... Q23 4.Galvanized and powder coated 5. ISO 9001 Corrugated Spiral Rib Pipe CMP is one kind of flexible, thin-wall ... overhaul, temporary sidewalk2. Municipal works and construction: utility tunnel, optical cable protection, drainage pitch3. Water conservancy: culvert, passage, bridge, pilotage pipeline ... : hot dipped galvanized≥63μm; Reantiseptic (genearlly coated asphalt) Corrugated Spiral Rib Pipe