16～50OD

As the density of material PP merely is 0.9g/cm3 , modulus of elasticity basically is twice than that of material HDPE（modulus of elasticity of PP-H could reach 1700-1800Mpa）,therefore, standard requirement of the double wall corrugated pipe could be met with less costs relatively. Compared with HDPE pipe, PP pipe could usually save 30%-50% raw material when reaching the same ring stiffness. Moreover, the ring stiffness of PP double wall corrugated pipe is easily more than 10 KN/m2

By viewing of the widespread use of HDPE double wall corrugated pipe and MRP spiral corrugated pipe, HDPE double wall corrugated pipe is mainly used with specification below Φ800, while MRP spiral corrugated pipe is mainly used with specification aboveΦ1000. With PP double wall corrugated pipe is known gradually, it is predicted that Φ800-Φ1500 drain pipe and blow-off pipe will be mainly used with PP pipe, because this kind of pipe is with features of low production cost, fast production speed, easy for construction, easy to recycle etc.