Typical Specification -Section 15891

2.01 Underground Vehicle Exhaust Duct

      A. Underground fiberglass duct and fittings as shown on the drawings shall be UnderDuct V E Duct by Monoxivent. Duct and fittings shall be made with a fire retardant vinyl ester resin that is corrosion resistant to carbon monoxide gas and engine exhaust at 325 dg F. Duct shall meet the requirements of a Class 1duct per UL 181 throughout the laminate.  Linings or coatings of a different material are not acceptable.

          B. Duct should be shop fabricated as much as possible limiting the number of field joints. Joints will be made using the butt and wrap wet lay up method. Provide electronic shop drawings showing system layout and field joint locations.

        C. Duct will be filament wound with a “C’’ veil interior and exterior layer. Wall thickness and fitting dimensions will be in accordance with ASTM D-3982, NBSPS15-69 and SMACNA’s Thermoset FRP Duct Construction Manual.

        D. UnderDuct VE duct should be laid out in a graded trench with good drainage on a 4’’ bed of pea gravel or sand. Next the field joints should be laminated and exhaust outlets installed per manufacturer’s instructions. Duct system should then be buried and compacted following manufactures instructions. Do not allow vehicular traffic over the buried duct.