General Comparison
Category | Conventional P.V.C. Duct | C.O.D. (Corrugated Optic Duct) |
---|---|---|
Material & Strength |
- PVC: vulnerable to impaction damage - Disconnection: Possibility of dis-connection of connected points of outer duct due to ground compressive load. - Thermal expansion & contraction during the installation period and in service |
- Stand good against impaction damage and no damage risk from freezing temperature. - Strong Concavo-convex shape provides good strength and stays same shape against ground compressive load. - Stays stable from thermal expansion & contraction of duct during or after installation |
Installation |
- Many individual connections: maximum length is 6 meters. - To construct manhole to diverse direction of the line. - Complicated installation work as the insertion of inner ducts is in the second stage after the installation of outer duct. - Causes traffic troubles (jamming) in case of urban installation. - Inner duct may twist in the course of insertion. - Maximum number of inner duct is limited to 3 ducts. |
- No duct connections in-between two manholes up to 500 meters or more. - Single installation process: No need to go through complicated inner duct insertion process owing to readily built-in both outer and inner ducts. - To by-pass minor hurdles and skips un-necessary construction of manhole to diverse direction of line within the radiation of curbing angle. - Increase of duct efficiency by increase of numbers of inner ducts to be inserted up to 5 ducts at approx. same price. - Light weight allows easy handling and transportation. |
Economy | - High construction cost. | - Economic construction cost and time saving |