Specifications 1, Structure: epoxy powder, copolymer gel, PE anti-corrosion layer 2, Applications: for water, oil, ... : 30 daysSpecifications 1, Structure: epoxy powder, copolymer gel, PE anti-corrosion layer2, Applications: for water, oil, natural gas transmission ... tubeGB/T8163≥DN200spiral welded steel pipeGB/T9711.13 PE anti corrosion layersSY/T 0413-2002itemRequest standardminimum thickness of ...