Features: 1.The pipe high strength ,resist compression,resist curve based on the ring-corrugated structure ; 2.High flow volume,low clash,no grim based on the smooth inwall 3.Anti-corrosion, Non-toxic , non-pollution,high stability based on the material; 4.Light weight ,install easy,low cost based on the middle empty structure ; 5.Working temperature:-60 degree  to +45 degree 6.Long life: 50 years at least 7.The material is 100% recycle .save natural resource & Protect environment;