flammability test data in risk assessment

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70 THE ANNALS OF UNIVERSITY “DUNĂREA DE JOS“ OF GALAŢI FASCICLE VIII, 2008 (XIV), ISSN 1221-4590 TRIBOLOGY small scale the worst scenario that could happen in real applications, when using hydraulic fluids [2-5, 16-19]. A particularity of many of these tests is that the test result is delivered as “pass” or “not pass”. The fluids that passed the tests are included in recommendations or approvals, but these ones are specific to regional reglementations (in SUA: Approval Guide or List of Qualified Fluids, in European Union: [6, 7, 14, 16] or in national normatives: [3, 13, 15]). Organizations such as Occupational Safety and Health Association (OSHA), National Fire Protection Association (NFPA) and some specialists classify flammable liquids according to their flashpoint [10, 33, 34, 39, 41]. A flashpoint within the operating temperature range of the system obviously is undesirable as any leak would create an immediate fire hazard [20, 43]. The globalization of hydraulic fluid market involved studies on existing and proposed fireresistance and flammability tests in order that manufacturers and users of such fluids have common level of appreciating and comparing these products, their applications and possible effects [11, 23]. Selling into multiple markets is very difficult if each country or economic community has different requirements and standards on using hydraulic fluids. Many countries and firms subscribe to international standards, but there are important economies as USA, Japan ones that rely on their own standards, some of them similar to international ones, other ones being different. Users require that the products they buy have to be certified according to standards applied in their country. These have substantial financial implications concerning expenses on laboratories and test procedures, for both manufacturer and users [10, 40, 44]. The hydraulic fluid manufacturers have few possibilities for complying this challenge: making different products for different markets, making a single product that passes multiple tests (taking into account the potential of a cost disadvantage), selecting only some of the potential markets (international or domestic) accepting the risk of not being a “global” producer. The laboratories dealing with flammability and fire-resistance properties have the advantage that more tests implies more work, visibility and of course, money but it also requires disadvantages as: larger investment in equipment, a greater understandding of similarities and differences among related tests (including well-trained specialists), agreements for cross-border acceptance of the results [19, 20, 27]. The development of fire-resistant hydraulic fluids required the identification of test methods that could reproducibly differentiate the fire-resistance of the fluids in a manner that would relate to real industrial conditions [1, 25, 40]. Zinc elaborated a classification of types of fire tests [44] according to four elements (fig. 1): - the fire resistant property that is being measured as there are several different facets of fire resistance and a test can measure one or more of them, - the ignition source used in the test (almost all fire resistance tests ignite or attempt to ignite the fluid during the test), - the state of the fluid during the test, - whether the test simulates an accident condition or measures an intrinsic property of the fluid. Some tests are based on a simulated accident (either explicitly or implicitly) while others measuring an intrinsic property of the fluid are not based on the conditions of any particular accident mode. 3. TESTS FOR DETERMINING THE FLAMMABILITY CHARACTERISTICS OF FLUIDS IN CONTACT WITH HOT SURFACES Specialists give information on testers and methodologies that are related to flammability characteristics of fluids on hot surfaces but the methodologies and the procedures have a high degree of differentiation [24, 26, 29, 35, 38, 41]. The standard SR EN ISO 20823:2004 “Ţiţei şi produse înrudite. Determinarea caracteristicilor de inflamabilitate a fluidelor în contact cu suprafeţe calde. Încercarea de inflamabilitate pe metal cald” is the national adoption by the endorsement method of the standard EN ISO 20823:2003 Petroleum and related products - Determination of the flammability characteristics of fluids in contact with hot surfaces - Manifold ignition test (ISO 20823:2003). This standard gives a testing method for determining the relative flammability of the fluids when the fluid Fig. 1. Classification of fire tests.
