Flash point is the lowest temperature at which the test flame causes the sample vapor to ignite and the flame to spread to the surface of the liquid under the specified test conditions. The burning point is the temperature at which the sample is heated up and can burn continuously for at least 5 seconds on the basis of the flash point. The flash point and the burning point are used to indicate whether there are highly volatile or flammable substances in relatively non-volatile or flammable substances. They are one of the important parameters for the transportation, storage, operation and safety management of petroleum products.
Differences between open cup flash point tester and closed cup flash point tester
1. Different uses
Open cup flash point tester is often used to test lubricating oil
Closed cup flash point tester is often used to test kerosene, diesel, transformer oil, etc.
2. Different experimental principles
Experimental principle of open cup flash point: The principle of open cup flash point test is to put the sample into the test cup to the specified mark. First, increase the temperature of the sample, then slowly increase the temperature, and when it approaches the flash point, increase the temperature at a constant rate. At the specified temperature interval, a small test flame passes through the test cup horizontally, and the temperature at which the vapor on the surface of the liquid is ignited by the test flame is used as the result of the open cup flash point test.
Experimental principle of closed cup flash point: When the concentration of the mixture of oil, gas and air on the oil surface increases, the temperature at which continuous combustion (to be continued for not less than 5 seconds) can be formed when encountering an open flame is called the ignition point. The ignition point is higher than the flash point. From the perspective of fire prevention, it is hoped that the flash point and ignition point of the oil are higher, and the difference between the two is larger. From the perspective of combustion, it is hoped that the flash point and ignition point are lower, and the difference between the two is as small as possible.
3. Different concepts of the two
Open flash point tester: The result measured by the specified open flash point tester is called the open flash point, expressed in °C.
Closed flash point tester: The result measured by the specified closed flash point tester is called the closed flash point, expressed in °C. It refers to the temperature when the vapor generated by the surface of a flammable liquid or solid is flashed under the action of the test flame in a stable air environment.