The spiral steel pipe feeds the strip steel into the welded pipe unit. After being rolled by multiple rollers, the strip steel is gradually rolled up to form a round tube blank with an open gap. Adjust the reduction of the squeeze roller to control the weld gap to 1 ~ 3mm, and make the two ends of the welding port flush.

 1. If the gap is too large, the proximity effect will be reduced, the eddy current heat will be insufficient, and the joint between the welds will be poor, resulting in unfused or cracked.

 2. If the gap is too small, the proximity effect will increase, and the welding heat will be too large, causing the weld to burn; or the weld will form deep pits after extrusion and rolling, which will affect the surface quality of the weld.

 After heating the two edges of the tube blank to the welding temperature, under the squeezing of the squeeze roller, the common metal grains form mutual penetration and crystallization, and finally form a strong weld. If the squeezing force of the spiral steel pipe is too small, the number of common crystals formed is small, the strength of the weld metal decreases, and cracks will occur after the force is applied; if the squeezing force is too large, the molten metal will be pushed out of the weld, Not only reduces the strength of the weld, but also generates a lot of internal and external burrs, and even causes defects such as welding overlap.

 Spiral steel pipe production process characteristics:

 1. The raw materials are strip coil, welding wire and flux. Before input, it must undergo strict physical and chemical tests.

2. Before forming, the strip steel is leveled, trimmed, planed, surface cleaned and conveyed and pre-bent.

3. During the forming process, the steel plate is deformed uniformly, the residual stress is small, and the surface is not scratched. The processed spiral steel pipe has greater flexibility in the range of diameters and wall thickness dimensions, especially in the production of high-steel grade thick-walled pipes, especially small and medium-diameter thick-walled pipes, which have unparalleled advantages in other processes and can satisfy users. More requirements in terms of spiral steel tube specifications.

4. Using advanced double-sided submerged arc welding process, welding can be achieved in the best position, it is not easy to appear defects such as wrong edges, welding deviation and under-welding, easy to control the welding quality.

5. Adopting the welding seam gap control device to ensure that the welding seam gap meets the welding requirements, the pipe diameter, the amount of misalignment and the welding seam gap are all strictly controlled.

6. Perform 100% quality inspection on the steel pipe, so that the entire process of steel pipe production is under effective detection and monitoring, which effectively guarantees the product quality.

7. All the equipment of the entire production line has the function of networking with the computer data acquisition system, realizing the real-time data transmission, and the technical parameters in the production process are controlled by the central control room