Bitumen Flash and Fire Point Test Definition and Method
Vapor is produced close to the surface of flammable or combustible material during heating. The flash point test determines the lowest temperature at which the vapor ignites and produces an immediate flame when present with an ignition source.
The temperature higher than the flash point is measured using the fire point test. The flame burned for over five seconds at the fire spot.
The National Fire Protection Association (NFPA) states that combustible liquids have a flash point that is equal to or higher than 100 °F (37.2 °C), whereas flammable liquids have a flash point that is lower than 100 °F (37.2 °C).​
The "Cleveland open cup tester" and the "Pensky-martens" are two well-known instruments used to gauge the Bitumen's Flash and Fire Point.
All bituminous compounds with a Flash Point between 79 °C and 400 °C can be used with these equipment.
Pouring the sample into the test cup initiates the test. The temperature of the sample rises. A test flame is used to ignite the sample vapor at the flash point temperature. Continue heating the sample until a flame appears above it in order to identify the fire point. The flam must burn for a minimum of five seconds.
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Flashpoint
The Flash and Fire Point Test: Why Is It Important?
Bituminous substances can catch fire. Their use, handling, and storage are therefore always dangerous. To reduce the risk of fire and improve safety, it is crucial to understand flash and fire point.
Standard Procedures for Bitumen Flash and Fire Point Testing
The following are a number of accepted techniques for calculating bitumen flash and fire point:
EN ISO 2592 | ASTM D 92 | ASTM D 93 | ASTMD 3143 | ASTM D8254 | AASHTO 48 | AASHTO 79 | IS 1448 | IS 1209 | IP 113 | IP 170
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The Flash and Fire Point Tests are carried out in accordance with ASTM D 92 as follows:
Cleveland Open Cup Tester's Flash and Fire Point: Component:
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A Heating Plate
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A Brass Test Cup
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Bead: It is affixed to the top of the apparatus. As a result, the size of the flame can be compared
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Temperature Controller: for managing the heater
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Test Flame Applicator: A tool for distributing test flame. It swings from right to left and left to right and has a hole. It is situated 2 mm above the test cup's rim's plane.
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Thermometer
The table above lists the flash points for several grades of bitumen based on Indian Bureau standards (IS 1448)
Cleveland Open Cup Tester
Methods
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All varieties of bitumen are acceptable for this test. Bitumen samples that are solid should be heated until they are fully liquid. High temperatures must not be used to heat bitumen. The ideal heating temperature is roughly below the anticipated flash point.
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Until the filling line is level, fill the dry, clean test cup. Bitumen that has reached levels over the file line needs to be removed using a pipette or syringe.
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Make sure the bitumen sample's surface is bubble-free; otherwise, the test will fail.
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Insert the thermometer into the test cup vertically. Fire the test flame after that.
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Utilizing the regulator, apply the heat. The sample should warm up at a rate of 5–17 °C each minute.
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A heating rate of 5 to 6°C per minute is advised from the start of the test to the finish if the material has a low flash point or is extremely viscous.
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Reduce the heater's heat until the test temperature is about 56 °C below the anticipated flash point. The sample's temperature should be rising at a rate of between 5 and 6 °C per minute in order to continue the test.
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Apply the test flame to move at 28 °C below the predicted flash point. The test flame must pass over the sample each time its temperature increases by 2 °C.
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Note the temperature at which a fire suddenly emerges above the surface of the bitumen. The flash point can then be calculated using equation 1.
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Continue heating the sample once you reach the flash point to find the fire point. 5 to 6 °C should be added to the sample temperature per minute.
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Keep track of the temperature for at least five seconds at which the flame first appears over the bitumen surface. Use equation 1 to determine the firing point after that.
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Flash or Fire Point is equal to C+ 0.033*(p-760) (1).
where :
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C = the test's result's temperature in degrees Celsius.
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P = Barometer reading of the ambient pressure in MM, Hg
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Note: The maximum difference between the highest and lowest values in repeated measurements for each sample by the same instrument must be less than 8 °C.
Pensky-Martens
What distinguishes a flash point from a fire point?
The distinction between a petroleum product's flash point and fire point is that a petroleum product's flash point is the lowest temperature at which it creates flammable vapor that can ignite when exposed to flame. As soon as the source of flame is eliminated, the flash point will end. However, the fire point is the temperature at which a flame starts to burn continuously when it passes over it. Temperature differences between the fire point and flash point exist.
Does bitumen catch fire?
Yes. Bitumen is combustible and can catch fire if it gets too hotใ