UL testing for fire tests of window assemblies

ULTesting: UL testing for fire tests of window assemblies

UL testing for fire tests of window assemblies

3 Control of Fire Tests

3.1 Time-temperature curve

3.1.1 The fire exposure of window assemblies shall be controlled to conform to the applicable portion of the standard time-temperature curve shown in Figure 3.1. The points on the curve that determine its character are:

1000�F (538�C) at 5 minutes

1300�F (704�C) at 10 minutes

1462�F (795�C) at 20 minutes

1550�F (843�C) at 30 minutes

1638�F (892�C) at 45 minutes

1700�F (927�C) at 1 hour

1792�F (978�C) at 1-1/2 hours

1850�F (1010�C) at 2 hours

1925�F (1052�C) at 3 hours

For a closer definition of the time-temperature curve, see Appendix A.

3.2 Furnace temperatures

3.2.1 The temperatures of the test exposure are to be the average temperature obtained from the readings of not less than nine thermocouples symmetrically disposed and distributed to show the temperature near all parts of the test assembly. The thermocouples are to be protected by sealed porcelain tubes having 3/4 inch (19.1 mm) outside diameter and 1/8 inch (3.2 mm) wall thickness or, as an alternate in the case of base-metal thermocouples, protected by sealed 1/2-inch (12.5-mm) wrought-steel or wrought-iron pipe, in accordance with Welded and Seamless Wrought Steel Pipe, ANSI/ASME B36.10M, of standard weight. See Figure 3.2. The exposed length of the thermocouple protection tube in the furnace chamber is not to be less than 12 inches (305 mm). The junction of the thermocouples is to be 6 inches (152 mm) from the exposed face of the test assembly, or from the construction in which the assembly is installed during the entire test exposure.

3.2.1 revised April 12, 2005 issued April 12, 2005

3.2.2 The temperatures are to be read at intervals not exceeding 1 minute.

3.2.2 revised April 12, 2005 issued April 12, 2005

 3.2.3 The accuracy of the furnace control is to be such that the area under the time-temperature curve, obtained by averaging the results from the thermocouple readings, is within 10 percent of the corresponding area under the standard time-temperature curve for fire test of 1 hour or less duration, within 7.5 percent for those over 1 hour and not more than 2 hours, and within 5 percent for tests exceeding 2 hours in duration.

3.2.4 Deleted April 12, 2005

3.3 Furnace Pressure

3.3.1 Furnace pressures are to be read at intervals not exceeding 1 minute.

3.3.1 added April 12, 2005 issued April 12, 2005

 3.3.2 Control of the furnace pressure is to be established beginning no later than 5 minutes after the start of the test and is to be maintained throughout the remainder of the fire test.

3.3.2 added April 12, 2005 issued April 12, 2005

 3.3.3 The vertical pressure distribution within the furnace is to be measured by at least two pressure-sensing probes separated by a minimum vertical distance of 6 feet (1.8 m) inside the furnace for furnaces with a minimum vertical dimension of 10 feet (3.05 m). Minimum vertical separation between pressure probes is to be reduced proportionally for furnaces with an internal dimension less than 10 feet (3.05 m).

3.3.3 added April 12, 2005 issued April 12, 2005

3.3.4 The pressure-sensing probes are to be as shown in either Figure 3.3 or Figure 3.4.

3.3.4 added April 12, 2005 issued April 12, 2005

Note: 1 inch = 25.4 mm

3.3.5 The pressure-sensing probes are to be located within 6 inches (152 mm) of the vertical centerline of the furnace chamber.

3.3.5 added April 12, 2005 issued April 12, 2005

3.3.6 The pressure at each location is to be measured using a differential pressure instrument capable of reading in increments no greater than 0.01 inch water gauge (2.5 Pa) with an accuracy of �0.005 inch water gauge (�1.2 Pa) or better. The differential pressure measurement instrument is to be located so as to minimize stack effects caused by vertical runs of pressure tubing between the pressure-sensing probes and the differential pressure measurement instrument locations.

3.3.6 added April 12, 2005 issued April 12, 2005

3.3.7 Based on the vertical separation and pressure differences between the two pressure-sensing probes, a calculation of the zero pressure plane is to be made. The furnace pressure is to be positive above the zero pressure plane.

3.3.7 added April 12, 2005 issued April 12, 2005

3.3.8 For fire tests conducted under positive pressure conditions, the zero pressure plane is to be established such that at least two-thirds of the height of the window assembly is located above the zero pressure plane.

3.3.8 added April 12, 2005 issued April 12, 2005

3.3.9 For fire tests conducted under neutral pressure conditions, the zero pressure plane is to be established such that it is located within �1 inch (�6 mm) of the top of the window assembly.

3.3.9 added April 12, 2005 issued April 12, 2005

4 Test Assemblies

4.1 Construction and size

4.1.1 The design, construction, material, workmanship, and hardware of the test assembly is to be representative of the construction under evaluation. A record of materials and construction details adequate for identification is to be made.

4.1.1 revised April 12, 2005 issued April 12, 2005

 4.1.2 The area of the test assembly is not to be less than 100 square feet (9.29 m²) with neither dimension less than 9 feet (2.7 m).

4.1.3 If the conditions of use limit the construction to smaller dimensions, a proportionate reduction may be made in the dimensions of the test assembly for tests qualifying them for such restricted use.