THE ANNALS OF UNIVERSITY “DUNĂREA DE JOS“ OF GALAŢI FASCICLE VIII, 2008 (XIV), ISSN 1221-4590 TRIBOLOGY 71 Table 1. Fire tests for hydraulic fluids. Test Fluid state and ignition source / standards Measurements flash point Cleveland Open Cup Tester Temperature value for flash point [26, 36] ISO 2592:2001, ASTM D92-05a, BS 4689:1980, IP 36 fire point Cleveland Open Cup Tester Temperature value for fire point [10, 26] ISO 2592:2001, ASTM D92-05a open flame ignition of a fluid spray [28, 31, 42] spark ignition of a fluid spray [42] hot surface ignition of a fluid spray [24, 29, 42] open flame ignition of bulk fluid [40] flammability on hot surfaces (plate or manifold) [19, 39] autoignition of fluid ignition of fluid soaked rags [2, 11] ignition of fluid on an absorbent medium [16] spray from 6.89MPa hollow cone nozzle – ISO 15029-1, 7 th LR 3.1.2, FM 6930:2002, RP55H * , ASTM D5306- 92(2002)e1 open flames may range from that equivalent to a match to a blowtorch Sparks energy in the range of 2mJ…2J several types of sprays including that from ISO 15029-2, 7 th LR 3.1.3, RP55H * flat hot plates with fixed temperatures up to 600°C, the hot surface is moving through the fluid spray, varying inclination and surface temperature. a standard pool of fluid, a fluid stream on an inclined plate, exposed to an open flame; a range of open flame ignition sources the fluid drops are fallen on a manifold heated up to 700°C, i.e.: ISO 20823:2003 Federal Test Method 791, Method 6053.1. the determination of hot- and cool-flame autoignition temperatures of a liquid chemical in air at atmospheric pressure in a uniformly heated vessel. i.e.: DIN 51794, ASTM E659-78(2005) fluid-soaked mineral wool heated in an oven for an extended period of time at a fixed temperature. The test may provide pertinent information for safe transportation and storage. ISO 14935:1998, 7 th LR 3.1.3, RP66H * . the heat release rate of the ignition source occurrence and position of any ignition linear flame propagation rate the occurrence, energy and position of any ignition within the spray temperature of the hot plate measured usually by infrared unit ignition occurrence observations of any ignition, time to ignition and shape and position of the flame manifold temperature may be fixed up to 700°C any noticed ignition, persistence of burn, flash on, above or under the tube autoignition temperature ** bulk temperature, exposure time and occurrence of any exothermal process are monitored assessment of the persistence of a flame applied to the edge of a wick of nonflammable material immersed in fireresistant fluid. 7 th LR - 7 th Luxembourg Report * All CETOP Technical Recommendations are no longer available for purchase from June 2002 and are officially withdrawn but similar text might have been included in other official documents. ** This standard should be used to measure the properties of materials, products, or assemblies in response to heat and flame under controlled laboratory conditions and should not be used to describe or appraise the fire hazard or fire risk of these under actual fire conditions. However, results of this test may be used as elements of a fire risk assessment which takes into account all of the factors which are pertinent to an assessment of the fire hazard of a particular use. Table 2. Comparing two testing methods for testing fluid flammability on hot surfaces. Manifold Ignition Test (Federal Test Method 791, Method 6053.1) [40], EN ISO 20823:2003 Petroleum and related products - Determination of the flammability characteristics of fluids in contact with hot surfaces - Manifold ignition test Test parameters simulated manifold is heated at 700°C, temperature measured in three points, fluid volume rate: 10 ml in 40...60 sec; fluid temperature 20...25°C, dispenser tip at 300mm above the probably impact point on the manifold, sheet metal box 300 x 300 x 450 (mm) Test evaluation I(T), when the fluid flashes or burns on the tube but does not continue to burn when collected in the tray below, I(D), when the fluid flashes or burns on the tube and continues to do so when collected in the tray below, N when the fluid does not flash or burn at any time. N when the fluid does not flash or bur nat any time. simulated manifold is heated at 704°C (1300°F), temperature measured at one point in the central zone of the manifold, fluid volume rate: 10 ml in 40...60s sheet metal box: 300 x 300 x 460 (mm) a. flashes and burns on the manifold but not after dripping from the manifold, b. does not flash or burn on the manifold but does after dripping from the manifold, c. the fluid does not flash or burn on manifold or after dripping from the manifold. contacts a hot metallic surface having at fixed temperature. The method also allows establishing the ignition temperature of the studied fluid by varying the manifold temperature. The standard ISO 20823 was the subject of a debate in the ISO/TC 28 [44]. The method appears simply but it has not to be vague, so many comments were done on expressing the principle, the method
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flammability test data in risk assessment

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