ASTM D56-16 pdf free download. Standard Test Method for Flash Point by Tag Closed Cup Tester.
To ensure an acceptable precision, this dynamic flash point test method employs a prescribed rate of’ temperature rise for the material under test. The rate of heating may not in all cases give the precision quoted in the test method because of the low thermal conductivity of certain materials. To improve the prediction of flammability, Test Method D394 I, which utiliies a sloer heating rate, was developed. Test Method 1)3941 provides conditions closer to equilibrium where the vapor above the liquid and the liquid are at about the same temperature. If a specification requires Test Method D56. do not change to Test Method 1)3941 or other test method without permission from the specifIer.
Flash point values are a function of the apparatus design. the condition of the apparatus used, and the operational procedure carried out. Flash point can ihereflre only be defined in terms of a sandard test method, and no general valid correlation can be guaranteed between results obtained by ditkrent test methods, or with test apparatus ditierent from that specified.
ASTM D56-16 covers the determination of the flash point, by tag manual and automated closed testers, of liquids with a viscosity below 5.5 mm2/s (cSt) at 40 °C (104 °F), or below 9.5 mm2/s (cSt) at 25 °C (77 °F), and a flash point below 93 °C (200 °F).
4. Summary of rflst Method
4.1 The specimen is placed in the cup of the tester and. with the lid closed, heated at a slow constant rate. An ignition source is directed into the cup at regular intervals. The flash point is taken as the lowest temperature at which application ot the ignition source causes the vapor above the specimen to ignitc.
5. Significance and Use
5.1 Flash point measures the tendency of the specimen to form a flammable mixture with air under controlled laboratory conditions. It is only one of a number of properties that shall he considered in assessing the overall flammability haiard of a material.
5.2 Flash point is used in shipping and safety regulations to define flammable and combustible materials. One should consult the particular regulation involved for precise definitions of these classes.
5.3 Flash point can indicate the possible presence of highly volatile and flammable materials in a relatively nonvolatile or nonflammable material. For example. an abnormally low flash point on a sample of kerosene can indicate gasoline contamination.ASTM D56-16 pdf download.