ASTM D56-22 is a standard test method for determining the flash point of liquids using a Tag closed cup flashpoint tester. It is suitable for liquid samples with a flash point below 93 ° C (200 ° F). The standard specifies in detail the test equipment, sample preparation, test procedures and method for calculating results to ensure the accuracy and repeatability of test results. Flash point refers to the minimum temperature at which a liquid releases enough vapor to form a flammable mixture with air under specific conditions. It is an important indicator for evaluating the flammability and safety of liquids. ASTM D56-22 is suitable for quality control and security evaluation of petroleum products, solvents and Miscellaneous volatile liquids. It is widely used in chemical, petroleum and transportation fields.