|Roladuct Spiral Flat-Oval duct is machine-formed from Roladuct Round Spiral Tubing. The flat-oval shape is specifically designed for low head room and restricted space locations which cannot accept round duct.
Spiral Flat-Oval Compared with Rectangular Duct
The Spiral Flat-Oval has considerably less flat surface than rectangular duct. If the springy structure of flat-oval is adequately dampered. It has less surface susceptible to vibration. Thus, properly designed flat-oval duct can be superior in performance to rectangular duct.
The characteristics of flat-oval duct parallel those of circular-shaped duct closely enough that slip-joint couplings can be used. Slip-join couplings provide easier sealing against air leaks at the joints, a significant improvement over other types of duct connections.
There is an unfortunate tendency to make a surface application of sealer over a joint and assume that this is a permanently satisfactory solution to the sealing problem. This is not the case, as surface-applied sealing has provided that the sealer must be protected by metal, such as within a slip-joint, in order to be considered a permanent seal.
The Spiral Flat-Oval coupling and joint permits the use of the same experience-proven materials and technique for sealing that have been so successful in circular duct joints.
Under certain size and pressure conditions, both flat-oval and rectangular duct must be braced and reinforced against deflection.
Flat-Oval Duct Design
The design of a duct system utilising flat-oval duct follows the same procedures used with rectangular duct.