UL 711:2018 pdf free download

UL 711:2018 pdf free download UL 711, Rating and Fire Testing of Fire Extinguishers
7.1.3 The minimum effective discharge time shall be at least 13 seconds for an extinguisher intended for a 2-A or higher rating class.
7.1.4 The minimum effective discharge time is to be determined by an operation test of an extinguisher charged with its rated capacity at 21 ±3°C (70 ±5°F) while being held in its intended operating position.
7.1.5 The extinguishment of test fires for Class A water extinguishers is primarily a function of the amount of water and the duration and range of its discharge. Extinguishers up to and including 125 L (33 gal) water capacity and otherwise conforming to the appropriate requirements for discharge capacity, duration, and range are eligible for rating without fire testing. In such cases the class and rating is to be applied in accordance with Table 1.
7.1.6 Other fire extinguishing agents or water-type extinguishers utilizing improved application methods which develop greater Class A extinguishing potential provided for in Table 1 shall be subjected to fire tests to determine the Class A rating. 7.1.7 Class A extinguishers to be rated on the basis of tests for Rating-Class 1-A through 6-A shall be subjected to the appropriate wood crib and wood panel test fires. Class A extinguishers for Rating-Class 10-A or higher shall be rated on the basis of appropriate wood crib test fires only.
7.2 Wood crib fire test
7.2.1 A wood crib is to consist of layers of 38 by 38 mm trade size [2 by 2 (1-1/2 by 1-1/2 in)] or size 38 by 89 mm trade size [2 by 4 (1-1/2 by 3-1 /2 in)] kiln-dried spruce or fir lumber having a moisture content of 9 to 15 percent as determined by the Standard Test Methods for Direct Moisture Content Measurement of Wood and Wood-Base Materials, ASTM D4442, in which samples are dried to constant weight in an oven at a temperature of 103 ±2°C (217 ±3°F). A hand-held meter employed in accordance with the Standard Test Methods for Use and Calibration of Hand-Held Moisture Meters, ASTM D4444, is also used to provide a means of sampling moisture content prior to testing. The general configuration and support of a typical crib is illustrated by Figure 1. The alternate layers are to consist of specified sizes and lengths of lumber placed at right angles to one another. The individual wood members in each layer are to be evenly spaced in forming a square determined by the specified length of the wood members. The length, size, and number of individual wood members and their arrangement in the crib are to be as specified in Table 2.
7.2.2 The crib is to be on an angle iron frame, mounted on a weighing platform as shown in Figure 1, at a height of 400 mm (1 6 in) above the floor or grade level. The wood members forming the outside edges of the crib are to be stapled or nailed together to provide strength to resist forces exerted by the extinguisher discharge.
7.2.3 The net mass of the crib is to be determined prior to commencement of the test. A value equivalent to 55 percent of this mass is to be calculated for wood crib sizes 1-A through 10-A. A value equivalent to 65 percent of this mass is to be calculated for wood crib sizes 20-A and larger.
7.2.4 Ignition of the crib is to be accomplished by the burning of commercial grade heptane, see 8.2.4, in a pan placed symmetrically under the vertical axis of the crib. The steel pans for all sizes are to be square. The dimensions of the pan and the amount of fuel to be burned are to be as specified in Table 3.