What is the LSAW steel pipe?
LSAW (Longitudinal submerged arc welded steel pipe) steel pipe is made of a small leaf plate as raw material, and the steel plate is produced by double-sided submerged arc welding and flaring under the pressure (volume) of the mold or forming machine. The finished product has a wide range of specifications, good weld toughness, ductility, uniformity, and compactness, and has the advantages of large diameter, wall thickness, high-pressure resistance, and low-temperature corrosion resistance. High-toughness, high-quality long-distance oil, and gas pipelines are mostly large-diameter thick-walled LSAW.
Application of LSAW steel pipes
LSAW steel pipes are used in onshore & offshore oil and gas pipelines, where require careful services, high performance, and tight tolerances. LSAW pipelines are also used to transport flammable and non-flammable liquids and used as structural components in construction projects.
Specification of JS LSAW steel pipes
The LSAW pipe (Longitudinal Submerged Arc Welded Pipe) is made by JCOE and has a straight weld with an outer diameter of usually 323mm to 1420mm. When the outer diameter is greater than 914.4mm, two straight welds are allowed. LSAW pipes are used to transport low-pressure liquid media or high-pressure oil or natural gas, and can also be widely used in structural supports or foundations.
The advantage of the LSAW type is that they can produce thicker pipe wall thickness, up to 120mm.
Specification:
OD: 219mm-1820mm
Wall thickness: 5.0mm-50mm
Length of each pipe: 6m-18m
Ends treatment: square head (straight cut, saw cut, and torch cut). Or chamfer for welding, chamfering.
Surface treatment: oiled, hot-dip galvanized, electro-galvanized, black, nude, varnish coating/anti-rust oil, protective coating
Packing: Both ends are equipped with plastic plugs, the largest hexagonal bundle is 2,000kg, with several steel bands, each bundle has two labels, wrapped in waterproof paper, PVC sleeve, sackcloth, with several steel bands, plastic cap.
General Test
1) chemical composition analysis
2) mechanical properties: ultimate tensile strength, yield
Strength, elongation
3) technical performance: flatness test, bending test, blow molding test, impact test
4) appearance and size inspection
5) hydrostatic pressure test
6) X-ray test
The production process of large diameter LSAW steel pipe
Rolling machine→Uncoiler→Unwinder→Retripper leveling machine→Vertical roll centering→Shear butt welding→Strip position control (double-head vertical roller)→Disc shearing→Strip position control (Double-head vertical roller )→ Edge Milling Machine (Fine Milling X Groove)→ Double End Roller→ Strip Surface Cleaning of Strips→ Double End Roller→ Conveyor→ Strip Feeding and Strip Position Control→ Molding Machine→ Inner Welding→ Outside Welding → steel pipe righting device → plasma cutting → straight seam steel pipe outlet
Main features of LSAW steel pipe:
1) The steel pipe has a longitudinal weld, the inner and outer welds are all-welded by submerged arc welding.
2) After the overall mechanical expansion treatment, the internal stress of the steel pipe is small and evenly distributed, which can effectively prevent stress corrosion cracking, has high dimensional accuracy, and is convenient for on-site welding construction.
3) Pre-welding and finishing welding process is adopted, the welding process is stable, and the welding seam quality is high.
4) Welding seam is easy to realize non-destructive flaw detection in the production process and non-destructive flaw detection in the field during use.
5) The range of product specifications is large, which can produce steel pipes with small diameter and large wall thickness as well as large diameter and large wall thickness.
