LSAW Pipe
Longitudinal submerged-arc-welded (LSAW) pipe — for large-diameter, high-pressure lines — in carbon and low-alloy grades to API 5L / ASTM.
Technical specification
| Parameter | Specification |
|---|---|
| Product | Longitudinal submerged-arc-welded (LSAW / SAWL) pipe — heavy plate formed to a cylinder with a single straight seam |
| Manufacturing route | UOE or JCOE plate forming + longitudinal SAW (inside & outside), cold-expanded where specified. Forming route and expansion are separate descriptors. |
| Dimensional standard | Ordered by actual OD × wall thickness; API 5L / ASME B36.10M reference |
| Size range | 16" – 60" OD (large-diameter) — grade / wall-specific; smaller sizes via ERW or seamless |
| Wall / grade | Custom OD × plate thickness; not a continuous universal schedule range |
| Material specifications | API 5L SAWL (PSL1 / PSL2); ASTM A671 (EFW pressure pipe); ASTM A252 (piling). A672 EFW available where specified. |
| Sour service | API 5L sour annex + NACE MR0175 / ISO 15156-2 where qualified — not implied by PSL2 alone |
| Documentation | EN 10204 3.1 / 3.2, plate & weld traceability, weld map |
How it is made
LSAW pipe is made from heavy plate formed into a cylinder by the UOE press route (U-ing, O-ing, then expansion) or the JCOE press-bending route, welded along a single straight seam by submerged-arc welding from inside and outside, and cold-expanded to final diameter and roundness. UOE and JCOE are forming routes and cold expansion is a manufacturing step — neither is an inspection, and neither is a universal consequence of “LSAW”; the fixed diameters a mill can form are tooling-dependent. The seam is examined by radiography and / or ultrasonics to the extent the specification, grade / PSL, thickness and purchaser options require — not automatically 100 % UT + RT on everything — with end / dead-zone provisions, and impact / DWTT and hydrostatic testing where required. Longitudinal SAW overlaps EFW / SAW terminology; the spiral-seam alternative is SSAW. Schedule or PSL does not by itself define a pressure rating; the design code, wall after tolerance and joint factor govern.
Grades & materials
LSAW is a carbon / low-alloy line-pipe product. The specifications below are the verified scope; availability by grade, PSL, OD and wall is confirmed on quotation. Seamless, stainless, duplex and nickel pipe are covered on their own pages, not here.
| Product | Grades | Standard | Service |
|---|---|---|---|
| Line pipe (SAWL) | API 5L B, X42, X46, X52, X56, X60, X65, X70, X80 (PSL1 / PSL2) | API 5L | Oil & gas transmission |
| Sour line pipe | API 5L sour grades (e.g. X52–X65) + ISO 15156-2 qualification | API 5L Annex + ISO 15156-2 | Sour service (qualified per project) |
| EFW pressure pipe | A671 CC65, CC70 (class controls treatment & testing) | ASTM A671 | Atmospheric / lower-temp pressure |
| Piling (structural) | A252 Gr.1, Gr.2, Gr.3 | ASTM A252 | Pipe piles — not pressure pipe |
Chemical composition (representative)
| Grade | Spec | C max | Mn max | P max | S max | Microalloy |
|---|---|---|---|---|---|---|
| Gr.B | API 5L PSL2 | 0.22 | 1.20 | 0.025 | 0.015 | Nb / V / Ti as agreed |
| X52 | API 5L PSL2 | 0.22 | 1.40 | 0.025 | 0.015 | Nb + V + Ti ≤ 0.15 |
| X60 | API 5L PSL2 | 0.12 | 1.60 | 0.025 | 0.015 | Nb + V + Ti ≤ 0.15 |
| X65 | API 5L PSL2 | 0.12 | 1.60 | 0.025 | 0.015 | Nb + V + Ti ≤ 0.15 |
| X70 | API 5L PSL2 | 0.12 | 1.70 | 0.025 | 0.015 | Nb + V + Ti ≤ 0.15 |
| X80 | API 5L PSL2 | 0.12 | 1.85 | 0.025 | 0.015 | Nb + V + Ti ≤ 0.15 |
| A671 CC70 | A671 / A516-70 | 0.30 | 0.85–1.20 (range) | 0.030 | 0.030 | Si 0.15–0.40; plate A516-70 |
| A252 Gr.2 / 3 | A252 | — | — | 0.05 | — | Piling — mechanically governed |
Standards & specifications
Product & dimensional
- API 5L PSL1 / PSL2 SAWL line pipe (ordered by OD × wall)
- ASTM A671 EFW pressure pipe (grade + class)
- ASTM A252 pipe piles (Gr.1 / 2 / 3, structural)
- Reference dimensions: ASME B36.10M; actual OD × plate thickness for line pipe
Testing & service
- Seam RT and / or UT per specification, grade / PSL, thickness & order — not a universal 100 % UT + RT
- Impact / DWTT and hydrostatic testing where required; end / dead-zone provisions
- Sour: API 5L sour annex + ISO 15156-2 / MR0175, with HIC / SSC where applicable — not implied by PSL2
- Schedule / PSL is not a pressure rating; design code, wall after tolerance & joint factor govern
Mechanical properties (representative grades)
Representative grades — full MTC values on request. API values are specified minimum yield (SMYS) and tensile (SMTS); PSL2 also sets maximum yield / tensile and a yield-to-tensile ratio limit. Transverse weld tensile, guided-bend and (where required) DWTT / Charpy also apply. Piling (A252) values are for structural design, not pressure service.
