SAW PIPE Production Process
Submerged arc welded (SAW) large line pipe derives its name from the stage in the production process wherein the welding arc is submerged in flux while the welding occurs. The flux protects the steel in the weld area from impurities found in the air when heated to welding temperatures. Double submerged arc welded (DSAW) large line pipe requires both inside and outside welds, which are accomplished in separate processes, hence the “double” prefix. DSAW encompasses both longitudinally welded SAW (LSAW) and helical (or spiral) welded SAW (HSAW).
Once formed, the cylinder is then welded both from the inside and the outside longitudinally along the length of the cylinder using the SAW process, with up to five welding wires, which in the end results in a welded pipe.
HSAW (or “spiralweld”) large line pipe is characterized as a steel pipe having a DSAW seam the entire length of the pipe in a spiral form. HSAW is produced using hot-rolled coil that is formed into a hollow cylinder by twisting the skelp as it is unrolled (in the same manner that the cardboard core in a roll of paper towel is formed) and then welded as the edges come together using an automated SAW process both inside the cylinder and outside the cylinder. The end product is a welded pipe.
Stages in the HSAW production process typically include: de-coiling and leveling; skelp end welding for continuous rolling; edge trimming and bevelling; forming and tack welding; cutting to length; skelp and repair welding; inside cleaning of pipe; internal and external SAW; further inside cleaning; weld seam removal at pipe ends; and beveling of pipe ends.
HSAW large line pipe production processes also comprise a number of quality control steps including, but not limited to, the following: skelp and edge ultrasonic testing; sampling and destructive testing; inspection of SAW; tack weld inspection; hydrostatic testing; ultrasonic testing; x-ray weld inspection/filmless radiography; final inspection; and generation of certificates. The complainant employs both the LSAW process and the HSAW process for its production of large line pipe.
ASTM A134 Electric-Fusion (Arc)-Welded straight seam or spiral seam welding, in nominal diameter of 16 inches (406.4mm) [NPS 16]and over, with wall thicknesses up to 3/4 in. (19.0 mm), inclusive.
ASTM A139 Electric-Fusion (Arc)-Welded straight-seam or helical-seam steel pipe. Pipes are manufactured in nominal diameters of 4 inches and larger with nominal (average) wall thickness of 1.0 in. [25.4 mm] and less.
AWWA C200-97: Steel Water Pipe-6 In. (150 mm) and Larger
BS 3601 Steel Pipe and Tubes for Pressure Proposes Carbon Steel: Ordinary Duties- Gr. 360,Gr. 430,
DIN 2460 Steel tubes for waterworks services DIN 2460
DIN 17120 Welded structural steel circular tubes for structural engineering purposes
DIN 17174 Welded circular steel tubes for low temperatures
DIN 17177 St. 37.8, St. 42.8
EN 10219-1, 2Cold formed welded structural hollow sections of non-alloy and fine grain steels. Part 1: Technical delivery requirements. Part 2: Dimensions
EN 10224 Steel pipess, joints and fittings for the conveyance of aqueous liquids including potable water
JIS G 3444 Carbon Steel Tubes for General Structural Purpose- STK 90,400,490,500,540
JIS G 3457 Arc Welded Carbon Steel Pipe- STPY 400
KS D 3566 Carbon Steel Tubes for General Structural Purpose- STK 90,400,490,500,540
KS D 3583 Arc Welded Carbon Steel Pipe- SPW 400
KS D 3566 STK 90,400,490,500,540 Carbon Steel Tubes for General Structural Purpose
3. Structural Pipe
API 2B Specification for the Fabrication of Structural Steel Pipe
API 2H Fabrication of Structure Steel Pipe
API 2W Fabrication of Structure Steel Pipe
ASTM A252-1,2, 3 Welded and Seamless Steel Pipe Piles, FOUNDATION PILES for soil consolidation, marine wharfs
AS1579 Arc-Welded Steel Pipes and Fittings for Water and Wastewater
AS 2159 Piling Design and Installation
AS 812 Bored Piles
JIS A5525 Steel Pipe Pile
KS F4602 Steel Pipes Piles
KS F4605 Steel Pipe Sheet Piles
External Coating
External Epoxy Coating
CSA Z245.20 Standard for External Fusion Bond Epoxy Coating for Steel Pipe
AWWA C210 Standard for Liquid-Epoxy Coating Systems for the Interior and Exterior of Steel Water Pipelines
AWWA C213 Standard for Fusion Bonded Epoxy Coating for the Interior and Exterior of Steel Water Pipelines.
NFA 49-710 Standard Specification for External FBE layered Coating
2.1.2 Polyethylene Coating
CAN/CSA Z245.21 External Polyethylene Coating for Pipe
DIN 30670 Polyethylene Sheathing of Steel Tubes and of Steel Shaped Fittings
NFA 49-710 External Three-Layer Polyethylene Based Coating, Application by Extrusion
AS/NZS 1518 External Extruded High-Density Polyethylene Coating System for Pipes
2.1.7 Bitumen Coating
DIN 30673 Bitumen coatings and linings for steel pipes, fittings and vessels.
2.1.8 Coal-Tar Enamel Coating
AWWA C-203 Coal-Tar Protective Coatings and Linings for Steel Water Pipelines-Enamel and Tape-Hot-Applied
AWWA C205 Cement Mortar Protective Lining and Coating for Steel Water Pipe - 4 inch (100 mm) and Larger- Shop Applied
2.2. Lining
2.2.1 Epoxy Lining
AWWA C210: Liquid-Epoxy Coating Systems for the Interior and Exterior of Steel Water Pipelines
NFA 49-709 Internal can be epoxy 80 microns
Steel Cement Lined piping2.2.2 Bitumen Lining
DIN 30673 Bitumen coatings and linings for steel pipes, fittings and vessels
UNI-ISO 5256/87 STANDARD-BITUMEN COATING
2.2.3 Cement Mortar Lining
AS/NZS 1516 Cement Mortar Lining of Pipelines In Situ
AWWA C203-02: Coal-Tar Protective Coatings & Linings for Steel Water Pipelines, Enamel & Tape, Hot-pap. (Incl. add. C203a-99)
AWWA C205-00: Cement-Mortar Protective Lining and Coating for Steel Water Pipe- 4 In. (100 mm) and Larger-Shop application
AWWA C602 Standard for Cement-Mortar Lining of Water Pipelines - 4 inch (100 mm) and Larger - In Place
AS1281 Mild
