Process the sides of the two plates into the required form at one time, steel plate edge milling machine: machine the two sides of the plate used for pipe making, and make the parallelism of the two plates within the specified tolerance range, to manufacture high-precision Steel pipes are prepared. Make the edge of the steel plate have the same radius of curvature as the radius of the formed steel pipe. Steel plate pre-bending machine: pre-bends the edge of the steel plate with welded grooves on both sides processed by the milling machine. Prevent excessively long straight edges from forming steel pipes formed by the forming machine, and ensure the roundness of the steel plate. , Fully automatic steel pipe forming machine: complete the bending and forming of various metal sheets. Carry out further seams and pre-welds.
Steel pipe pre-welding machine: The forming machine will form a qualified open tube blank to prepare for internal and external welding. The welding trolley transports the workpiece and walks along the track.
Double-wire internal welding machine: used for automatic submerged arc welding of large-diameter straight seam steel pipes, and cooperates with the main machine to realize welding of workpieces. The welding trolley transports the workpiece and walks along the track.
Double-wire external welding machine: used for automatic submerged arc welding of straight seam steel pipes, and cooperates with the main machine to realize welding of workpieces. To change the roundness of steel pipe.
Steel pipe finishing machine: apply strong pressure from the outside section by section to the long round pipe with poor roundness to make it meet the relevant specifications and use requirements.
Gantry mobile sensory straightening machine: used for straightening steel cylindrical tubes.
Straight seam steel pipe flat head chamfering machine: chamfer the end of the straight seam steel pipe according to the specified blunt edge and bevel angle. Improve the dimensional accuracy of steel pipes.
Steel pipe expanding machine: stress relief. Check the steel pipe for penetration defects under the specified pressure.
3000T hydrostatic testing machine: conduct hydrostatic tests on welded pipes. Eliminate welding stress and forming stress, to ensure the performance of steel pipes. It can detect longitudinal and transverse defects and heat-affected zone layer defects.
Line wave testing equipment: conduct 100% line wave nondestructive testing on all welds.
With the continuous improvement of rural environmental protection requirements, with the development of my country's oil and gas industry. In particular, the layout of the energy pipeline network has led to an increasing demand for straight seam submerged arc welded steel pipes and an increasing demand for the localization of large-diameter straight seam steel pipes. The West-East Gas Pipeline Project is a national standard project, requiring 1.82 million tons of large-diameter straight seam steel pipes, of which 820,000 tons are large-diameter straight seam arc welded steel pipes, and only a part of them are domestic steel pipes.
Key points of processing technology for large diameter straight seam steel pipe:
Rebar thread processing
① The wire head, tooth shape, and pitch of the processed steel bar thread are consistent with the tooth shape and pitch of the connecting sleeve and are qualified by the matching gauge.
② When processing steel bar threads, water-soluble cutting lubricants should be used; when the temperature is lower than 0°C, 15%-20% sodium nitrite should be mixed in, and engine oil should not be used as lubricating fluid or no lubricating fluid sleeve Silk.
③ The operator should check the appearance of the steel wire heads one by one and make an operator mark.
④ For steel wire heads that have passed the self-inspection, 10% of the processing volume of each specification shall be randomly inspected, and no less than 10. If one fails, the entire processing batch shall be inspected. The head should be reprocessed and can be used after passing the re-inspection.
⑤ The wire heads that have passed the inspection should be protected and put on protective caps, classified according to specifications, and ready for use.
Hunan Gaoxing Steel Development Zone, No.1888 Purui South Rd, Wangcheng District,Changsha, Hunan, China