Q235B spiral steel pipe

(1) raw materials that strip, wire, flux. In the input before going through a rigorous physical and chemical testing.

(2) the head and tail butt joint, using single or double wire submerged arc welding, after rolling into steel pipe using automatic submerged arc welding.

(3) Before forming, the strip is straightened, trimmed, planed, cleaned and delivered to the surface, and then subjected to bending.

(4) The use of electric contact pressure gauge control conveyor pressure on both sides of the press to ensure a smooth strip delivery.

(5) The use of external control or internal roller molding.

(6) The use of weld gap control device to ensure the weld gap to meet the welding requirements, pipe diameter, the amount of the wrong side of the weld gap are strictly controlled.

(7) The internal welding and external welding are using the United States Lincoln welding machine for single-wire or double-wire submerged arc welding, so as to obtain a stable welding specifications.

(8) Welded welds are inspected by ultrasonic automatic continuous online ultrasonic instrument to ensure the coverage of non-destructive testing of 100% spiral welded seam. If there are defects, automatic alarm and spray mark, the production workers so adjust the process parameters at any time, promptly eliminate defects.

(9) using air plasma cutting machine will be cut into single root.

(10) After cutting into a single steel pipe, each batch of steel pipe shall undergo a rigorous first inspection system to check the mechanical properties, chemical composition, melting condition, surface quality of steel pipe and nondestructive testing to ensure that the pipe manufacturing process is qualified After formally put into production.

(11) Where there is a continuous ultrasonic flaw detection mark on the weld, after manual ultrasound and X-ray review, if defective, after repair, it shall undergo non-destructive inspection again until it is confirmed that the defect has been eliminated.

(12) The pipe where the butt-welded steel strip and the butt-welded joint intersect the spiral welded seam are all examined by X-ray television or filming.

(13) Each pipe is hydrostatically tested with a radial seal. Test pressure and time by the steel pipe pressure computer testing device strictly controlled. Test parameters automatically print records.

(14) pipe end machining, the end face verticality, bevel angle and blunt edge to be accurately controlled.