In the past five years, the development trend of stainless steel welded pipe has been relatively good. Regardless of scale, quality, and production technology, there have been relatively great progress, especially its demand field is gradually expanding. In addition, as the stainless steel welded pipe technology becomes more mature, it can gradually replace stainless steel seamless pipes in many applications, such as: heat exchanger equipment tubes, medium and low pressure boiler tubes, and so on.
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Production characteristics of stainless steel welded pipe: light production equipment, low investment, fast construction speed, simple welding method, wide product specification range, high dimensional accuracy, small wall thickness deviation, smooth surface and high yield rate. In the case of mass production, the cost of welded pipe is more than 20% lower than that of seamless pipe. In recent years, the “welding-cold rolling” process adopted in China to produce stainless steel tubes is to use cold-rolled coils to slit and shape according to the specifications, weld them into tubes by multi-gun argon arc welding machine, and then cold-roll (pull) to make The performance indexes of the weld can be basically the same as the base material, and the product quality is significantly improved. Therefore, the advantages of replacing stainless steel seamless pipes with stainless steel welded pipes are becoming more and more obvious.
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Advantages of stainless steel welded pipe production: First of all, in the production process of stainless steel welded pipe, the pipe body will be evenly squeezed, and then after online bright solid melting annealing, the surface becomes very smooth, and the smooth surface is not easy to scale, with anti-scaling Features. This is both conducive to heat dissipation and does not require frequent cleaning, saving time, effort and money. Secondly, the welded pipe is a deep-processed product of the plate, and its advantage of uniform wall thickness is unparalleled. At the same time, it can be arbitrarily sized, with high accuracy. Thirdly, the stainless steel material has the characteristics of corrosion resistance and long service life.
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Current status of stainless steel welded pipe products: The production capacity of China's industrial stainless steel welded pipe does not match the domestic market demand. Most of the existing stainless steel welded pipe unit's process equipment is not complete, such as lack of heat treatment and online testing equipment, so that the production capacity of the unit Give full play, generally can only produce general decorative tubes, and the market of medium and low-grade stainless steel decorative welded tubes exceeds the supply; the higher standard industrial welded tubes, such as chemical machinery tubes and heat exchanger tubes, are only a few manufacturers It can be produced, but the production capacity is seriously insufficient. Hangao Tech (SEKO Machinery) SZG-JM series precision stainless steel welded pipe production line solves this problem. The entire production line includes a series of processes such as forming welding, inner welding seam leveling, welding seam grinding, bright annealing, and sizing cutting. The intelligent electronic control system coordinates the operation of each part, improving efficiency while reducing energy efficiency.
Can the welded pipe act on the heat exchange equipment?
1. Higher standard product tubes are possible
The heat exchanger tube is an indispensable part of the tube-and-tube heat exchange equipment, and the heat exchanger tube is generally selected according to the pressure and the fluid medium. Now one of the misunderstandings in the selection of heat exchanger tubes on the market is that stainless steel welded tubes cannot be used as heat exchanger tubes, but GB / 151-1999 clearly stipulates that stainless steel welded tubes can be selected when the tube side pressure is ≤6.4MPa. Especially now that the production process of stainless steel welded pipes is now very mature, it can fully meet the needs of general heat exchanger tubes, and shows its unique advantages.
2. The production process is mature, austenitic stainless steel welded pipe will be the first choice
Since the heat exchanger tube constitutes the heat transfer surface of the heat exchanger, the size of the heat exchanger tube has a great influence on the heat transfer. When using small diameter tubes, the heat exchange area per unit volume of the heat exchanger is larger, the equipment is relatively compact, the metal consumption per unit heat transfer area is less, and the heat transfer coefficient is also higher. Although it is troublesome to manufacture, the use of austenitic stainless steel welded tubes as heat exchanger tubes can avoid the above problems. Because austenitic stainless steel welded tubes have good corrosion resistance and smooth surfaces, and the production process is mature, so austenitic Stainless steel welded tubes are the first choice for heat exchanger tubes. The materials that can be processed by Hangao Tech (SEKO Machinery) SZG-JM series welded pipe production line include: stainless steel, austenite, ferrite, titanium alloy and dual phase steel, which are very versatile and can be set and adjusted according to customer orders.
