API 5L Grade B Pipe| API 5L Carbon Steel Pipe| API 5L …
API 5L Grade B Line Pipe Physical Properties. Line pipe grade designations come from API Spec 5L Specification for Line Pipe. Standard Line Pipe has grade designation A and B. Stronger grades have the designation X followed by the specified minimum yield strength of the pipe steel, measured in kilopounds per square inch (abbreviated ksi), e.g. X60 for …