Flat-oval spiral duct is machine formed round spiral duct. The straight sections of the long sides are stretched tout and perfectly flat. The flat oval shape is specifically designed for low head room and restricted space locations which can't accept round duct.

Spiral Duct work systems in both round and flat-oval shape have many advantages. Some of the major advantages include

• Light weight spiral reinforced walls.
• Smooth streamline internal surfaces giving low friction loss and no turbulence.
• Long runs in continuous lengths.
• Simple joining technique.
• matted fittings of consistent size.
• Reduced space requirement in height or depth.

Specifications:

• Thickness: 24 G to 20 gif Thickness of flat-oval spiral ducts as per SMACNA "HVAC Duct Construction Standards" - 1985.
• Length:
  4, 8, 10 and 12 ft. length
• Material:
  Galvanised steel, mild steel (CRCA), Aluminium, Stainless Steel etc.
• Surface Constructions:
  Plain or Corrugated (to increase the radial rigidity of the duct by 300%)

Pre-insulated Double-walled Flat-oval Spiral Duct Systems

Thermal/Acoustic Insulation
A double-walled insulated Flat-oval Spiral Duct consists of an external pressure tight metal shell, a 12.5/25/50 mm thick of fiberglass/mineral wool/puf insulation and internal plain protective metal liner for thermal insulation or perforated metal inner liner for acoustic insulation.

Thermal

• Outer metal pressure shell
• Insulation blanket
• Internal smooth metal liner.

Acoustic

• Outer metal pressure shell
• Insulation blanket
• Internal perforated metal liner.
• Fiber glass tissue

Seven Star flexible ducts made of 2ply/3ply/4ply multi-layered Aluminium Polyester, Metalised Polyester, etc. foils bonded together by quality adhesive and reinforced with high carbon corrosion-proof spring wire. Seven Star Flexible ducts are non-flammable and more efficient. Materials used are compliant to AWTA Fire Standards.

Specifications:

• Available in various I.D. ranging from 100 mm to 500 mm (4" to 20")
• Supplied in Standard length of 10 meteres each
• Available bare or insulated.

A metered dose of Poly urethane foam (PUF) is injected in the factory, in the regular space between carrier pipe (Chilled water pipe) and the outer jacket. The PUF expands and, upon setting, forms a homogenous insulation around the carrier pipe. The combination of pipe, insulation and jacket together is called pre-insulated pipe.

Specifications:

• Insulation
  Material : Polyurethane Foam
  Thickness: 25 mm onwards to suit application
  Density : Standard 36kg/m³. Other densities on specific request.
• Fluid Temp. Range : -20`c to 120`c
• Sizes : For carrier pipes 19mm onwards
• Pre-insulated Pipe Length 6m
• Outer Jacket
  Metallic : GI/AI/Stainless Steel
  Non-metallic : HDPE/PVC

Pre-Fabricated Rectangular Ducts from SEVEN STAR for hassle-free and faster completion of projects

The Manufacturing Facility

• Uncoiling, Leveling and Notching
• Lockformer for Longitudinal joints
• TDF flanger for transverse connectors
• TDF Hydraulic folder for L, U & Boxed ducts

The SEVEN STAR Integrated Ducting System

• The Longitudinal Joints will be factory formed and sent to site in L shaped sections for easy transportation, site handling and storage and to facilitate easy assembly at site. Boxed up ducts also available on request.
• The Transverse Connectors are C cleats, S cleats, Standing S cleats, TDF Flange (Integral Rolled on Duct Flange), 35mm Mate Flange, Angle iron/GI Flange.
  • C, S and Standing S cleats will be cut to size and sent loose to drive at site.
  • TDF corner flange will be fixed on the L shaped contour. The corner flange along with the requisite amount of C Clamps for flange locking will be sent separately.
  • Slip on mate flange will have one corner flange fixed to duct and sent in L shape. The corner flanges along with the requisite number of C clamps for mate lange locking will be sent separately.
• Bolts, Nuts, Gaskets, Sealants are also supplied on request to ensure the system is complete. This arrangement ensures that the duct can be boxed up and erected with simple hand tools.

Seven Star Semi rigid ducts are machine formed in a continuous spiral from Aluminium strips, creating an airtight tube which can easily be cut to length by hand to conform to a desired duct route, without altering its full circular cross section.

Specifications

• Type - Plain unisulated
• Material - Aluminium
• Maximum Velocity - 20 meters/sec
• Maximum Positive Pressure - 1.5 kPa
• Maximum Negative Pressure - 1.5 kPa
• Sizes - 75mm to 300 mm diameter

Today, more and more companies are switching from rectangular to spiral rigid duct work. Why is this? What advantages do spiral systems have over rectangular? The answer is simple.

• Energy efficient
• Cost less to install
• Often requires less space
• Need less hangers
• Operation cost lower
• More noise free
• Installation simplified
• Cleaning less complicated
• Airlow measurement easier
• Light in weight

The perimeter of round ducting system is less by 20% or more of same cross section of rectangular ducting. Hence, the area of ducting and insulation required is less by the same percentage.

Applications

• Air conditioning (including hight pressure and velocity air distribution systems)
• Ventilation (Industrial & Tunnel)
• Warm air heating
• Fume and dust extraction
• Pneumatic conveying
• Exhaust and air intake pipes
• Humidifiation.

Specifications
Thickness:

• 0.40mm(28G) to 1.6mm (16G)
• Thickness of Spiral ducts as per SMACNA (HVAC Duct construction standards)

Diameter: 75 mm to 1600 mm
Length: Unlimited
Material: Galvanised steel, Aluminium, Mild Steel (CRCA), Stainless, etc.
Surface Construction: Plain or Corrugated ( to increase the rigidity of the ducting by 300%)

Pre-insulated Double-walled Spiral Duct Systems.
A. Thermal Insulation:
A double-walled thermal insulated spiral duct consists of an external pressure-tight metal shell, a 12.5/25/50mm thickness of fiberglass/mineral wool/PUF insulation and an internal protective metal liner.

Advantages

• Double-wall fire protection
• No Sheet metal screws in the air stream.
• Lower friction loss
• Improved appearance
• Speed installation
• No fibers in the air stream
• Protection from external damages.

B. Acoustic Insulation:
A double-walled acoustic insulated spiral duct consists of an external pressure-tight metal shell, a 12.5/25/50 mm thickness fiberglass/mineral sool insulations and an internal perforated protective metal liner and fiberglass tissue between the perforated liner and insulation material. In addition to the above advantages this systems is having the advantage of High Sound transmission loss.

Duct Fittings:
Duct Fittings, standing seam Elbows, Reducers, End caps, Offsets, etc. are manufactured on high speed machines while maintaining the hight dimesional accuracy.

Seven Star Plennum Boxes:

Type:

• Available in Single & Double Skin

Colors:

• Available in any color of your choice making it suitable for use with all Air handling Units.

Construction:

• Available with GI/SS sheets
• Extruded Aluminium Profile frames
• Available with/without Thermal break
• Sealant provided for Zero leakage
• 25/40/50 mm thick Polyurethane foam insulation