- Upon receipt of approved construction drawing, the drawing shall be tagged and a statistical printout of the parts shall be made and forwarded to site engineer for approval.
- Upon receipt of approval of tagged list, the fabrication shall be stated.
- The Ducts of HVAC system shall be fabricated out of Hot Dipped Galvanized Steel Coil as approved by Consultants and/or DW 142 / ASHRAE / SMACNA.
- Straight ducts shall be manufactured on Computer Controlled fully Automatic Coil Line Machine.
- Grooved Corner Seam shall be used on the longitudinal joint of straight ducts. Automatic RAS sem closing machine shall be used for the purpose.
- Z-profile pleating will be provided for sheet stiffening at 150mm pitch.
- Fittings shall be fabricated on Computer Controlled Plasma Cutting System and assembling shall be done by using Pittsburgh Lock Seam.
- Seam closing shall be done by pneumatically operated guns, for a smooth finish.
- On ducting with S and C joints, C seam on the straight and duct fittings shall be achieved by pneumatically Operated Cleat-bender to 180 deg. Bend, to receive the Drive Slip.
- Minimum sheet thickness shall be filled as per Duct Construction table approved by Consultant.
- Ducts up to maximum certain size on larger dimension, slip joint shall be used.
- For the ducts above a certain size as per specification proprietary slide on flanges shall be fixed on the ducts in the factory, if required & ordered by client/contractor. Size of the flanges shall be selected as per Duct Construction Table approved by Consultants. Flanges shall be fitted automatically by Automatic Press-joining Clinching Technique to achieve a quality joint.
- Sealant shall be applied circumferentially to the transverse joints of ducts fitted with slide-on flanges, if required by the specification and ordered by client/contractor.
- Machine connections, Suit at site Piece, Droppers, shall be measured by installation contractor and sent to the factory for fabrication.
- Ducts shall be delivered to site in the side-bodies trucks.
- For the details on construction, refer relevant Duct Construction table.
- For Quality Control, refer to detailed enclosed quality control procedure and form for further details.