SAW Pipes
SAW pipes for reliable and strong construction.
DSAW double submerged arc welded steel pipe is high-strength large-diameter welded tubing designed for long-distance fluid transportation and heavy structural construction projects.
DSAW pipes on production line
Longitudinal and spiral seam steel pipes manufactured by double-sided submerged arc welding for oil, gas, water and structural applications.
DSAW pipes can be produced in very large diameters with tight control of both inside and outside dimensions. Spiral-welded executions feature a continuous helical seam and are available in single lengths up to 155 ft (47 m), making them suitable for long-distance transmission pipelines and heavy-wall structural service.
The process delivers deep weld penetration, low residual stress and excellent dimensional accuracy, ensuring long-term integrity under high internal pressure and external loading conditions.
Steel plates or coils are formed into cylindrical shapes. Edges are machined to create controlled V-grooves on both interior and exterior surfaces to ensure full penetration.
Internal and external seams are welded simultaneously using multi-wire submerged arc welding under flux. The arc burns beneath a layer of granular flux, preventing atmospheric contamination and supporting high current density.
The process achieves 100% wall-thickness penetration, producing a metallurgically sound, high-strength bond suitable for critical service conditions.
Online ultrasonic testing provides 100% coverage of longitudinal and spiral welds. Automatic alarms identify and mark any indication for immediate review.
Each pipe is subjected to hydrostatic pressure testing with radial sealing. Parameters are digitally recorded and traceable to the individual pipe.
Pipe ends are machined to precise bevel angles, squareness and wall alignment for field welding compatibility.
Our technical team supports projects from engineering through delivery, including material selection, internal/external coating, double-jointing and logistics coordination.
Integrated supply solutions are available for EPC contractors, utility operators and infrastructure developers worldwide.
Large-diameter DSAW pipes in service
| Product Name | Executive Standard | Dimension (mm) | Steel Code / Steel Grade |
|---|---|---|---|
| Casting | API 5CT | Ø48.3~273 x WT2.77~11.43 | J55, K55, N80, L80 |
| Tubing | API 5CT | Ø48.3~273 x WT2.77~11.43 | J55, K55, N80, L80, H40 |
| Product Name | Executive Standard | Dimension (mm) | Steel Code / Steel Grade |
|---|---|---|---|
| Line Pipes | API 5L | Ø60.3~273.1 x WT2.77~12.7 | A25, A, B, X42, X46, X52, X56, X60, X65, X70, X80 |
| Product Name | Executive Standard | Dimension (mm) | Steel Code / Steel Grade |
|---|---|---|---|
| Electric-Resistance-Welded Steel Pipes | ASTM A135 | Ø42.2~114.3 x WT2.11~2.63 | A |
| Electric-Resistance-Welded Carbon Steel and Carbon-Manganese Steel Boiler and Superheater Tubes | ASTM A178 | 42.2-114.3 x 2.11-2.63 | A, C, D |
| ERW and Hot-dip Galvanized Steel Pipes | ASTM A53 | Ø21.3~273 x WT2.11~12.7 | A, B |
| Pipes for Piling Usage | ASTM A252 | Ø219.1~508 x WT3.6~12.7 | Gr.2, Gr.3 |
| Tubes for General Structural Purpose | ASTM A500 | Ø21.3~273 x WT2.11~12.7 | Gr.2, Gr.3 |
| Square Pipes for General Structural Purpose | ASTM A500 | 25 x 25~160 x 160 x WT1.2~8.0 | Carbon Steel |
| Product Name | Executive Standard | Dimension (mm) | Steel Code / Steel Grade |
|---|---|---|---|
| Threaded Steel Pipes | DIN 2440 | Ø21~164 x WT2.65~4.85 | Carbon Steel |
| Product Name | Executive Standard | Dimension (mm) | Steel Code / Steel Grade |
|---|---|---|---|
| Screwed and Socketed Steel Tubes | BS 1387 | Ø21.4~113.9 x WT2~3.6 | Carbon Steel |
| Scaffolding Pipes | EN 39 | Ø48.3 x WT3.2~4 | Carbon Steel |
| Product Name | Executive Standard | Dimension (mm) | Steel Code / Steel Grade |
|---|---|---|---|
| Carbon Steel Tubes for General Structure Purpose | JIS G3444 | Ø21.7~216.3 x WT2.0~6.0 | Carbon Steel |
| Carbon Steel Tubes for Machine Structure Purpose | JIS G3445 | Ø15~76 x WT0.7~3.0 | STKM11A, STKM13A |
| Carbon Steel Pipes for Ordinary Piping | JIS G3452 | Ø21.9~216.3 x WT2.8~5.8 | Carbon Steel |
| Carbon Steel Pipes for Pressure Service | JIS G3454 | Ø21.7~216.3 x WT2.8~7.1 | Carbon Steel |
| Carbon Steel Rigid Steel Conduits | JIS G8305 | Ø21~113.4 x WT1.2~3.5 | G16~G104, C19~C75, E19~E75 |
| Carbon Steel Rectangular Pipes for General Structure | JIS G3466 | 16 x 16~150 x 150 x WT0.7~6 | Carbon Steel |
Pipeline coating is the most consistent and successful solution for protecting ERW pipes from corrosion, from moisture, other harmful chemicals.
Anti-corrosion steel pipe is processed through the preservation process, which can effectively prevent or slow down the process in the transport and use of chemical or electrochemical corrosion reaction of steel pipe.
Therefore pipe anti-corrosion layer is an important barrier to prevent soil erosion. A well-known foreign scholar put forward” 3PE france protective layer”, so far, anti-corrosion methods is widely used.
Coated pipes offer high resistance to corrosion on pipes and provide many benefits such as:
The basic principles of urban gas pipeline coating selection:
Ceramic lined pipe is made through self-propagating high-temperature synthesis (SHS) technique.
Cast basalt lined steel pipe is composed by lined with cast basalt pipe, outside steel pipe and cement mortar filling between the two layers.
Ceramic tile lined pipes have very uniform coating of specially formulated ceramic material that is affixed to the inner of the pipe.
The material of the rare earth alloy wear-resistant pipe is ZG40CrMnMoNiSiRe, which is also the grade of rare earth alloy steel.
Tubes Erosion Shields are used to protect boiler tubing from the highly erosive effects of high temperatures and pressures thereby greatly extending tube life.
The ASTM A213 T91 seamless tubes are primarily used for boiler, superheater, and heat-exchanger.
When you partner with Sunny Steel, you can stop worrying about meeting deadlines thanks to our responsive and timely service. You'll also say goodbye to unnecessary shopping around. Instead, you'll get white glove service from an expert who understands your needs and can get you the materials you need quickly.
