... 6MPa, 0.8MPa, 1.0MPa, HDPE double wall corrugated pipeHDPE density polyethylene double wall corrugated pipe is a new type of light- ... material pipes.According to different ring stiffness grades,HDPE double wall corrugated pipe falls into S1(ring stiffness≥4KN/m2)and ... shallow and too deep. Specifications are as below (nominal inner diameter):200mm, 225mm, 300mm, 400mm, 500mm, 600mm, 700mm ,800mm ...