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 pipe having a minimum yield strength of 60 ksi. See the table below for the standard available grades.
API 5L Line Pipe Physical Properties
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 pipe having a minimum yield strength of 60 ksi. See the table below for the standard available grades.