1.Corrugated Metal Pipe Culvert 2.Specifications can be ... fields of Ribbed Unitary Steel Reinforced Corrugated Metal Pipe1.Highway and railway: culvert, passage, bridge, tunneling overhaul, ... tunnel, optical cable protection, drainage pitch3. Water conservancy: culvert, passage, bridge, pilotage pipeline, drainage pipeline4. Coal ... highly attention.Thanks.certificates Corrugated Metal Pipe Culvert