What is SMACNA?
The first foot of fill should be shovelled on top of the duct. In all cases, the upper attachments to the decking should be in place before the application of fireproofing materials.NOTICE: See Addendum No. Steel rod ties were not sized in Table 1-16M for lengths over 1000 mm because other options appear more practical and economical.You may interpolate for lengths between those listed.Duct dimensions shown on the contract drawings are for airflow area. The standard is not intended to limit the selection or the development of accessories for use with flexible duct.Designers should consult these references, illustrate the complete design on contract drawings, and make limited reference to the duct construction detail in this manual, if necessary.ASTM Standard C 1071, Standard Specifications for Thermal and Acoustical Insulation (Mineral Fiber, Duct Lining Material)Duct pressure classes are identified on the contract drawings.Surfaces to receive sealant should be clean, meaning free from oil, dust, dirt, rust, moisture, ice crystals, and other substances that inhibit or prevent bonding. 3″ w.g. Flanges larger than 5/8″ (16 mm) must be spot welded, bolted, riveted, or screwed as required to prevent separation and/or weld breakage. Powder-actuated fasteners may also be used on steel. The readings are not indicative of noise reduction because the frequency characteristic of the noise also changes. Manufactured inserts are available individually or in long lengths; the latter are generally used where many hangers will be installed in a small area, or where individual inserts cannot be precisely spotted at the time of placing the concrete.The criteria used by SMACNA in its test program and in development of new duct tables is as follows.Liners shall also be installed with mechanical fastening devices that:Flexible duct shall be supported at the manufacturer’s recommended intervals but at least every 5′ (1.5m). (1000 Pa) maximum length is 30″ (750 mm). Use a lock-forming grade of sheet material.RADIATION PROTECTION AT WALL OPENINGS21. Round aluminum duct construction is given in Table 3-3.Drainage facilities must be provided in the coil and eliminator sections of the casing to handle condensation on the cooling coil.ADC Standard FD-72R1 (Thermal, Friction Loss, Acoustical and Leakage Performance)To convert the steel tables to aluminum:Flexible ducts may come to the installer in compressed form in a variety of lengths. Concerns for energy conservation, humidity control, space temperature control, room air movement, ventilation, maintenance, etc., necessitate regulating leakage by prescriptive measures in construction standards. Ducts should not be compressed.systems must control connector length and notch depth on rectangular duct ends to facilitate sealing. Related Documents. Tapered sides and roofs should be avoided primarily because of the difficulty in developing adequate strength and air tightness at the joints. 5/8″ (16 mm) minimum tabs are required to close corners.If companion flange joints are used as reinforcements, those for 25" to 36" diameter shall be 1-1/2" × 1-1/2" × 3/16"; for 37" to 48" diameter 2" × 2" × 3/16"; for 40" to 60" diameter 2-1/2" × 2-1/2" × 3/16"; for 61" to 72" diameter 3" × 3" × 1/4".Figure E–Collar (Spin-in Straight)The static pressure and differential orifice pressure were measured by electronic pressure transducers, which in turn were calibrated and monitored by liquid manometers. Trapeze hangar tables were expanded to cover the 120″ (3 m) width range, with hanger rods 3″ (76 mm) from duct sides in the 97″ to 120″ range.Consult duct design texts and manufacturer’s data for loss coefficients.Installing two layers of material to meet a minimum liner thickness is not recommended. However, as the ductThe traditional use of aluminum sheet two gages (Brown and Sharp schedule) heavier than standard galvanized sheet gage DOES NOT MEET THE REQUIREMENTS FOR EQUIVALENT STRENGTH AND RIGIDITY. Codes normally require that ducts be reasonably airtight. Unfortunately, cross breaking results in concave areas between the break lines. 2-17 FLEXIBLE CONNECTIONS AT FANFIG. In some localities it is known as a slide lock seam.25. If field leak tests are required, appropriate test pressures and clear scope of testing must be specified.The designer must carefully evaluate pressure change in ducts and provide pressure relief measures where necessary. SYMBOL MEANING, SYMBOL. The contractor is obligated to select and use these construction details or their equivalent to satisfy the pressure level designated by the designer.In order to promote public education and public safety, equal justice for all,a better informed citizenry, the rule of law, world trade and world peace,this legal document is hereby made available on a noncommercial basis, as itis the right of all humans to know and speak the laws that govern them.Mechanically secured fasteners form a positive attachment to the sheet metal. 1-16 CORNER CLOSURES - STANDING SEAMSIf the faces of flanges are flush, thick-consistency sealant may be used in lieu of gasket.