UL 2846:2016 pdf free download – STANDARD FOR SAFETY Fire Test of Plastic Water Distribution Plumbing Pipe for Visible Flame and Smoke Characteristics.
3.3 Temperature measurement
3.3.1 An 18 AWG thermocouple [nominal wire cross section of 1620 cmil (0.823 mm2)] 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 mm2)] 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 mm2)] 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.
4.4 Properties applicable to identification of the specimens, including the type, thickness, and manufacturer of thermal insulation, if used, are to be determined and recorded.
5 Calibration of Test Equipment
5.1 One 1/4-inch (6.3-mm) thick mineral-fiber/cement board is to be placed on the ledge of the furnace chamber as shown in Figure 3.2. The removable top of the test chamber is to be placed in position.
5.2 With the board in position and with the removable top in place, the draft is to be established to produce a 0.15-inch water column reading (37 Pa) on the draft manometer with the fire-end shutter open 3 ±1/16 inches (76 ±2 mm) and with the manual damper in the wide-open position. Then, the fire-end shutter is to be closed and sealed. The manometer reading is to increase to at least a 3/8-inch water column (93 Pa), indicating that no excessive air leakage exists.
5.3 In addition, a supplemental leakage test is to be conducted periodically by activating a smoke bomb in the fire chamber while the fire shutter and exhaust duct beyond the differential manometer tube are sealed. The bomb is to be ignited and the chamber is to be pressurized to a 0.375 ±0.15-inch water column (93 ±37 Pa). All points of leakage observed in the form of escaping smoke particles are to be sealed.