The plate in certain width after slitting line and stripping is unfolded and leveled. Then, they are sent into forming machine. This line adopts total automatic flexible forming in precise control. It adopts roller to bend to the pipe state. The pipe is pre-welded by gas protective welder. Then, the pipe is cut off. Pipe is submerged-arc welded off line to internal and external part. After the hydrotester, pipe end facing and beveling machine, welding seam and pipe body detector, the pipe is qualified. The sizing part adopts quick roller change technology to save the roller changing time.
Straight seam submerged-arc welded pipe mill can be divided into two kinds of model according to the pipe application as following: API model and national standard model.
API model is mainly used for producing the high-grade pipe such as oil, gas delivering and casing pipe in the oil well. These high-grade pipes strictly require the pipe material and pipe quality. This model has X-ray detector, UT detector, hydraulic diameter expander, pipe hydrotester, pipe end expander and other detect equipments and art craft.
National standard model is mainly used for low pressure fluid pipe, structure pipe and other pipes.
Straight seam submerged-arc welded pipe mill has special advantages in the mill. Compared with ERW, the quality and energy consumption of Straight seam submerged-arc pipe is easier to be controlled, and is welded better and low consumption. The welding seam of Straight seam submerged-arc pipe overcomes the shortages of long welding seam and difficult inspection on spiral welding seam after inbuilt. Compared with UOE and JCOE, the investment cost and production cost are low. The quality of Straight seam submerged-arc pipe welding seam is the best in all welding seam technology. Straight seam submerged-arc pipe is the most reliable, and there is no circular interface welding seam on the pipe, which is easy to weld, inspect, maintain and repair. The pipe produced by the mill just covers most pipes which are currently used by oil, gas casing. The mill also has a good market prospect. Annual production capacity is 50,000-100,000 tons.
If there are small differences between Straight seam submerged-arc pipe welding cost and spiral welded pipe cost, nobody will buy spiral welded pipe on high grade pipeline. Straight seam submerged-arc welded pipe will replace fully spiral welded pipe in high grade pipeline, and have a good market prospect.
Straight seam submerged-arc welded pipe mill can be the complement mill for the JCOE mill. Because it is hard and uneconomical for UOE and JCOE to produce the pipes within the diameter range of Φ219～Φ711. There are outstanding advantages such as less production cost and high production capacity. Due to low production capacity and over high price of JCOE mill, which create the serious competition problem, it can make up middle and large diameter in JCOE.
1.Φ325～Φ630 mill，wall thickness: 4-25mm，Max. Material X80
2.Φ325～Φ660 mill，wall thickness: 4-25mm，Max. Material X80
3. Φ355～Φ711 mill，wall thickness: 5-25mm，Max. Material X80