Basic Information
JCOE is a forming method of straight seam steel pipe, and it is also one of the equipment for producing this kind of steel pipe. It is mainly based on double-sided submerged arc welding production process, products through bending, joint, internal welding, external welding, straightening, flat head and other processes to meet the relevant standards. JCOE steel pipe plays an important role in large-scale pipeline projects, water and gas transmission projects, urban pipe network construction, steel structure construction, bridge piling, municipal construction and urban construction.
Each letter in the JCOE represents a step in the steel pipe forming process:
- J stands for prebending (Jog)
- C indicates that the steel plate is pressed into a C shape
- O stands for the open O shape of the steel plate
- E stands for cold Expanding, a step used to average the stress in the tube and accurately calibrate the type requirements of the tube.
The inner and outer surfaces of the JCOE steel pipe should be smooth, and folding, cracking, delamination, lap welding, broken arc, burning through and other defects with depth exceeding the deviation under the wall thickness are not allowed. The steel pipe forming process is to form the steel plate in the order of J type →C type →O type, and expand the diameter after welding to improve the dimensional accuracy of the steel pipe and improve the distribution of the internal stress of the steel pipe. The main features of the JCOE process include that the molding process is completed on a large press, the molding mold is less wear, the molding mold is light, and the process and products are widely used.
Detailed Information
Specific steps of JCOE process in steel pipe manufacturing
Raw material preparation
Select the appropriate steel plate as the raw material, the steel plate needs to meet certain quality standards.
01
Jogging
The edge of the steel plate is pre-bent at an Angle to facilitate subsequent molding.
02
Molding
The pre-bent steel plate is fed into the forming machine, and the steel plate is pressed into C and O shapes by the press to form the preliminary shape of the steel pipe.
03
Joint
Align the edges of the C and O plates in preparation for welding.
04
Internal welding
Use submerged arc welding technology to weld on the inside of the steel pipe to form an internal weld.
05
External welding
Weld on the outside of the steel pipe to form an external weld and complete the sealing of the entire weld.
06
Straighten:
After the welding is completed, the steel pipe needs to be straightened by the straightener to eliminate the stress and deformation generated during the welding process.
07
Cold Expanding
The steel pipe is expanded by cold expanding machine to improve the dimensional accuracy of the steel pipe and improve the internal stress distribution.
08
Crew cut
The two ends of the steel pipe are cut and polished to make it smooth and easy for subsequent processing or connection.
09
Non-destructive testing
Non-destructive testing such as ultrasonic testing and X-ray testing is carried out on the steel pipe to ensure the quality of the weld and steel pipe.
10
Hydraulic test:
Hydraulic test of the steel pipe to test its bearing capacity and the tightness of the weld.
11
Marking and packaging
Qualified steel pipes will be marked with specifications, lengths and other information, and packed, ready for delivery.
12
Advantages
What are the advantages of the JCOE process compared to other steel pipe?
1. Strong process adaptability: JCOE process can adapt to small batch, multi-variety (specifications) market changes, suitable for the production of different diameters and wall thickness of steel pipes.
2. Low operating cost: Compared with UOE process, JCOE process equipment investment is low, generally 400 million to 500 million yuan, which makes JCOE process has certain advantages in investment cost.
3. High production flexibility: JCOE process is suitable for the production of large diameter, high steel grade products, and for high steel grade products, JCOE process can adapt to different product specifications, providing higher production flexibility.
4. Product quality close to UOE: The quality of steel pipe products produced by JCOE process is close to that of UOE welded pipe, but the price of the production line is much lower than that of UOE unit.
5. Reduce residual stress: Through the cold expanding process, the JCOE process can eliminate the stress generated during the pipe making process and improve the dimensional accuracy and performance of the steel pipe.
6. Excellent welding quality: JCOE process adopts double-sided submerged arc welding technology, high welding quality, short weld, so the probability of defects is small.
7. High accuracy of geometric dimensions: After expanding the diameter, the geometric accuracy of the steel pipe is improved, which is convenient for on-site construction.
8. The weld line is straight: the weld line of the JCOE process is a straight line, which has little impact on the coating quality of the anti-corrosion material.
9. High degree of automation: JCOE process is fully automated, improving production efficiency and welding quality.
10. Strong heat exchange and protection performance: due to the welding under the submerged arc, the heat exchange and protection performance of the JCOE process is relatively strong, and the quality of the welding is relatively high.
