high-frequency straight seam welded pipe (ERW), spiral submerged arc welded pipe (SSAW), and LSAW steel pipe (LSAW), These pipelines are often used in natural gas projects, oil projects, or some other industrial projects, what is the difference between them, how we should choose, we will describe in detail.

The following table shows the characteristics of several steel processes and quality performance comparisons:

Straight seam high frequency welded pipe (ERW steel pipe) by welding and induction welding is divided into different exposure to welding in two forms, using broadband hot-rolled coils as raw materials, pre-curved, continuous molding, welding, heat treatment, sizing, straightening, cutting and other processes, and spiral welded pipe weld compared to the short, high dimensional accuracy, uniform thickness, surface quality, the advantages of higher pressure, but the drawback is that only produce small-caliber thin-walled tube, easy to produce weldsgray leaf spot, not fusion, groove-shaped corrosion defects. At present more extensive application areas of the city gas, crude oil transportation, and so on.

Spiral submerged arc welded pipe (SSAW steel pipe) is the strip volume control when the forward direction and forming a molding pipe centerline angle (adjustable), side molding edge welding, the weld into a spiral, the advantage of the same specifications of the strip can production of a variety of diameters of pipe, meet a wider range of raw materials, welds can avoid the main stress, the force is better, the disadvantage is poor geometry, the weld seam length compared to the straight pipe length, easy to produce cracks, pores, slag, welding, and other welding defects side, welding stress was tensile stress state. General long-distance gas pipeline design specification spiral submerged arc welded pipe can only be used for Class 3, and Class 4 areas.

Foreign raw materials will be changed to improve this process steel, so that separate forming and welding, the welding and lean pre-, post-weld cold-expanding, then the quality of welding close to the UOE pipe, currently there is no such process, is the spiralFactory directions for improvement. "Natural Gas" is still used by the traditional spiral process of production, but the tube side of the expander. United States, Japan, and Germany in general negative SSAW, that trunk should not use SSAW; Canada and Italy, some use SSAW, Russia, a small amount of use SSAW, and have developed a very strict additional condition, due to historical reasons, most still use the main trunk domestic SSAW. LSAW pipe (LSAW) is a single plate as raw material, steel in the mold or molding machine pressure (volume) into the tube, using a double-sided submerged arc welding method and Expanding from the produce.

In the construction of high-strength, high toughness, high-quality long-distance gas pipeline, most of the required large diameter thick wall steel pipe LSAW pipe. According to API standards, in large oil and gas pipelines, when through the alpine zone, sea, cities and other densely populated areas Class 1, Class 2 areas, LSAW pipe is the only designated suitable tube. By forming different ways can be divided into:

• UOE welded pipe: sheet steel at the edge of the pre-bend, the U shape, O shape, welded inside and outside welding, mechanical cold Expanding processes;

• JCOE pipe: ie "JCOE" pre-welding, forming, welding, and other processes by the cold expander;

• HME pipe: the mandrel rolling basis over the "CCO" forming, welding, and other processes by the cold expander.

The wide range of product specifications, weld toughness, ductility, good uniformity, and density, with a large diameter, wall thickness, high pressure, low-temperature corrosion resistance, and other advantages.

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.