The spiral steel pipe is the raw material of strip steel coil plate, and the constant temperature extrusion is formed, and the spiral seam steel pipe is welded by automatic double and double submerged arc welding process. The strength of the spiral steel tube is usually higher than that of straight seam welding pipes, which can be used for the pipe diameter of the pipe with a narrow diameter, and the pipe diameter of the pipe can be different with the same width of billet. But compared with the same length of straight pipe, the weld length is added 30~ 100%, and the yield is low.

Specification of spiral steel pipe:

The commonly used specification is usually divided into: spiral steel pipe SY/T5037-2000 (solid, also called general fluid delivery pipeline with spiral seam submerged arc welding steel pipe), GB/T9711.1-1997 (national standard, also called transport oil and natural gas industry steel pipe delivery condition at the top of some skills: grade A steel pipe (to the current demand strict with GB/T9711.2 grade B steel pipe)), API 5 l (American petroleum institute, also known as the pipeline steel pipe; There are two levels of PSL1 and PSL2, and SY/t5040-92.

Spiral steel pipe features:

1. In the process of molding, the steel plate is deformed evenly, the residual stress is small, and the surface does not produce scratch. Processing spiral steel pipe on the scope of the size of diameter and wall thickness is more flexibility, especially in the production of high grade thick wall tube, especially small and medium caliber thick wall tube has incomparable advantage over other techniques, can meet the requirements of users in the aspect of spiral steel pipe specifications more.

2. Using advanced double-sided submerged arc welding process, the welding can be achieved in a good position, not easy to be wrong side, welding deviation and unsoldered, and easy to control the welding quality.

3. 100% quality inspection of the steel tube, the whole process of steel pipe production is effectively tested and monitored, and the product quality is effectively guaranteed.

4. All the equipment of the whole production line has the function of networking with the computer data acquisition system to realize the real-time transmission of data and the technical parameters of the production process by the central control room.

Welding process of spiral steel pipe:

1. Raw material is strip coil, wire, flux. Before committing, we must pass strict physical and chemical inspection.

2. Connect with steel head and tail, choose single wire or double wire submerged arc welding, then choose active submerged arc welding after winding up.

3. Before forming, strip steel is handled by leveling, trimming and planing, and finishing and handling.

4. Use the electric contact pressure gauge to control the pressure of the cylinder on both sides of the conveyer, ensuring the smooth delivery of the strip.

5. Select external control or internal control roller forming.

6. The weld gap control device is used to ensure that the weld gap is satisfied with the welding demand, the diameter of the pipe, the wrong side and the weld gap are strictly controlled.

7. Both internal and external welding are used for single wire or double wire submerged arc welding, and then the welding quality is achieved.