The pipe jacking method for the production of seamless steel pipes was proposed as early as 1892 by Heinrich Erhard in Germany. The perforation process of the initial pipe jacking unit was hydraulic perforation method. The steel ingot placed in the mold was extruded into a capillary tube with cup bottom by a vertical hydraulic press, and then the capillary tube was removed by a crane, put down, and the cup-shaped capillary tube was placed on a long mandrel, and the mandrel was pushed to reduce the diameter, reduce the wall and extend the cup-shaped capillary tube through a group of circular die holes with decreasing diameter. The power of deformation is concentrated in the tail of the ejector rod.
It is necessary to remove the rod after the pipe jacking, and then cut the bottom of the cup, which is characterized by low productivity, serious uneven wall thickness, and limited L/D of the steel pipe. At present, this method is only used to produce large caliber (400 ~ 1400m seamless steel pipe). Another method, known as the CPE method, is to produce the tube by the diagonal rolling perforation method, and the method of shrinking the tube at one end to provide the tube for the pipe jacking machine. It can improve the yield and product quality, and restore the vitality for the production of small-caliber seamless steel pipes in the pipe jacking process.
The advantages of pipe jacking method are:
1) Less investment, simple equipment and tools, and low production cost.
2) The extension of the pipe jacking unit is large, and the number of equipment and tools required for rolling similar products can be less.
3) Wide range of variety specifications.
Cangzhou Galaxy Steel Pipe Co., Ltd
Email: sale@galaxy-steel.com
Wechat: LXF13931739696. Whatsapp: 008613931739696
Website: www.friend-steelpipes.com www.cz-steelpipe.com
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