LSAW (Longitudinal double submerge arc welding) is a type of SAW pipe made of steel plates that were hot rolled by JCOE or UOE forming technology. JCOE technology represents the shaping and forming processes involved during manufacturing as well as the inner and outer welding and cold expansion carried out after welding.

Standard: 

ASTM 53

API Spec 5L

ASTM A252-89, EN10217, EN10219

Steel grades:

API 5L: GR A, GR B, X42, X46, X56, X60, X65, X70

ASTM A252 GR 1, GR 2, GR 3

ASTM A53: GR A, GR B, GR C, GR D

BS 4360: Grade 43, Grade 50

EN: S275, S275JR, S355JRH, S355J2H

Size range by usage

ASTM A252 Piling Pipe application in buildings and retaining walls

Application of LSAW Steel Pipe

Used for oil/gas/water

Transmission

Engineering

Offshore projects.

Manufacturing Process of LSAW steel pipe
Longitudinally Submerged Arc Welded Process Flow
LSAW (Longitudinally Submerged Arc Welded Steel pipes) in leaflets plate as raw material, the steel plate in the mold or molding machine pressure (volume) into using double-sided submerged arc welding and flaring from production.

The LSAW process of welded tube includes UOE and JCOE
UOE LSAW pipe forming process:
The three main forming processes of UOE LSAW steel pipe forming process include: steel plate pre-bending, U forming and O forming. Each process adopts a dedicated forming press to complete the three processes of pre-bending the edge of the steel plate, U forming and O forming in sequence to deform the steel plate into a circular tube.

Tests of LSAW steel pipe
Chemical Component Analysis
Mechanical Properties – Elongation, Yield Strength, Ultimate Tensile Strength
Technical Properties – DWT Test, Impact Test, Blow Test, Flattening Test
X-ray Test
Exterior Size Inspection
Hydrostatic Test
UT Test

Transportation of LSAW steel pipe
When transporting, loading and unloading erw welded pipes, special hoisting and transportation tools should be used to avoid scratching the surface.

Forming: After several steps of stamping on the JC0 forming machine, first half of the steel plate is pressed into a "J" shape, then the other half of the steel plate is pressed into a "J" to form a "C" shape, and finally pressurized from the middle to form An open "0"-shaped tube blank is formed.

LSAW Pipes with JCOE forming mode:




Production equipment of LSAW steel pipe
Plate edge milling machine
The milling machine mills the two sides of the plate to exacting standards in order to meet width, edging and groove shape specifications.

Edge crimping machine
The crimping machine crimps the edges of the plate to form the required curvature.

Tack welding machine
The two edges of the open seam pipe are brought together by the tack welding machine. then welded by the tack welder using a metal active - gas arc welding("MAG" )process.

Forming machine
Utilizes the "JCO" process to bend and form the crimped steel plate into a steel pipe.

Interior welding machine
The interior longitudinal seam of the pipe is welded from the inside by fixing 4 welding heads while moving pipe and using submerged-arc welding process.

End facing machine
The machine levels the pipe end with rotating cutter heads to ensure that required groove and edge specifications are met.

Hydrostatic tester
Using end face sealing technology eliminates blind zones during hydrostatic testing. The tester is also equipped with automatic recording and storing functions.

Expanding machine
The pipe is subjected to full-length expansion to increase the precision of the pipe dimensions and to improve the internal stress distribution.