Vol 2 - Garney Construction

3. Support Spacing:a. 24 Inch Diameter and Larger: 20 feet, maximum.b. 20 Inch Diameter and Smaller: 15 feet, maximum.L. Marking:1. Identify each duct component with fabricator’s name, resin, minimumthickness, and date of manufacture.2. Use permanent marking. Seal decals and labels into laminate exteriorwith resin.3. For piece marking used for installation, use oil-based paint for easyremoval.M. Cure products to at least 90 percent of minimum Barcol hardness specified byresin manufacturer.N. Butterfly Dampers:1. Dampers:a. Single-blade type, complete with channel-type frame, close-fittingaxle, and bearings.b. Same inside diameter as connecting ductwork.c. Axles not less than 3/4 inch in diameter and shall be continuousthrough damper.d. When used for isolation service, shall be furnished with blade sealand shaft seal.e. When used for balancing only, shall be furnished with fullcircumference molded in blade stop.f. Isolation dampers shall have maximum leakage rate of 1 cubic feetper minute per square foot of damper area, at a differentialpressure of 12 inches WC.2. Design Requirements:a. Each damper shall be designed for the following conditions:1) Air Temperature Range: 45 degrees F to 104 degrees F.2) Differential Pressure: 12 inch WC.3. Materials:a. FRP materials for dampers shall be same resin as used inductwork.b. Requirements for flame spread and smoke development shall besame as required for ductwork.4. Construction:a. Frames: Fiberglass reinforced plastic with resin as describedherein.THERMOSET FIBERGLASS-REINFORCEDPW/WBG/382059PLASTIC DUCTS AND ACCESSORIES AUGUST 15, 201223 31 16.16 - 6 ©COPYRIGHT 2012 CH2M HILL