What Is The Degree Difference Between The Open Flash Point And The Closed Flash Point?

Generally speaking, the open flash point of the same oil product is about 10-30 ℃ higher than the closed flash point, but the specific difference may vary depending on the properties of the oil product.
1, Common rough range of differences
Typical difference between open flash point and closed flash point for different types of oil products:
Light petroleum products (gasoline, kerosene, light diesel, etc.): about 10-20 ℃
Heavy petroleum products (lubricating oil, heavy oil, etc.): about 20-30 ℃, sometimes even larger
2, Why is there such a difference
Closed flash point: The oil cup is sealed, and the oil and gas are not easily lost. When the concentration reaches a certain level, it will flash, so the temperature is lower.
Open flash point: The oil cup is open, making it easy for oil and gas to diffuse and requiring higher temperatures to accumulate to a flammable concentration, resulting in a higher flash point.