The difference between seamless steel tube and straight seam welded pipe in hot tension

The difference between seamless steel tube and straight seam welded pipe in hot tension is as follows:
1, The quality of the weld directly determines the quality of the welded pipe, but also the biggest difference between the welded pipe and the seamless steel tube. After the high-frequency welding of straight seam welded pipe, the carbon in the straight seam cannot be eliminated. The weld seam and the parent body are only joined together. They are not completely melted and cannot stand the test of time and high pressure. After the high-frequency welding, the hot tension reducing steel pipe also undergoes an overall heating of 800 degrees and the whole annealing, and then carries out the open-change treatment. After this series of processes, the properties of the weld and the mother structure are the same and completely melted into one body. , well done from the seam to the seamless transition.

2, The difference in the process caused the difference in product quality, hot tension reducing steel pipe in the high-frequency welding also performed a straight seam welded pipe did not carry out the process ------ online clearance of internal and external burrs. The presence of burrs can affect the flow of fluid in the tube. The burrs block the normal flow of fluid and create vortices. According to the principle of fluid mechanics, the local pressure of the weld seam will inevitably increase, and the coefficient of insurance of the welded pipe will be greatly reduced due to the non-uniform force. In the production process of the hot tension reducing steel pipe, the risk of the burr is fully taken into consideration, and the limited burr removal is performed. The wall thickness is uniform, and there is no difference in appearance with the seamless steel tube. So from this point of view, the hot tension reducing steel pipe also completed the transition from seam to seam.

Of course, the difference between the two is not limited to the above two points, but it is enough to show that there is still a big difference between the straight seam welded pipe and the hot tension reducing steel pipe. The latter, on the basis of straight seam welded pipes, has undergone a series of new technologies such as on-line removal of internal and external burrs, overall heating, and deformation, which has enabled it to make a qualitative leap forward and can be commonly used in the medium- and high-pressure fields. Welded pipes can only be limited to water gas transport in low pressure environments.