UL 2846-2016 pdf download

UL 2846-2016 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 Figures 3.2 and 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 ot the tray. The supports (see Figure 33) are to be fabricated from bar steel.
3.1.6 One end of the test chamber, designated as the lire 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 eventy 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 mom than 0.1 cubic foot (2.88 mm3); 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 maintainng unilomi gas-flow condihons. 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 ond in Figure 3.1, is to be fitted with a rectangular-to-round transition piece which, in turn, is to be lifted to a round flue pipe. The movement of air is to be by induced draft The draft-inducing system is to have a total draft capacity of at least 0 15 inch of water (37 Pa) with the specimens in place, with the shutter at the fire end open to its normal position, and with the damper (see Sechon C-C in F.gure 3.1) In the wide-open position. A draft-gauge manometer to indicate static pressure is to be inserted through the top at the mid-width of the tunnel, just downstream of the air-itake shutter (see Figure 31).
3,1.9 The damper is to be installed in the vent pipe downstream of the smoke-indicating attachment specified in 3.21.
3.1.10 An automatic draft- regulator controller is to be mounted in the vent pipe downstream of the manual damper. Other manual-, automatic-, or special draft-regulation devices are to be incorporated to maintain air-flow control throughout each test run.
3.1.11 The room in which the test chamber Is located is to have provision lot a free inflow of air to maintain the room at atmospheric pressure throughout each test run.
3.2 Smoke measurement
3.2.1 A liit sourcec is to be mounted on a horizontal section of the vent pipe at a point at which it is:
a) Preceded by a straiit run of round pipe at least 12 diameters or 16 feel (488 m) from the
vent end of the rectangular-to-round transition section and
b) Not affected by ftame from the test chamber.
The light beam Is to be directed upward along the vertical axis of the vent pipe. The vent pipe is to be insulated with hgh-temperature, mineral-composition material from the vent end of the chamber to the photometer location. A photoelectric celid having an overall light-to-cell path length of 36 ±2 inches (914 51 mm), 16 inches (406 mm) of which are taken up by the smoke in the vent-pipe interior as shown in Section C-C of Figure 3.1. The cell is to be connected to recording devices for indicating changes in the attenuation of incident light by passing smoke, particulate matter, and other effluents.
C A General Electric Model 44.05, 12-volt, sealed-beam, clear auto spot lamp or equivalent is capable of
being used for this purpose.
d A Weston Instruments No. 856B8 photronic cell with an overall light-to-cell path length of 36 ± 2 inches (914 ± 51 mm), or its equivalent is capable of being used for this purpose.
3.2.2 The output of the photoelectric cell is to be connected to a recording device that processes the signal into a continuous record of smoke obscuration according to the following formula.