Pipeline: It refers to the transportation of oil, gas, or water extracted from the ground to oil and gas industrial enterprises through pipeline. Pipeline Pipes include seamless and Welded Pipes, with flat ends, threaded ends, and socket ends; The connection methods include end welding, coupling connection, socket connection, etc. Purpose: Used for gas, water, and oil transportation in the petroleum and natural gas industries API SPEC 5L-2011 (Pipeline Pipe Specification) is developed and published by the American Petroleum Institute and is widely used worldwide. The main materials of this pipe are L245, L290, L360, L415, L480, and GR B. X42, X46, X56, X65, X70, X80, X100 and other steel grades.