DSAW
Definition
DSAW steel pipe is a steel pipe manufactured using double-sided submerged arc welding technology, which involves two welding processes to create a strong weld in the direction of the length of the steel pipe.
Peculiarity
1. High strength weld:
DSAW steel pipe has high welding quality, high weld strength, and can withstand greater pressure and tension.
2. Corrosion resistance:
DSAW steel pipe surface after sandblasting, rust removal and other treatment, can effectively prevent the corrosion of steel pipe surface.
3. High dimensional accuracy:
The manufacturing process of DSAW steel pipe has high precision and high dimensional precision, which can meet the requirements of various projects.
4.Long service life:
DSAW steel pipe welding quality is high, the surface is treated, long service life, can meet the requirements of various projects.
Advantage
1.High production efficiency:
The DSAW steel pipe manufacturing process has higher production efficiency compared to other steel pipe manufacturing processes.
2. High welding quality:
DSAW steel pipe adopts double-sided submerged arc welding technology, high welding quality and high weld strength.
3. Wide range of application:
DSAW steel pipe is suitable for various engineering fields and can meet various engineering requirements.
Application field
DSAW steel pipe is widely used in oil, natural gas, chemical industry, electric power, water conservancy and other fields. In oil and natural gas pipelines, DSAW steel pipe is an important pipeline material, which can withstand high pressure, high temperature, corrosion and other harsh environments.
Common Problem
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What are the advantages of DSAW steel pipe compared with traditional steel pipe?
1. High strength weld:
- DSAW steel pipe adopts double-sided submerged arc welding technology, high weld quality, good weld fusion, can withstand greater pressure.
2. High productivity:
- DSAW steel pipe production process has a high degree of automation, fast welding speed, high production efficiency, especially suitable for mass production.
3. Good impact toughness and low temperature performance:
- Because the welding process is carried out under the flux layer, the air pollution to the weld pool is effectively isolated, and the welding defects such as porosity and slag inclusion are reduced. The weld has good impact toughness and low temperature performance.
4. High dimensional accuracy:
- DSAW steel pipe has high dimensional accuracy, high internal and external welding surface coincidence accuracy, and high steel pipe geometry accuracy.
5. Low welding defect rate:
- DSAW steel pipe has short weld passage, low probability of welding defects, small residual stress, and less consumption of auxiliary materials.
6. Energy saving and environmental protection:
- Compared with traditional welding methods, submerged arc welding of DSAW steel pipes produces less smoke and harmful gases, which is conducive to environmental protection and worker health.
7. Wide adaptability:
- DSAW steel pipe welding parameters such as current, voltage, welding speed can be precisely controlled, suitable for different materials, different wall thickness of steel pipe welding, with strong adaptability and flexibility.
8. Reduce costs:
- DSAW steel pipe's high efficiency production line and low defect rate reduce the consumption of raw materials and energy, reducing production costs.
9. Improve pipeline safety:
- In high-risk areas such as oil and gas transmission, high-quality welds can effectively prevent leaks and ensure safe pipeline operation.
10. Extend service life:
- Excellent weld quality improves corrosion resistance and fatigue resistance of the pipeline and prolongs the service life of the pipeline.
These advantages make DSAW steel pipes an ideal alternative to conventional steel pipes in many engineering applications, especially where high strength, toughness and dimensional accuracy are required.
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What is the welding process of DSAW steel pipe?
1. Board probe:
- The production line first conducts a full plate ultrasonic inspection of the steel plate to ensure the quality of the raw materials.
2. Edge milling:
- Double-sided milling of two longitudinal edges of the steel plate by automatic edge milling machine to achieve the plate width, plate edge parallelism and groove shape required for processing.
3. Pre-bending edge:
- Pre-bending the edge of the plate with a pre-bending machine, so that the edge has the required curvature, in preparation for forming, welding and expanding processes.
4. Molding:
- JCO forming method is progressive multi-step molding, the steel plate by the numerical control system to achieve the ideal round, all parts of uniform deformation, small residual stress, uniform distribution.
5. Pre-welding:
- The pre-welder performs rapid joint pre-welding of the open steel pipe to lay the foundation for ensuring the quality of the internal and external multi-wire submerged arc welding. High power continuous active gas shielded arc welding (MAG) is used to ensure the quality of pre-welding.
6. Internal welding:
- Internal welding adopts longitudinal multi-wire submerged arc welding on the inside of the steel pipe, which is characterized by high production efficiency, low porosity and slag inclusion rate, small crack tendency, good joint mechanical properties, and easy control of weld geometry.
7. External welding:
- External welding adopts longitudinal multi-wire submerged arc welding on the outside of the straight seam submerged arc welded steel pipe.
8. Ultrasonic inspection:
- 100% UT automatic flaw detection for the inner and outer welds of the straight seam welded pipe and the base material on both sides of the weld.
9. X-ray inspection:
- 100% X-ray industrial TV inspection of internal and external welds, using image processing system to ensure the sensitivity of the inspection.
10. Expanding diameter:
- The expanding machine can expand, round and straighten the full length of the straight seam submerged arc welded steel pipe to improve the geometric accuracy of the steel pipe and improve the distribution of the internal stress of the steel pipe.
11. Hydraulic test:
- Hydraulic testing machine to expand the diameter of the steel pipe after the water pressure test, to ensure that the quality of steel pipe meet the requirements.
12. Chamfering:
- Chamfering machine for pipe end bevel processing, to achieve the required pipe end bevel size, to ensure the quality of steel pipe butt welding.
13. Ultrasonic inspection again:
- Carry out UT flaw detection on the weld and the base material on both sides one by one again, and check the defects that may occur after the expansion and water pressure of the straight seam welded pipe.
