Factory mutual apparatus

Although the Factory Mutual Apparatus [101] has never been proposed as a standard test method, it is briefly mentioned here since it has been used for basic research work by several organizations and contains a number of novel features. A 100 mm. square specimen is mounted in a vertical chimney and heated (up to 65 kW m") by banks of quartz lamps mounted outside the chimney. Preheated air or oxygen nitrogen mixtures are pa.ssed up the column at a constant rate. The apparatus has been mainly used to determine the fundamental fire properties of materials, although products such as cables have also been tested. 

The Ohio State University (OSU) calorimeter (12) differs from the Cone calorimeter ia that it is a tme adiabatic instmment which measures heat released dufing burning of polymers by measurement of the temperature of the exhaust gases. This test has been adopted by the Federal Aeronautics Administration (FAA) to test total and peak heat release of materials used ia the iateriors of commercial aircraft. The other principal heat release test ia use is the Factory Mutual flammabiHty apparatus (13,14). Unlike the Cone or OSU calorimeters this test allows the measurement of flame spread as weU as heat release and smoke. A unique feature is that it uses oxygen concentrations higher than ambient to simulate back radiation from the flames of a large-scale fire. 

Factory Mutual Corner Test. This is a large-scale comer test used to test building products (18—20). The test rig consists of three sides of a cube. The two walls are 15.24 and 11.58 m by 7.62 m tall. The ceiling is 9.14 x 15.24 m. The product to be tested is mounted on the walls and ceilings ia a manner consistent with the iatended use. The fire source is a 340 kg stack of wood pallets located ia the corner. In order to pass the test, no flame can propagate to any extremity of the walls or ceiling. The Factory Mutual flammabiHty apparatus is proposed to replace this test for certain appHcations (21). 

The generation of material vapors can be quantified in terms of 1) relationship between weight loss and sample temperature. AMTL used thermogravimetric techniques for such quantification (J ), and 2) the relationship between the generation rate of material vapors and the heat flux. Factory Mutual Research Corporation (FMRC) has developed a technique using FMRC s Small-Scale Flammability Apparatus (2-10), which was used for the quantification. 

Figure 1. Factory Mutual Small-Scale (50 kW-Scale) Flammability Apparatus...

Purged and Pressurized Enclosures for Electrical Equipment, NFPA 496, National Fire Protection Association, Quincy, MA, 1982 Approval Standard Intrinsically Safe Apparatus and Associated Apparatus for Use in Class I, II and III, Division 1, Hazardous Locations, Class No. 3610, Factory Mutual Research, Norwood, MA, Oct. 1979... 

Any transducer can be used with solvents rated flammable. The manufacturer must provide the capability to (1) continually purge the transducer with inert gas, usually nitrogen, (2) completely seal the circumference of the transducer enclosure, with the exception of at least two well-sealed connections for input and output of purge gas, (3) design a power supply and connections to the transducer which are rated for the appropriate flammability classification, and (4) have an independent organization (such as Factory Mutual) certify the entire apparatus as acceptable for that flammability classification. While the latter approval is not mandatory, no user should accept a transducer unit without it. 

The Fire Propagation Apparatus. The fire propagation apparatus was developed by FM Global Research (previously Factory Mutual Research Corp.). The test is described in ASTM E2058, Standard Test Methods for Measurement of Synthetic Polymer Material Flammability Using a Fire Propagation Apparatus... 

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