avoid poor low-temperature fluidity caused by excessively high flash points, which may affect lubrication effectiveness.
Special scenario requirements:
Explosion proof environments such as coal mines and underground mines require the use of specialized oil products with high flash points (≥ 120 ℃) and no explosiveness to prevent oil products from igniting at high temperatures.
4, Process monitoring: guide the production and refining process of oil products
Quality control in the production process:
In oil refining (such as distillation and hydrogenation), process parameters (such as distillation temperature and tower top pressure) are adjusted by monitoring the flash point to ensure that the product meets standards (such as diesel flash point needs to be controlled at 55-70 ℃);
When blending oil products, adjust the proportion of different components to achieve the target flash point of the final product (such as when blending diesel, adjust the flash point to the qualified range by mixing high flash point components).
Validation of refining process effect:
After refining processes such as dewaxing, degumming, and desulfurization of oil products, the flash point is a key indicator for verifying the refining effect; If the flash point does not meet the standard after refining, it indicates that impurities have not been completely removed and need to be refined again.