Difference between ERW and SAW steel pipe

ERW is a electric-resistance welded steel pipe, Resistance welded steel pipe is divided into exchange of welded steel pipe and DC welded steel pipe in two forms.

AC welding in accordance with different frequencies are divided into low-frequency welding, IF welding, welding of ultra-IF and high-frequency welding. High-frequency welding is mainly used for the production of thin-walled steel pipe or wall thickness steel pipe, high frequency welding into contact welding and induction welding. DC welding is generally used for small-diameter steel pipe. So, in terms of comprehensive, high-frequency welded pipe included in the ERW pipe is a high-frequency welding process to produce ERW pipes. ERW Longitudinal advanced product performance in the field of oil and gas storage and transportation, quality leadership, more economical steel pipe.

SAW steel pipes is short of Submerged Arc Welding Steel Pipe, which it is a use of submerged arc soldering process to manufacture steel, the process produces a very high current density, the flux layer to prevent the rapid loss of heat, and concentrated in the welding region. Submerged arc weld of high quality, high production efficiency, arc and smoke a few characteristics of submerged arc welded pipe is widely used in pressure vessels, pipe manufacturing, beams, low pressure fluid, steel works. The main products of the SAW steel pipes LSAW Steel Pipe, Longitudinally Submerged Arc Welding Steel Pipe LSAW steel pipe, it is the use of submerged arc welding production of straight seam steel pipe.

Difference between erw and saw steel pipe

As ERW steel pipe and SAW steel pipe in the pipe during forming, welding and process is different, so that two kinds of steel pipe in the performance there are some differences.

(1) ERW steel pipe surface quality is superior to spiral submerged arc welded pipe, ERW steel pipe surface is smooth, smooth, beautiful, SAW steel pipe internal and external weld reinforcement.

(2) ERW steel pipe weld defect types is less than the saw steel pipe. Saw steel pipe with solvent deposited, more types of defects, in addition to volume defects, there are wire-line trap. ERW steel pipe weld defects only wire-line and straight welds, the inspection process easy to follow, and the defects in the maximum reflection at, once the lack of implicit, ultrasonic reflecting the strong, easy to detect.

(3) ERW steel pipe related to saw steel pipe in residual stress ratio is low. Since ERW pipe deformation in the deformation process more fully, coupled subsequent sizing flat oval, elliptical vertical changes and necking, making ERW pipe residual stress becomes smaller. Physical testing showed that the same specifications, the same material ERW pipe after incision along the axis, the axial and transverse incisions smaller displacement than the spiral submerged arc welded pipe.

(4) ERW Pipe overall performance of the same, when the pipe becomes defective, steel scrap judgment, allow welding. SAW steel pipe allowed, and pipe welding performance and overall performance is inconsistent, welding place prone to stress corrosion cracking. Experiments show that stress corrosion fatigue test ERW pipe spiral submerged arc welded pipe length than life.

Weled steel pipe specification, Standard and identification

Welded steel pipe (steel pipe manufactured with a weld) is a tubular product made out of flat plates, known as skelp, that are formed, bent and prepared for welding.