Kunming Spiral Pipe

Spiral tube production process:

(1) Raw materials include steel coils, welding wire, and flux. All must undergo strict physical and chemical testing before use.

(2) Steel strip ends are joined using single or double wire submerged arc welding, followed by automatic submerged arc welding for patching after rolling into steel pipes.

Prior to forming, the steel strip undergoes leveling, trimming, edge dressing, surface cleaning conveyance, and pre-bending processing.

(4) The electrical contact pressure gauge controls the pressure of the hydraulic cylinders on both sides of the conveyor, ensuring smooth steel strip transport.

(5) Utilize external or internal roll forming.

(6) Employ a weld gap control device to ensure the weld gap meets welding requirements; the pipe diameter, misalignment, and weld gap are all strictly controlled.

(7) Both internal and external welds are performed using Lincoln welding machines for single or double wire submerged arc welding, ensuring stable welding specifications.

(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 adjust process parameters accordingly to promptly eliminate any defects.

(9) Cut steel pipes individually using an air plasma cutting machine.

(10) After cutting into individual steel pipes, each batch must undergo a stringent initial inspection process, checking the mechanical properties of the welds, chemical composition, fusion status, surface quality of the pipes, and undergo non-destructive testing to ensure the pipe manufacturing process is qualified before production can commence.

(11) Areas with continuous ultrasonic flaw detection marks 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 welds of strip steel and at the T-joints intersecting helical welds have been inspected with X-ray television or filming.

Each steel pipe undergoes hydrostatic testing with radial sealing. The testing pressure and time are strictly controlled by the steel pipe hydraulic pressure microcomputer detection device. Test parameters are automatically printed and recorded.

(14) Machining at the pipe end ensures precise control of the perpendicularity of the end face, bevel angle, and burr.