... faults after external damage.2. HDPE Sand Delivery Pipe has good flexibility, tensile strength and elastic, pipe extrusion, pack, it doesn't break ... after internal and external force impact, Plastic pipe can be directly connected ... is low, high efficiency, safer, and more convenient.HDPE pipe types: SDR33, SDR26, SDR21, SDR17, SDR13.6, SDR11 ...