Small diameter seamless steel pipe production and production methods are varied, small diameter seamless steel pipe and large diameter seamless tube in the diameter of the size of a different type of steel pipe, because the caliber is relatively small, known as small seamless steel pipe. In the actual production will be because the caliber size will be adjusted caliber size, for small diameter seamless steel pipe is the same, how should we be a small diameter seamless steel pipe size slightly higher? Small diameter seamless steel pipe forming process is the use of special expansion pipe, core mold (commonly known as mandrel) and heating device (commonly known as heating coil), so that the blanks placed in the mold in the push machine driven forward movement, In the process of heating and expanding. The diameter of the tube is smaller than the diameter of the pipe to be obtained, and the deformation of the blank at the inner arc is controlled by the core mold to compensate the other parts where the diameter is reduced due to the expansion. Small diameter seamless steel pipe forming process has a beautiful appearance, uniform wall thickness and continuous operation, suitable for mass production characteristics, thus becoming a carbon steel, alloy steel and stainless steel pipe expansion of the main forming methods. The opposite process is extubation. The thicker steel pipe with the process of stretching into a thin tube, with this process produced by the steel pipe called extubation. Materials are carbon steel, stainless steel and alloy steel.

The groove of the squeeze roller is perforated and gradually becomes larger by the R dimension. When the use of pipe material hot-rolled strip, when there is a negative deviation or moderate strength of steel strip width, the weld will appear quality problems, the light occurs bubble tube, no internal weld reinforcement, heavy cut pipe. It is necessary to constantly check the state of the welding pipe and increase the squeeze squeeze the squeeze. Despite the advantages of high precision HFW steel pipe , but in contrast, straight seam submerged arc welded pipe welding performance is stable, high quality reliability. Spiral submerged arc welded pipe material performance advantage. The transverse yield strength of the pipe is to ensure that the bearing capacity of the pipe is the most important performance index. Spiral submerged arc welded pipe coil raw material sampling general requirements and welding pipe transverse direction, such as the West-East Gas Pipeline second-line demand and the rolling direction of the coil into 30 °. Straight seam steel pipe is not penetrated defect, that is, between the parents of metal or base metal and weld metal between the local incomplete fusion phenomenon. It is usually present in the unilateral weld seam root stress concentration sensitive, greater impact on strength, fatigue performance. The reason is: wire, electrode angle is not correct.

High-frequency induction( HFI ) heating brazing machine advantages: High-frequency induction heating brazing machine biggest advantage: through the principle of induction heating can be one or more metal welding together, as long as the brazing process selected properly, can make the brazed joints without processing and can "seamless", in addition , As long as the appropriate changes in the conditions of brazing, but also conducive to a number of brazing or large quantities of the workpiece at the same time or continuous brazing.  High-frequency induction heating brazing machine in the choice of solder on a wide range, in order to prevent the base metal structure and characteristics of the change, you can use the liquid phase temperature of the corresponding low brazing brazing.  Since the brazing reaction is carried out only at the interface of the number of micrometers to several tens of micrometers, it is generally not related to the deep structure of the base material, and is particularly advantageous between the dissimilar metals, and even between metal and nonmetallic, nonmetallic and nonmetallic Connection. After brazing the brazing seam can do thermal diffusion treatment and strengthen the strength of brazing seam. When the composition of the solder and the base material there is a certain degree of solid solubility, the extension of the holding time can make some of the brazing filler metal to the base material deep diffusion, and ultimately can make the brazing seam disappeared under the microscope.

Industrial production of dsaw pipe often have two options, one option is to use ordinary dsaw pipe, the other option is to have more and better performance of the dsaw pipe. In the long process of production practice, enterprises have generally formed a consensus, that is, with more good features of the dsaw pipe in many ways better than ordinary dsaw pipe. This kind of dsaw pipe is slightly better than ordinary dsaw pipe, mainly from this dsaw pipe has a common dsaw pipe does not have several characteristics. One of the characteristics refers to the high abrasion resistance of the dsaw pipe itself. Pipeline transport of the dsaw pipe often need to bear a lot of friction, in the process of pipeline operation, the material through the pipeline, the elbow in the part will often produce great friction, especially the use of pipeline transmission of solid material, the pipeline in the dsaw pipe where there will be a great impact and friction, these impact and friction is likely to cause a very large damage to the dsaw pipe. Ordinary dsaw pipe is often no way to withstand such shocks and friction, and the use of far up to the ceramic wear elbow can greatly enhance the elbow on the impact and friction resistance. Not only in terms of friction, ceramic wear elbow in the high temperature is also very good. Pipeline in the transmission process, the material and the pipeline between the great friction, this friction will produce high heat, especially in the corners, this high temperature is more obvious. Ordinary dsaw pipe is likely to be under high temperature deformation or damage, and this wear-resistant ceramic dsaw pipe tends to have a relatively high temperature characteristics, the temperature characteristics of this dsaw pipe can withstand this Kind of high temperature, which makes this clock dsaw pipe has a longer life.

In order to reduce the negative error of high-pressure alloy steel pipe , so we have to deal with the existing situation under high pressure alloy pipe negative error method can only be determined first of its size. For example, 8-12 high-pressure alloy steel maximum agreed negative duty value of -7%, accounting diameter d must first determine the negative duty rate K value. K value is too small, will make the inner diameter of the negative error scale is not fully utilized, K value is too large, and can not help but form part of the inner diameter scale beyond the normative rule of the lower limit, fail to achieve the strength of the rules of the rules and judged as unqualified. The existing technical control level, including the average diameter of the inner diameter and the standard deviation, the average of the strength and its standard deviation and so on to determine the K value. K value of 30%, the value of the product diameter d with the nominal diameter of the steel plus the coefficient of 1.274 and the negative error of the utilization of steel, the difference between the negative error of the bar, the nominal cross-sectional area of the steel and then open the square to determine. According to the national standard rules of the horizontal rib distance scale and the product stick before the use of the number of sets of rules, the rules of the German specifications of the rebar roll circumference direction of the number of transverse ribs for the new roller grooving supply basis. Timely to the quality inspection staff to understand the weight of the product value, timely adjustment to ensure that the negative value of the official value of the national standard value.