| Grade | Spec / basis | Tensile min (MPa) | Yield min (MPa) | Elong min (%) |
|---|---|---|---|---|
| Gr.B | API 5L line | 415 | 245 | — |
| X42 | API 5L line | 414 | 290 | — |
| X46 | API 5L line | 435 | 320 | — |
| X52 | API 5L line | 460 | 360 | — |
| X56 | API 5L line | 490 | 390 | — |
| X60 | API 5L line | 520 | 415 | — |
| X65 | API 5L line | 535 | 450 | — |
| X70 | API 5L line | 570 | 485 | — |
| X80 | API 5L line | 625 | 555 | — |
| A671 CC65 | A516-65 plate | 450–585 | 240 | 23 |
| A671 CC70 | A516-70 plate | 485–620 | 260 | 21 |
| A252 Gr.1 | Piling | 345 | 207 | — |
| A252 Gr.2 | Piling | 414 | 241 | — |
| A252 Gr.3 | Piling | 455 | 310 | — |
Testing, inspection & documentation
| Test / document | Detail |
|---|---|
| Chemical / PMI | Parent-plate and, where specified, weld-metal chemistry with CE; PMI does not replace full chemistry |
| Tensile (base & weld) | Base-metal and transverse weld tensile (ASTM A370 / API 5L) |
| Guided-bend / flattening | Weld ductility per the product standard |
| Impact / DWTT | Charpy (parent / weld / HAZ) and, where required, DWTT at the specified temperature and criteria |
| Seam NDE | Radiography and / or ultrasonics per grade / PSL / thickness & order, including end / dead-zone provisions; RT and UT are not automatically interchangeable |
| Lamination / hydrostatic | Plate / body lamination checks where required; hydrotest per the product standard (not one pressure for every size) |
| Traceability | Plate-to-pipe heat traceability and weld map where required |
| Certification | EN 10204 3.1 as standard; 3.2 validated by an independent authorised party |
Applications & industries served
Dimensions, weights & coatings
LSAW is ordered by actual OD × wall. Theoretical plain-end mass is kg/m = π × t × (D − t) × ρ × 10⁻⁶ (carbon-steel basis ρ = 7850 kg/m³); lb/ft ≈ kg/m × 0.672; nominal ID = D − 2t. Figures exclude weld reinforcement, coating, lining and concrete weight coating. A published OD range is not proof every wall / grade is available throughout it — availability is confirmed on RFQ.
