8) All welded seams are inspected by an online continuous ultrasonic flaw detector, ensuring full coverage of non-destructive testing for spiral welds. In case of defects, an automatic alarm is triggered and marking is applied. Production workers then adjust process parameters accordingly to promptly eliminate the defects.
(9) Cut steel pipes individually using an air plasma cutting machine.
(10) After cutting into individual steel pipes, each batch must undergo a rigorous initial inspection system. This includes checking the mechanical properties of the welds, chemical composition, fusion condition, surface quality of the pipes, and undergoing non-destructive testing to ensure the pipe-making process is qualified before it can be officially put into production.
(11) Areas marked with continuous ultrasonic flaw detection on the welds are subject to manual ultrasonic and X-ray re-inspection. If defects are confirmed, they are repaired and re-inspected non-destructively until the defects are eliminated.
(12) All pipes at the locations of steel strip welds and T-joints intersecting helical welds have been inspected with X-ray television or film.
(13) Each steel pipe undergoes hydrostatic testing with radial sealing pressure. Both the test pressure and time are strictly controlled by the water pressure micropressure detecting device of the steel pipe. Test parameters are automatically printed for record.
(14) Precision machining at the pipe end ensures accurate control of the end face perpendicularity, bevel angle, and burr.