1.Corrugated Spiral Rib Pipe 2.Pipe for Road culvert,mining,civil use 3. ... 4.Galvanized and powder coated 5. ISO 9001 Corrugated Spiral Rib Pipe CMP is one kind of flexible, thin-wall, tube ... dipped galvanized≥63μm; Reantiseptic (genearlly coated asphalt) Corrugated Spiral Rib Pipe