... All these steel pipes are suitable for the industries of oil, natural gas, ship building, chemical, environmental protection, ... pressure liquid delivery, such as water, gas, and oil.piling, etc.ProcessSprial Submerged-Arc Welded TypeSAWStandardAPI 5L,API ... Coal Tar Epoxy,3PE,FBE,Varnish coating,Bitumen coating,Black Oil coating as per customers requirementTestChemical Component Analysis,Mechanical ...