Get a quote on exactly what you need to complete your project. Like this 20 inch CPVC duct pipe. We sell this duct in 10 or 20 foot sections and also have a huge supply of CPVC duct fittings. This CPVC system is great for air handling and has great fire resistance. Get a quote today! Size: 20", Material: CPVC, O.D.: 20.000", Wall: .219", Std Length: 10 or 20 ft. Standards: ASTM D1784