UL 2846-2021 pdf download

UL 2846-2021 pdf download.Fire Test of Plastic Water Distribution Plumbing Pipe for Visible Flame and Smoke Characteristics.
3.1.5 The ladder-type tray used to support the test specimens is shown in Figure 3.2 and Figure 3.3. The tray is to be fabricated from cold-rolled steel, 50,000 psi minimum (350 MPa) tensile strength. The solid- bar-stock side rails are to be as shown in Figure 3.3. The C-shaped channel rungs are to be as shown in Figure 3.3. Each rung is to be 11-1/4 inches (286 mm) long. The rungs are to be welded to the side rails 9 inches (229 mm) on centers along the tray length. The tray is capable of consisting of several sections having a total assembled length of 23.9 feet (7.28 m) and is to be supported with 16 supports equally spaced along the length of the tray. The supports (see Figure 3.3) are to be fabricated from bar steel. 3.1.6 One end of the test chamber, designated as the “fire end” in Figure 3.1, is to be provided with two gas burners delivering flames upward that engulf the test specimens. As shown in Figure 3.2, the burners are to be positioned transversely to each side of the centerline of the furnace so that the flame is evenly distributed over the width of the specimens. 3.1.7 The controls used to maintain a constant flow of gas to the burners are to consist of a pressure regulator; a gas meter calibrated to read in increments of not more than 0.1 cubic foot (2.88 mm 3 ); a gauge to indicate gas pressure in inches of water (Pa); a quick-acting gas-shutoff valve; a gas-metering valve; and an orifice plate in combination with a manometer to assist in maintaining uniform gas-flow conditions. An air intake fitted with a vertically-sliding shutter extending the entire width of the test chamber is to be provided at the fire end. The shutter is to be positioned to provide an air-inlet port as shown in Figure 3.1. 3.1.8 The other end of the test chamber, designated as the “vent end” in Figure 3.1, is to be fitted with a rectangular-to-round transition piece which, in turn, is to be fitted to a round flue pipe. The movement of air is to be by induced draft.
3.3 Temperature measurement 3.3.1 An 18 AWG thermocouple [nominal wire cross section of 1620 cmil (0.823 mm 2 )] with 0.375±0.125 inch (10 ±3 mm) of the junction exposed in the fire chamber air is to be inserted through the floor of the test chamber so that the tip is 1.0 ±0.031 inch (25 ±1 mm) below the top surface of the gasketing tape and 23 feet ±1/2 inch (7.09 m ±13mm) from the centerline of the burner ports, and at the center of the width of the chamber. 3.3.2 An 18 AWG thermocouple [nominal wire cross section of 1620 cmil (0.823 mm 2 )] embedded 1/8 inch (3.2 mm) below the floor surface of the test chamber is to be mounted in refractory or Portland cement (carefully dried to keep it from cracking) at distances of 13-1/2 and 23 feet (3.96 and 7.09 m) from the fire end of the burner ports. 4 Test Specimens 4.1 Two 24 foot (7.32 m) lengths of plastic pipe, less than or equal to 4 inches (10.2 cm) inside diameter, if uninsulated, less than or equal to 5 inches (12.7 cm) outside diameter, if an insulated pipe assembly, are to be installed in the bottom of the tray. The specimen is to be laid in the center of the tray with a minimum separation between the individual pipes of 0.5 inches (12.7 mm). There shall be no water or any other liquid in the pipe during the test. 4.2 The pipe specimen is to be placed on a mesh screen in the tray. The mesh screen is galvanized wire cloth with 0.047 inch (1.2 mm) wire diameter and having 3/4-inch (19-mm) openings. The two lengths of pipe are to be fastened to the screen with fasteners as described in 4.3. 4.3 Bare copper tie wires not larger than 18 AWG [nominal wire cross section of 1620 cmil (0.823 mm 2 )] are to be used to fasten the specimen to the mesh screen and rungs of the tray wherever a tie is required to keep a specimen in contact with the rung and to minimize movement during the test. A tie is not to be used in any manner that alters the ability of the specimen to transmit gases and/or vapor longitudinally through the core of the specimen. UL 2846-2021 pdf download.