Spiral Welded Pipe: This involves rolling low-carbon carbon structural steel or low-alloy structural steel strips into a billet at a specific helical angle (referred to as the forming angle), and then welding the pipe seam to create the pipe. It allows for the production of large-diameter steel pipes using narrower strips. The specifications are indicated by outer diameter * wall thickness. The welded pipes must meet the requirements for hydrostatic testing, tensile strength of the weld seam, and cold bending properties.

Compliance Standards

SY5036-83 spiral seam submerged arc焊接钢管 for pressure fluid conveyance is mainly used for oil and natural gas pipelines; SY5038-83 spiral seam high-frequency焊接钢管, which utilizes high-frequency butt welding, is designed for pressure fluid conveyance. These steel pipes have strong pressure-bearing capacity, good plasticity, and are easy to weld and shape; the general low-pressure fluid conveyance spiral seam submerged arc焊接钢管 SY5037-83, produced by double-sided automatic submerged arc welding or single-sided welding, is used for conveying water, coal gas, air, and steam in general low-pressure fluid applications.

Common standards for spiral steel pipes generally include: SY/T5037-2000 (Ministry Standard, also known as Spiral Submerged Arc Welded Steel Pipe for General Fluid Transportation), GB/T9711.1-1997 (National Standard, also known as Technical Conditions for Delivery of Steel Pipes for Oil and Gas Industry Transportation - Part 1: Grade A Pipes (for stricter requirements, see GB/T9711.2 Grade B Pipes)), API-5L (American Petroleum Institute, also known as Pipeline Steel Pipe; which is divided into two levels: PSL1 and PSL2), and SY/T5040-92 (Spiral Submerged Arc Welded Steel Pipe for Piling).

Material

Q235A，Q235B、16Mn、20#、40#

Specs

Spiral Pipe Φ219-2320x6-22mm

Application

Spiral-welded pipes are primarily used in domestic applications such as water supply projects, petrochemical industry, chemical industry, power industry, agricultural irrigation, and urban construction. They are used for liquid transportation: water supply and drainage. For gas transportation: coal gas, steam, liquefied petroleum gas. For structural purposes: pile driving pipes, bridges; wharfs, roads, and pipes for building structures.

Production Process

Spiral-welded pipes are also a type of welding pipe equipment, generally boasting higher strength than straight seam-welded pipes. They can produce larger diameter pipes with narrower billets and can also produce pipes of different diameters with the same width billets. However, compared to pipes of the same length with straight seams, the weld length increases by 30~100%, and the production speed is slower. Therefore, smaller diameter pipes mostly use straight seam welding, while larger diameter pipes usually employ spiral welding.

Spiral Steel Pipe Production Process: It is a spiral seam steel pipe made from strip steel coils, formed by normal temperature extrusion, and welded using the automatic double-spiral double-sided submerged arc welding process.

1. Raw materials include steel coils, welding wire, and flux. All must undergo stringent physical and chemical inspections prior to use.

2. Steel strip ends are joined using single or double wire submerged arc welding, followed by automatic submerged arc welding 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 external or internal roll forming.

6. Utilize a welding gap control device to ensure the welding gap meets the welding requirements; strict control is applied to pipe diameter, misalignment, and welding gap.

7. Both internal and external welding processes use Lincoln welding machines for single or double wire submerged arc welding, ensuring stable welding specifications.

8. All weld seams are inspected with online continuous ultrasonic flaw detectors, ensuring 100% coverage of spiral welds with non-destructive testing. In the event of defects, an automatic alarm is triggered and marking is applied, allowing production workers to adjust process parameters in real-time and promptly eliminate the defects.