| Detailed Introduction

　　Spiral Pipe Manufacturing Process: (1) Raw materials—steel strip coils, welding wire, and flux—are subjected to rigorous physicochemical inspections prior to use. (2) The ends of the steel strip are butted together and joined by single‑wire or dual‑wire submerged arc welding; after coiling into a pipe, automatic submerged arc welding is used for seam repair. (3) Before forming, the steel strip undergoes leveling, edge trimming, edge planing, surface cleaning and conveying, as well as pre‑bending of the edges. (4) An electrical contact pressure gauge regulates the pressure of the hydraulic cylinders on both sides of the conveyor, ensuring smooth and stable strip transport. (5) Forming is carried out using either externally controlled or internally controlled roller‑type shaping. (6) A weld gap control device ensures that the weld gap meets welding requirements, with strict control over pipe diameter, misalignment, and weld gap dimensions. (7) Both internal and external welds are performed using Lincoln electric welding machines in the United States, employing single‑wire or dual‑wire submerged arc welding to achieve consistent welding parameters. (8) All welded seams are inspected online using continuous ultrasonic automated flaw detection, guaranteeing 100% nondestructive testing coverage of spiral welds. Any defects trigger automatic alarms and spray‑marking, enabling production personnel to promptly adjust process parameters and eliminate defects. (9) Steel pipes are cut into individual lengths using an air‑plasma cutting machine. (10) After cutting into individual pipes, each batch undergoes a stringent first‑piece inspection, evaluating weld mechanical properties, chemical composition, fusion quality, and surface finish, followed by nondestructive testing. Only after confirming compliance with manufacturing standards is the product officially released for production. (11) Areas marked by continuous ultrasonic inspection along the welds are re‑examined manually using ultrasonic and X‑ray techniques; if defects are confirmed, they are repaired and re‑tested nondestructively until complete elimination is verified. (12) Welds at butt joints of the steel strip and T‑joints where they intersect with the spiral welds are all inspected via X‑ray fluoroscopy or radiography. (13) Each pipe undergoes a hydrostatic pressure test, with radial sealing applied. Test pressure and duration are strictly controlled by a microcomputer‑based hydraulic testing system, and test parameters are automatically printed and recorded. (14) End‑face machining ensures precise control of end‑face perpendicularity, bevel angle, and root face.

　　Surface treatment methods for spiral pipes: 1. Cleaning: Solvents and emulsions are used to clean the steel surface, removing oil, grease, dust, lubricants, and similar organic contaminants. However, this method cannot eliminate rust, scale, welding slag, or other surface imperfections; therefore, it serves only as a supplementary measure in corrosion‑preventive production. 2. Tool-based derusting: Steel surfaces are typically abraded using wire brushes and similar tools, which can remove loose or flaking scale, rust, weld spatter, and other surface defects. Manual tooling achieves a Sa2 grade, while power‑driven tools can reach Sa3. If the steel surface is covered with tightly adherent iron oxide scale, tool‑based derusting may be ineffective and fail to achieve the required anchor profile depth for corrosion‑protective coating applications. 3. Pickling: Pickling is commonly performed by chemical or electrolytic means. For pipeline corrosion protection, only chemical pickling is employed, effectively removing scale, rust, and old coatings; it may also serve as a post‑sandblasting treatment. While chemical cleaning can achieve a certain level of cleanliness and surface roughness, the resulting anchor profile is shallow and it poses a risk of environmental pollution. 4. Abrasive blasting/shot blasting: This method uses high‑power motors to drive blast wheels at high speeds, generating centrifugal force that propels abrasive materials—such as steel grit, steel shot, wire segments, and mineral abrasives—onto the pipe surface. Not only does it thoroughly remove rust, oxides, and contaminants, but the intense impact and friction also produce the desired uniform surface roughness. After blasting, the pipe’s surface exhibits enhanced physical adsorption capacity and improved mechanical adhesion between the anti‑corrosion coating and the pipe substrate. Consequently, abrasive blasting is the preferred derusting technique for pipeline corrosion protection. Generally, shot blasting is mainly used for internal pipe surface treatment, whereas sandblasting is primarily applied to external pipe surfaces. How to enhance the stability of spiral pipes: I. Small and medium‑sized structural steel, wire rod, reinforcing bars, medium‑diameter steel pipes, steel wire, and steel ropes may be stored in well‑ventilated sheds, provided they are properly protected with covers on top and pallets underneath. II. Certain small steel products, thin steel plates, steel strips, silicon steel sheets, small‑diameter or thin‑walled steel pipes, various cold‑rolled and cold‑drawn steels, as well as high‑value, corrosion‑prone metal items, should be kept in warehouses. III. Storage areas or warehouses for spiral steel pipe products must be located in clean, well‑drained sites, away from factories or mines that generate harmful gases or dust. The storage area should be cleared of weeds and all debris to maintain a clean environment for the steel. IV. Large structural steel, rails, heavy steel plates, large‑diameter steel pipes, forgings, and similar items may be stacked outdoors. V. In warehouses, corrosive materials such as acids, alkalis, salts, and cement must not be stored together with steel products. Different types of steel should be segregated to prevent mixing and avoid contact‑induced corrosion.

The planning and engineering of spiral welded pipes, as perceived by the customer, is a process that visually communicates a design, plan, or concept. Through labor, previous generations have transformed the world, created civilization, and generated both material and spiritual wealth; at the most fundamental and essential level, this creative endeavor is the act of making. This refers to the workshop plan for producing steel pipes by continuously forming strip steel or steel plates into a spiral shape through cold bending, followed by continuous welding—such as submerged-arc welding.