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,715/25,/'31 07: 54 ", I 512 447 2248 ACDUST. CO~:EPTS, INC. PAI3E 07 Fabrication Procedures For: Alternate Duct Protection Methods Duct Protection System A f ~ r: I~ -I€I,l"1rnl!'t......,~ -I: ~,'e In. m~ f' -, -l .1 .._. ~1~___~ @) <z> <D I--'T ',r. mln Cross-Section through Lol'IQltudlnal CenterUne ot Duct L-: C,QW-S8I;1Ion tl'l'O\JGh T!'ave"e Centerline of Duct Outlet, Steel Air Duct Construction and support provisions are to be specified by the individual fire resistance design. The duct outlet 1$ to be equipped with a louvered steel air diffu!ier secured with steel fasteners. 2. GIISS Fiber Duct lining Glass fiber duct linings are to be a minimum of 1-in. thick. 3.0 to 5.0 pfe density, unfaced or faced with paper. foil, plastic film or asphalt emulsion Linings are affixed to the inside of ducts with adhesives and/or steel fasteners. 80th lining and adhesive is to have a flame spread ratir"lg of 25 or less. a smoke developed rating of 50 or less. and comply with all other specs outlined In NFPA Standard No w'A. The glas$ fiber lining IYIl,lst cover the full inside ,:>erimeter of the duct and extend at least 12-in, beyond the edges'of tha duct outlet. On the bottom of the duct, the lining should be cut flush with the edges of the duct 3. Acoustical Lay-In Panel . ,. ...'\.~F Any nominal iJi in. acoustical lay-in panel classified Underwriters laboratories, I ne. for use in fire resistant designs is acceptable. The panel should be positioned on top of the duct to extend at least 6-in. beyond the sides along the width of the duct. It should extend at least la-in, beyond the sides of the duct outlet along the length of the dual, (More than one panel may be butted together to form a panel of the required dimensions.) Panels are to have a flame spread rating of 25 or less. a smoke developed rating of 50 or tess, and comply with all other specifications outlined by NFPA Standard No. 90. 4. Asbestos Paper .. . Asbestos paper should be affixed to the duct outlet' w"ere specified by individual fire resistant designs. Duct Protection System B ,If> r rp -----[~'/." 1 -~ \.- I L l--_._~--1 Crose-Secllon Ihrough Longitu.i:ltnll Centerline of Duct Cr08ll-Sactlon through 1'n\Y81'$8 Centerline 01 D~. Outlet 1. Steel Air Duct Construction and support provisions are as specified in the individual designs. A louvered steel diffuser fastened securely with steel fasteners is to be provided 2. Mineral Wood Batts 1Y.1ln. thick mineral wool batts are to be uSCl1. The top piece should extend at least 3 in, beyond the sides of the duct and 6 in, beyond the edges of thE' duct outlet. Side pieces extend from the lower face of the top piece to the upper face of the ceiling membrane along the entire length of the top piece Side pieces are tied to the top piece with 18 gauge w!re, 1B~in, O.C, Material shall have a flame $pread I rating of 25 or le$$. asmoka devtflloped ratIng of 50 .. or less, and shalt comply with all other specifications outlin~d,.i~NFPA Standard No, 90A.,,:. , 3. A.sbestos Paper .. . ., Asbestbs paper should be affixed to the duct outlet where specified by individual fire resistant designs NOTE: The systems shown havR been 9vahliltRd to, thei, effectiveness in retardmg the transfer of heat into the ceiling space, They may be u.<;ed 8S altefn8te systems when specified in fire resistant designs, Thad/menslon shown between the bottom of the duct and the top of the ceiling membra"e is a minImum. Where hinged sheet steel dampers are specified they should be equipped with spring catches and corrosion~resistant Mnges. Dampers designed to close by gravity must be installed in the direction of the air flow.