The National Standard Spiral Steel Pipe is a type of spiral seam steel pipe made from strip steel coils, which is formed through warm extrusion and焊接 using the automatic double-sided submerged arc welding process. The strip steel is fed into the pipe welding machine, passing through multiple roller rolls, gradually rolling up to form a circular billet with an opening gap. The pressure of the extrusion roller is adjusted to control the weld gap between 1~3mm, ensuring the ends of the weld are flush.

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

(2) Steel strip ends are joined using single or double wire submerged arc welding, and automatic submerged arc welding is used for reinforcement after rolling into steel pipes.

(3) Prior to forming, the steel strip is processed through leveling, trimming, edge trimming, surface cleaning conveyance, and pre-bending treatment.

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

(5) Utilize externally or internally controlled roller molding.

(6) The welding gap control device is used to ensure that the welding gap meets the welding requirements, with strict control over pipe diameter, misalignment, and welding gap.

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

(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 marked with paint, allowing production workers to adjust process parameters in real-time and promptly eliminate the defects.

(9) Single steel pipes are cut using an air plasma cutting machine. Standard Spiral Steel Pipe, Manufacturer of Standard Spiral Steel Pipe, Price of Standard Spiral Steel Pipe

(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 condition, surface quality of the pipes, and non-destructive testing to ensure the pipe-making process is qualified before production can commence.

(11) Areas with continuous ultrasonic flaw detection marks on the weld shall undergo manual ultrasonic and X-ray re-inspection. If defects are confirmed, they shall be repaired and re-inspected non-destructively until the defects are eliminated.

(12) All pipes with weld seams of steel strips or T-joints intersecting helical seams have been inspected using X-ray television or filming.

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

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