Large-diameter theoretical mass (kg/m, carbon-steel basis)
| OD | OD (mm) | 7.9 mm | 9.5 mm | 12.7 mm | 15.9 mm | 19.1 mm |
|---|---|---|---|---|---|---|
| 16" | 406.4 | 78 | 93 | 123 | 153 | 182 |
| 18" | 457.0 | 87 | 105 | 139 | 173 | 206 |
| 20" | 508.0 | 97 | 117 | 155 | 193 | 230 |
| 24" | 610.0 | 117 | 141 | 187 | 233 | 278 |
| 30" | 762.0 | 147 | 176 | 235 | 293 | 350 |
| 36" | 914.0 | 177 | 212 | 282 | 352 | 422 |
| 42" | 1067.0 | 206 | 248 | 330 | 412 | 494 |
| 48" | 1219.0 | 236 | 283 | 378 | 472 | 565 |
| 56" | 1422.0 | 276 | 331 | 441 | 551 | 661 |
| 60" | 1524.0 | 295 | 355 | 473 | 591 | 709 |
External / internal coatings
| System | Governing standard | Use |
|---|---|---|
| 3LPE (3-layer polyethylene) | DIN 30670 / ISO 21809-1 | External, buried |
| 3LPP (3-layer polypropylene) | ISO 21809-1 | External, higher temperature |
| FBE (fusion-bonded epoxy) | ISO 21809-2 / API RP 5L7 | External / internal |
| Internal flow lining (epoxy) | API RP 5L2 | Flow efficiency / corrosion |
| Concrete weight coating | ISO 21809-5 | Subsea negative buoyancy |
Provide with your enquiry
- Specification / edition, grade and PSL / class, delivery condition.
- Actual OD and wall thickness, length and quantity.
- Coating / lining system, ends and examination scope.
And the commercial detail
- Service & design conditions (sour / offshore where relevant).
- Required tests, certification (3.1 / 3.2) and source restrictions.
- Delivery location and any BOQ.
Frequently asked questions
What is LSAW pipe?
LSAW (longitudinal submerged-arc welded, also called SAWL) pipe is made from heavy plate formed into a cylinder by UOE or JCOE, welded along a single straight seam inside and outside, and cold-expanded to final size. It is used mainly for large-diameter, higher-pressure line pipe. The forming route and expansion are separate descriptors, and it is ordered by actual OD × wall and grade.
Is LSAW better than SSAW because of the straight seam?
Not as a universal rule. Seam direction (longitudinal vs spiral) alone does not make one better — selection depends on the project code, the qualified manufacturing route, dimensions, toughness, fatigue and inspection requirements. Both can be fully acceptable when qualified for the service. UOE fixed diameters are also mill- and tooling-dependent, not a fixed universal set.
Does “X52–X65 NACE” mean the pipe is sour-service ready?
No. “NACE” is not a grade, and a yield-strength range is not a sour-service boundary. Sour qualification (to ISO 15156-2 / MR0175) depends on the H&sub2;S partial pressure, pH, temperature and the material’s condition, plus the applicable annex requirements and HIC / SSC testing — HIC testing by itself does not establish complete sour qualification. The exact grade, condition and environment are confirmed per project.
Which examinations are performed on the seam?
It depends on the specification, grade / PSL, thickness and purchaser options — it is not automatically “100 % UT + RT” on everything. The seam NDE method, coverage, location (including end / dead zones) and acceptance are stated per order, along with any impact / DWTT and hydrostatic testing where required. Cold expansion is a manufacturing step, not an examination.
Is coating just “API 5L + DIN 30670”?
No — each coating is its own specification and system. DIN 30670 covers extruded polyethylene (3LPE); 3-layer polypropylene (3LPP) and fusion-bonded epoxy (FBE, e.g. ISO 21809-2) have their own specifications, thicknesses and temperature limits, and internal lining is separate again. External corrosion coating, concrete weight coating and internal flow lining are distinct and specified individually.
Can you supply A671 pressure pipe and A252 piling in LSAW?
Yes, but as their own products. A671 is EFW pressure pipe for atmospheric / lower-temperature service, supplied by grade and class (the class controls heat treatment and testing), and it is not unrestricted riser approval. A252 piling is structural and supplied by its actual grade (Grade 1 / 2 / 3), not the bare spec number, with no automatic pressure-service substitution.
What information is needed for a quotation?
Provide the specification and edition, grade and PSL / class, delivery condition, OD and wall thickness, length and quantity, coating / lining system, service and design conditions (including any sour / offshore requirements), examination scope, ends and documentation. Availability by grade, OD and wall is confirmed with the quotation.
Request a quote
Send your requirement to Sagiant Piping Industries and our team responds with grade, material selection, availability and pricing for lsaw pipe. Attach a BOQ, line list or drawing for a faster, more accurate quotation.
- Fast RFQ response with grade & material-selection support
- EN 10204 3.1 / 3.2 certification, PMI & third-party inspection
- BOQ & line-list project supply — India & export
Mechanical & chemical values shown are ASTM/ASME specification figures; certified heat-specific values appear on the MTC. Availability is confirmed with the quotation.