  4.2 Mounting

4.2.1 The test assembly is to be installed in the wall or partition construction in the manner in which it is to be used. It is to be mounted so that the latches and fasteners other than hinges will be on the unexposed side, and the mounting is not to prevent the free and easy operation of all operable components such as ventilators and sash.

4.2.2 The wall or partition is to be constructed of masonry or other materials representative of the wall or partition construction. Window frame wall anchors, when used, are to be suitable for the wall or partition constructed.

5 Conduct of Tests

5.1 General

5.1.1 The wall or partition is to have sufficient strength at the time of the test to retain the assembly securely in position throughout the fire and hose stream test.

5.1A Heat flux

5.1A.1 The radiative heat flux transmitted through the test assembly is to be measured when requested by the test sponsor. The flux measurements are to be recorded at least once every minute.

5.1A.1 added April 12, 2005 issued April 12, 2005

5.1A.2 The radiative heat flux is to be measured by an instrument capable of measuring radiant heat flow having a range of 0 to 50 kW/m² with an accuracy of �5% of the maximum range. The response time of the instrument is to be such that the instrument is capable of recording 64% of the maximum range within 10 seconds. The view angle of the instrument is to be 180 �5�.

5.1A.2 added April 12, 2005 issued April 12, 2005

5.1A.3 The radiative heat flux is to be measured in a plane parallel, and at a distance of 39 �3/8 inches (1.0 �0.01 m) from the unexposed surface of the test assembly.

5.1A.3 added April 12, 2005 issued April 12, 2005

5.1B Unexposed surface temperatures

5.1B.1 The temperatures on the unexposed surface of the glazing materials are to be measured when requested by the test sponsor. The temperature measurements are to be recorded at least once every minute.

5.1B.1 added April 12, 2005 issued April 12, 2005

5.1B.2 When measured, the temperatures are to be measured with thermocouples with a wire diameter of not more than 0.03 inch (0.7 mm). Each thermocouple is to be brazed to the center of the face of a copper disk 1/2 inch (12 mm) in diameter and 0.01 inch (0.2 mm) thick, which is secured to the surface of the specimen at the required position. The thermocouples are to be placed under flexible, oven-dry, felted pads. The properties of these pads are to comply with the requirements specified in Appendix B, Requirements for Thermocouple Pads.

5.1B.2 added April 12, 2005 issued April 12, 2005

5.1B.3 When measured, the unexposed surface temperatures are to be taken at not less than two points, with a minimum of one thermocouple in each 16-square foot (1.5 m²) area of the glazing material. Thermocouples are not to be located more than 12 inches (305 mm) from the edge of the framing.

5.1B.3 added April 12, 2005 issued April 12, 2005

5.1B.4 The disk and the pad are to be fixed to the surface of the specimen by a sodium silicate (water glass) adhesive or an adhesive that is rated for use at temperatures equal to or greater than 700�F (370�C).

5.1B.4 added April 12, 2005 issued April 12, 2005

5.1B.5 The thermocouples and pads are to be removed after 30 minutes of fire exposure.

Exception: The thermocouples and pads are to remain on the assembly when unexposed surface temperature data beyond the first 30 minutes of fire exposure is being evaluated.

5.1B.5 added April 12, 2005 issued April 12, 2005

5.2 Fire endurance test

5.2.1 The pressure in the furnace chamber is to be maintained as described in 3.3.8 for window assemblies tested under positive pressure conditions, and as in 3.3.9 for window assemblies tested under neutral pressure conditions.

5.2.1 revised April 12, 2005 issued April 12, 2005

5.2.2 The test is to be continued for the predetermined test exposure unless the conditions of acceptance set forth in Section 6 are exceeded in a shorter period.

5.2.2 revised April 12, 2005 issued April 12, 2005

5.2.3 The distance between the junction of the thermocouples used to measure furnace temperature is to be adjusted during the test so that the distance remains at 6 �1 inches (152 �25 mm) during the test.

5.2.3 added April 12, 2005 issued April 12, 2005

5.3 Hose stream test

5.3.1 Immediately following the fire endurance test and within 1-1/2 minutes, the fire exposed side of the test assembly is to be subjected to the impact, erosion, and cooling effects of the hose stream.

5.3.2 The hose stream is to be delivered through a 2-1/2-inch (63.5-mm) hose discharging through a National Standard playpipe of corresponding size equipped with a 1-1/8 inch (28.6 mm) discharge tip of the standard-taper smooth-bore pattern without shoulder at the orifice.

5.3.3 The tip of the nozzle is to be located 20 feet (6.1 m) from, and on a line normal to, the center of the test assembly. If such a location is not possible, the nozzle may be on a line deviating not more than 30 degrees from the line normal to the center of the test assembly. When so located, the distance from the plane of the surface of the test assembly is to be less than 20 feet (6.1 m) by an amount equal to 1 foot (305 mm) for each 10 degrees of deviation from the normal.

5.3.4 The hose stream is to be directed around the periphery of the test assembly starting upward from a lower corner. When the circuit is approximately 1 foot (305 mm) from the starting point, the hose stream is to be applied in paths approximately 1 foot apart up and down the assembly across the entire width and then back and forth horizontally across the entire height. The traverse rate of the hose stream across the assembly is to be 3 to 6 feet per second (0.9 to 1.8 meters per second).

5.3.4 revised April 12, 2005 issued April 12, 2005

5.3.5 The water pressure at the base of the nozzle and duration of application in seconds per square foot (s/m²) of exposed area shall be as prescribed in Table 5.1.

Table 5.1

Water pressure at base of nozzle and duration of application