Standard Test Method for the Determination of Flash and Fire Points by Cleveland Open Cup Tester

This test method was adopted as a joint ASTM-IP standard in 1965. It describes the determination of the flash point and fire point of petroleum products by a manual Cleveland open cup apparatus or an automated Cleveland open cup apparatus. This test method is applicable to all petroleum products with flash points above 79 °C (175 °F) and below 400 °C (752 °F) except fuel oils.

 

Flash point is only one of several properties that should be considered in assessing the overall flammability hazard of a material. It is used in shipping and safety regulations to define flammable and combustible materials. Moreover, it indicates the possible presence of highly volatile and flammable materials in a relatively nonvolatile or nonflammable material. The fire point is one measure of the tendency of the test specimen to support combustion.

 

The precisions for fire point were not determined in the current inter laboratory program. Fire point is a parameter that is not commonly specified, although in some cases, knowledge of this flammability temperature may be desired. This standard test method may occasionally be specified for the determination of the fire point of a fuel oil. For the determination of the flash points of fuel oils, use Test Method D93. Test Method D93 should also be used when it is desired to determine the possible presence of small but significant concentrations of lower flash point substances that may escape detection by Test Method D92. Test Method D1310 can be employed if the flash point is known to be below 79 °C (175 °F).

 

Reagents required for testing is cleaning solvents, suitable technical grade solvent should be used capable of cleaning out the test specimen from the test cup and drying the test cup. Some commonly used solvents are toluene and acetone.

 

For the determination of flash and fire point approximately 70 mL of test specimen is filled into a test cup. Initially the test cup may be filled below the filling mark to allow for thermal expansion of the sample. The cup shall be made of brass or other non-rusting metal of equivalent heat conductivity. The cup may be equipped with a handle. Solid material shall not be added to the test cup. If the samples are solid or viscous, they shall be heated until they are fluid before being poured into the test cup; however, the temperature of the sample during heating shall not exceed 56 °C (100 °F) below the expected flash point. Light hydrocarbons may be present in the form of gases, such as propane or butane, and may not be detected by testing because of losses during sampling and filling of the test cup.

 

If the samples are containing dissolved or free water can be dehydrated with calcium chloride or by filtering through a qualitative filter paper or a loose plug of dry absorbent cotton to remove excess moisture content. After putting the sample into test cup, the temperature of the test specimen is increased rapidly at first and then at a slower constant rate as the flash point is approached. Heating Plate shall be of sufficient dimension and materials to ensure that thermal heat to the test cup is only applied to the bottom of the test cup and that extraneous heat to the test cup other than to the bottom is minimized. At specified intervals, a test flame is passed across the cup.

 

The flash point is the lowest liquid temperature at which application of the test flame causes the vapors of the test specimen of the sample to ignite. To determine the fire point, the test is continued until the application of the test flame causes the test specimen to ignite and sustain burning for a minimum of 5 s. Ignition Source Applicator have been used for applying the test flame may be of any suitable type. When using a test flame, it is suggested that the tip be 1.6 mm 6 0.05 mm (1⁄16 in.) in diameter at the end, and that the orifice be approximately 0.8 mm 6 0.05 mm (1⁄32 in.) in diameter. A test flame relighting device, such as a pilot flame, is sometimes used to automatically relight the test flame if it is extinguished during the test. This device should be designed such that the unburned gas will not spread out over the test cup during the relighting.

 

For Cleveland, Open Cup Apparatus (automated) fill the test cup with the sample so that the top of the meniscus of the test specimen is level with the filling mark and position the test cup on the center of the heating plate. The temperature of the test cup and the sample shall not exceed 56 °C (100 °F) below the expected flash point. Light the test flame, when necessary, and adjust it to a diameter of 3.2 mm to 4.8 mm (1⁄8 in. to 3⁄16 in.) or to the size of the comparison bead if one is mounted on the apparatus. Start the automated apparatus according to the manufacturer’s instructions. The apparatus will follow the same procedure details as described above.

 

Ambient barometric pressure is recorded at the time of the test. When the pressure differs from 101.3 kPa (760 mm Hg), correct the flash point or fire point, or both, as follows:

Corrected flash point 5 C10.25 ~101.3 2 K! ….1

Corrected flash point 5 F10.06 ~760 2 P! …….2

Corrected flash point 5 C10.033 ~760 2 P! …..3

 

This test method shall be used to measure and describe the properties of materials, products, or assemblies in response to heat and a test flame under controlled laboratory conditions. Results of this test method may be used as elements of a fire risk assessment that considers all the factors that are pertinent to an assessment of the fire hazard of a particular end use.