The difference between double-submerged arc welding(dsaw) and high-frequency difference(HFW) is mainly manifested in the appearance of the weld appearance, Double submerged arc welding steel pipe in appearance is with a slight indentation strip, mainly in the steel interior. Straight seam submerged arc weld pipe is higher than the base material for the neat 1-3mm weld. In appearance frequency steel tube smooth, non-oxide adhesion. In the weld, high-frequency straight seam steel pipe weld high measure to squeeze flow resistance, the jagged serrate irregular weld, this weld is "scratch" before they go out, leaving a flat weld removal of trace.

In addition, two-sided submerged arc welding and high-frequency difference are also reflected in the production process, the use of different raw materials, different molding processes, the welding process being different from different production units, and the production of different scopes. Sided submerged arc welding straight seam steel production process only with JCOE molding process complex, forming efficiency relative to the low-frequency welded pipe, so the manufacturing cost is higher than the high-frequency straight seam welded steel pipe. The high-frequency straight seam welded steel pipe (ERW) production process is simple, with a single specification. The double-sided submerged arc straight seam steel pipe forming process is JCOE cold forming, features that make the steel at 50mm gradually forming, J, C, O, E represents the image of straight seam steel submerged arc forming process. Frequency straight seam steel pipe forming process for the multi-pass rolls, squeeze both ends of the strip, and finally justified the strip cold molding process, the molding process is characterized by uninterrupted, continuous welding. The submerged arc welding process is characterized by using steel wire electric effect and melting together, as filler welding. The frequency straight seam steel pipe welding process is characterized by the use of high-frequency current skin effect rapid warming strip ends in a short time under the action of external forces strip from melting together.

Frequency straight pipe production unit for the same lines of uninterrupted production line efficiency, and submerged arc welding straight seam steel pipe has up to 15 intermittent production processes complete unit. Frequency straight seam steel pipe production specifications fewer production thinner.

Cangzhou Shenlong Pipe Manufacturing Co., Ltd. cooperates with Baosteel and Baogang to produce large-caliber seamless steel pipe, straight-seam welded pipe, spiral steel pipe, and pipe fittings. The products comply with API, ASTM, DIN, BS, and JIS standards, and can accept SGS, BV, and other inspections. The products are used in oil, natural gas, bridge, water conservancy, and other large-scale projects, which are worthy of trust.