API SPEC 5 l - 2011 (line pipe specification), is the American petroleum institute, compile and publish, common all over the world.
Line pipe or steel pipeline, is to take out oil, gas or water on the ground, through the pipeline ductules into oil and gas industry enterprises.
Line pipe or steel pipeline including both seamless and welded pipe, the pipe end with flat end, threaded end and socket end; Its connection way as the end of welding, coupling connection, socket connection, etc.
The main material for Gr. B, X42, X46, X56, X65,X70and X80 steel grade.