General Comparison Table of COD to Conventional Duct
|Category||Conventional P.V.C. Duct||C.O.D. (Corrugated Optic Duct)|
- 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
- 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|