Straight-welded pipes , pipes made of hot-rolled or cold-rolled steel sheets or steel strips are directly welded to the welding equipment. (Because the welded portion of the steel pipe is in a straight line, it is named).

There are many kinds of Q235 straight seam welded pipe quality inspection methods, among which the physical method is also the most commonly used inspection method. Physical inspection is a method of measuring or testing by using some physical phenomena. Inspection of internal defects of materials or Q235 straight seam welded pipes is generally carried out by means of non-destructive testing. The current non-destructive testing includes magnetic flaw detection, ultrasonic flaw detection, radiographic inspection, and penetrant inspection.