Open Cup Method

Flash Point (ASTMD92). The Cleveland open cup method is most commonly used although the Tag open cup (ASTM D3143) is apphcable to cutbacks. Flash point is an indication of fire hazard and the test is frequendy used to indicate whether a given product has been contaminated with materials of lower dash point. 

Flashpoint — the lowest temperature of a liquid at whieh it gives off enough vapor to form an ignitable mixture with air near the surfaee of the liquid within the vessel used. Two tests are used—Open Cup and Closed Cup. Generally, the Open Cup method results in flashpoints 5° to 10° higher than the Closed Cup method. Flashpoint < 140°F (Closed Cup) is the eriterion used by EPA to deeide whether a ehemieal is hazardous by ignitability. DOT defines materials with flashpoints of < 100°F as flammable materials, and between 100° and 200°F as eombustible. 

The flash pt for IPN using the Abel closed cup method is 53°F while the Cleveland open cup method gives a value of 72°F. Min spont ign temp range in air on a heated brass, Al stainless steel or mild steel plate is 245—60° The following data from Ref 6 present, in tabular form, the limits of flammability of IPN vapor/air mixts over a press and temp range ... 

Of the available test methods, the most common method of determining the flash point confines the vapor (in a closed cup) until the instant the flame is applied (ASTM D56, D93, D3828, D6450 IP 34, IP 94, IP 303). An alternative method that does not confine the vapor (open cup method ASTM D92, D1310 IP 36) gives slightly higher values of the flash point. 

These are liquids, mixtures of liquids, or liquids containing solids in solution or in suspension. The flash point of these materials is 140°F (60°C) or less by the closed-cup method or 150°F (65.5°C) or less by the open-cup method. 

A. FLASH AND FIRE POINTS BY CLEVELAND OPEN CUP METHOD (COC). The Cleveland Open Cup Apparatus is described as Method 4294 (Sept 1965) of Federal Test Method Standard No 141a... 

Hash and fire points by Cleveland open cup method 6 F80-F82... 

The flash point is a measured temperature at which vapors above the surface of a liquid are just sufficiendy concentrated to propagate a flame (10). In practice, materials of concern may be in closed or open containers or may have spilled. Generally, the chosen flash point method should be related to the problem as well as to the type of material ie, open-cup methods are more significant for open containers or spills, whereas closed-cup methods give more significant information for closed containers, eg, process vessels. A number of commercial flammable liquids contain a moderate amount of noncombustible components, eg, chlorinated hydrocarbons, in order to elevate the closed-cup flash point and thus gain a more favorable classification. When the same material is analyzed by an open-cup method, the flash point is not elevated, ie, after a spill, the noncombustible material would soon be lost and the residue may be highly flammable. 

The following table lists some of the more important properties of hazardous room temperature solids commonly used in the analytical laboratory.1 The flash points were determined with the open-cup method. 

CC Closed Cup method for the measurement of the flash point. With this method, Sample vapors are not allowed to escape as they can with the open cup method. Because of this, flash points measured with the CC method are usually a few degrees lower than those measured with the OC. The choice between CC and OC is dependent on the (usually ASTM) standard method chosen for the test. 

Standard methods for the determination of the critical temperatures are published by the AOCS (AOCS Official Methods Cc 9a 48 (smoke, flash and fire points by an open cup method), and Cc 9b-55 and Cc 9c 95 (flash point by open cup methods), Firestone, 1998) and by the British Standards Institution (BS 684 Section 1.8 1976 (smoke point), BSI, 1976b and BS 684-1.17 1998/ISO 15267 1998 (flashpoint by a closed cup method), BSI, 1998b). 

Smoke, Flash, and Fire Point—Cleveland Open Cup Method (Cc 9a-48) determines the temperatures at which fats and oils smoke, flash, or burn. Smoke point determinations sometimes are used to follow degradation of frying oils with use. 

Usually, flashpoint is measured in air. Open cup methods may overestimate the flashpoint for liquids containing multiple components because of the loss of more volatile components during testing. Nevertheless, open cup testers can provide flashpoint for situations of open vessels and spills. In contrasts, closed cup techniques prevent the loss of volatile components by keeping the sample enclosed until the ignition source is introduced, and therefore, closed cup data are more conservative than and generally preferred to open cup data. 

The Pensky-Marten apparatus using a closed or open system (ASTM D-93, IP 34, IP 35) is the standard instrument for flash points above 50°C (122°F), and the Abel apparatus (IP 170) is used for more volatile oils, with flash points below 50°C (122°F). The Cleveland open-cup method (ASTM D- 92, IP 36) is also used for the determination of the fire point (the temperature at which the sample will ignite and bum for at least 5 s). 

The fire point is the temperature to which the product must be heated under the prescribed test conditions to cause the vapor-air mixture to bum continuously on ignition. The Cleveland open cup method (ASTM D-92, IP 36) can be used to determine both flash and fire points of lubricating oils, and the Pensky-Martens closed (ASTM D-93, IP 34) and open (IP 35) flash points are also widely used. 

Flash point ASTM D-92 Cleveland open cup method is commonly... 

Note Flash points are determined by the ASTM Pensky-Martens Closed Cup Method and fire points by the ASTM Cleveland Open Cup Method. 

SFS-EN 22592. Petroleum products. Determination of flash and fire points. Cleveland open cup method (ISO 2592). 

FLASH AND FIRE POINT - CLEVELAND OPEN CUP METHOD... 

The flash point of the paving grade bitumens as determined by the Cleveland open cup method may vary from >165°C to >245°C for cut-backs of flashed bituminous binders, the flash point may be >160°C. 

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