Spiral welded pipe(SSAW pipe, also called HSAW pipe). The pipe is formed by spiral submerged arc welding technology. Spiral welded pipes are formed using narrower plates or hot rolled coils, which lowers their production costs significantly. The welding line is shaped like a helix. The spiral welding process permits the production of large-diameter pipes suitable for transporting large volumes of oil and gas. Some SSAW pipes were historically limited to low-pressure applications.
High-frequency welded pipes are generally straight-slit, but straight-slit welded steel pipes are not necessarily high-frequency welded. The high-frequency straight-slit electric resistance welded steel pipe is formed by the skin effect and the proximity effect of the high-frequency current after the hot-rolled coil plate is formed by the molding machine, and the edge of the tube blank is heated and melted, and pressure welding is performed under the action of the pressing roller to realize the production. The high-frequency resistance welded steel pipe is different from the ordinary welded pipe welding process. The weld is made of the base material of the steel strip body, and the mechanical strength is better than that of the general welded pipe. The surface is smooth, high precision, low cost, and has low weld seam height, which is beneficial to the coating of 3PE anti-corrosion coating.
Longitudinal submerged arc welded is produced by using a single medium and thick plate as the raw material, pressing (rolling) the steel plate in a mold or forming machine into a tube blank, using double-sided submerged arc welding, and expanding the diameter. The steel plate feed amount can be automatically adjusted according to different steel grades, wall thicknesses, and plate widths. At the same time, the deformation compensation function effectively avoids the adverse effects of mold deformation on the forming and ensures the flatness of the full length of the steel plate during the pressing process. The feeding step is uniform during forming, ensuring the roundness of the tube blank and the flatness of the welding edge. The finished product has a wide range of specifications, and the weld has good toughness, plasticity, uniformity, and compactness. It has the advantages of large pipe diameter, pipe wall thickness, high-pressure resistance, low-temperature resistance, and strong corrosion resistance.
The hot expanded seamless steel pipe is relatively low density but the contraction of the strong seamless steel pipe can be referred to as thermal expansion. The roughing finishing process for expanding the diameter of a pipe by a cross-rolling method or a drawing method. Steel pipe thickening in a short period can produce non-standard and special types of seamless tubes with low-cost and high production efficiency, the current international developments in the field of tube rolling.
Cold Drawn Seamless Steel Pipe as implied is made by cold drawing a larger mother seamless pipe, which is generally manufactured through an HFS process. In the Cold Drawn Seamless process, the mother pipe is pulled through a die & plugin cold without any heating. Because of the tool on the outside and inside the surface and tolerances are better in Cold Drawn Seamless. While this is an additional process over HFS, it is necessary to get smaller size pipes that otherwise cannot be manufactured in HFS. Some applications which require close tolerances and smooth surfaces also specify the requirements to be necessarily Cold Drawn Seamless. Cold Drawn Seamless pipes & tubes are extensively used in Heat-Exchanger, Bearing & Automotive sectors. Cold drawn seamless steel pipe is used for the mechanical structure, hydraulic equipment, which has precision size, good surface finish. It can greatly reduce mechanical processing hours and improve material utilization, and improve the quality of products. High-quality cold-drawn seamless steel pipes are mainly using the 10# 20#. In addition, to ensure chemical composition and mechanical properties, it will check by the Hydrostatic test, crimping, flared, and Squashed test. Cold Drawn Seamless (CDS) as implied is made by cold drawing a larger mother seamless pipe, which is generally manufactured through an HFS process. In the CDS process, the mother pipe is pulled through a die & plugin cold without any heating. Because of the tool on the outside and inside the surface and tolerances are better in CDS. While this is an additional process over HFS, it is necessary to get smaller size pipes that otherwise cannot be manufactured in HFS. Some applications which require close tolerances and smooth surfaces also specify the requirements to be necessarily CDS. CDS pipes & tubes are extensively used in Heat-Exchanger, Bearing & Automotive sectors.
