High strength, the inner surface is smooth (friction coefficient is small, the cable is light and smooth, no damage to the cable) , light weight (weight only 1/4 of steel pipe, concrete pipe 1/10 or so, transport is convenient, installation is simple) , not deformation. No galvanic corrosion, non magnetic, suitable for single core cable laying, will not produce eddy current. Good corrosion resistance, high water or seawater erosion performance. Heat resistant, can be used in 120. Insulation, corrosion resistance, no rust, the service life of 50 years or more do not have to maintain, a benefit for life. D=100~200mm Nude packing