Welded Pipe MS Black Pipe Manufacturer
We are ERW steel pipe direct manufacturer,authorized by API 5L & API 5CT
For welded type pipe, also have LSAW & SSAW PIPE
Difference ERW/ LSAW /SSAW
Feature | ERW Pipe | LSAW Pipe | SSAW Pipe |
Key Differentiator | Smooth, barely visible seam. No filler metal. High-frequency resistance weld. | Single, straight, prominent seam. Made from heavy plates, not coil. | Distinct, continuous spiral seam. Most flexible in diameter from a given coil width. |
Primary Raw Material | Hot/Rolled Cold-rolled steel coil. | Single steel plates (medium to heavy thickness). | Hot-rolled steel coil. |
Size Range (Typical) | Small to medium diameter. OD: 1/2" to 24". Thinner walls. | Large diameter, heavy wall. OD: 20" to 60" and above. The choice for heavy-wall, large OD. | Large to very large diameter. OD: 8" to 120" . Excellent for large OD with relatively thinner walls. |
Weld & Mechanical Properties | Weld seam is heat-treated, making it comparable to the base metal. Good for uniform pressure. Not suitable for severe cyclic loading. | Superior weld quality and strength. Excellent impact toughness. Lowest residual stress. The premium choice for high-pressure, critical applications. | Good overall strength. The long spiral weld and higher residual stress make it less ideal for high-pressure dynamic services or low-temperature environments. |
Main Applications | Low/medium-pressure fluid conveyance (water, gas), structural purposes (scaffolding, furniture, mechanical tubes). | High-pressure oil & gas transmission pipelines, offshore lines, major plant piping, heavy load-bearing structures. | Low/medium-pressure fluid transport (water, sewage), piling, foundation supports, wind turbine towers, structural columns. |
Cost & Economics | Most cost-effective. High production efficiency, continuous process. | Highest cost. Due to plate cost, complex forming, and stringent testing. A premium product. | Competitive for large diameters. Efficient material use (coil), lower tooling cost for varying diameters. |
Common Int'l Standards | API 5L, ASTM A53, ASTM A500, EN 10219, JIS G3444 | API 5L (PSL2 common), ASTM A671, DNVGL-ST-F101, ISO 3183 | API 5L, ASTM A139, EN 10217, SY/T 5037 |
Key Selling Points | "Economical, smooth, and precise. Perfect for structural applications and standard fluid transport ." | "Maximum safety and performance. For critical, high-pressure environments. The benchmark in pipeline integrity ." | "Cost-efficient solution for large-diameter requirements. |
Recommendations:
For general purpose, structural, or low-cost fluid transport:RecommendERW.
For critical, high-pressure hydrocarbon pipelines or premium applications:SpecifyLSAW. It is the undisputed choice for integrity and safety in demanding service.
For large-diameter water lines, foundation piling, or structural columns where cost is a major factor:OfferSSAW.
ERW have welded seam inside of pipe
LSAW have welded seam both pipe inside and outside
SSAW shape is helical structure
