LSAW (Longitudinal Submerged Arc Welded)
/glossary/lsawPlate-formed pipe with a straight longitudinal submerged-arc weld seam.
LSAW is plate-formed pipe with one straight submerged-arc seam, used when a Kanpur-origin water-main or hydrocarbon package names that route. The product page lists 16 to 48 inch (406 to 1219 mm) as the usual LSAW OD band. A Unnao or Kanpur Dehat trunk that the consultant called HSAW stays on coil. Indent offers are raised from the Bartan Bazar desk, ex-warehouse Kanpur. Budget GST at 18% extra on the tube line; the tax invoice applies the rate in force.
In detail
Longitudinal Submerged Arc Welded (LSAW) pipe is made by forming steel plate into a cylinder and submerged-arc welding the longitudinal seam. Forming is commonly JCOE or UOE. The straight seam does not by itself approve a pressure, fluid, or project duty. Grade, wall, examination, coating, and mill qualification come from the purchased specification. Feasible OD and wall remain mill- and procedure-specific.
What LSAW is, and what it is not
LSAW is a manufacturing route. Steel plate is edge-prepared, formed into a cylinder, then joined by a longitudinal submerged-arc weld. The site comparison page names JCOE and UOE as the common plate-forming sequences, with a double-seam arrangement on some heavier walls.
It is not HSAW. HSAW starts from hot-rolled coil and welds a helical seam. It is not ERW. ERW is a high-frequency weld on a strip-formed tube in the IS 1239 size range. It is not seamless. A missing visible bead does not make plate pipe into a pierced billet.
It is not a pressure class. The LSAW versus HSAW page states that pressure suitability follows the design code, actual wall, grade, joint factor, corrosion allowance, and project requirements. The straight seam is an inspection geometry, not a licence to raise design pressure.
ASTM A672/A672M-19 (reapproved 2025) is a related electric-fusion-welded plate-pipe specification. Scope 1.1 covers pipe electric-fusion-welded with filler metal added, fabricated from pressure-vessel quality plate. Scope 1.2 nominally covers 16 in (400 mm) OD or larger with wall up to 3 in (75 mm). A mill may fill that spec with a longitudinal SAW seam. Write A672 only when the drawing names it.
Who should specify LSAW, and who should stay on HSAW or ERW
Specify LSAW when the approved project specification and the mill-qualification list name a longitudinal SAW route. Cross-country oil and gas owners often do that. Some heavy-wall water or piling packages do the same.
Stay on HSAW when a Jal Nigam or JJM water BOQ names spiral SAW to IS 3589. The comparison page notes that PWD / Jal Nigam water BOQs commonly accept HSAW to IS 3589 with the stated lining and coating. Offering LSAW against that sheet needs a written engineering variation.
Stay on ERW when the size is still inside IS 1239 Part 1, 15 to 150 mm NB. A 100 NB Medium distribution line is not an LSAW item. Kanpur plumbing and fire contractors should not see LSAW on those RFQs.
Do not pick LSAW because a brochure said high pressure. Send the material specification, OD, wall, PSL where relevant, tests, and coating. The supplier does not choose the route from the application name.
LSAW versus HSAW on a Kanpur bid sheet
Use the table to keep plate and coil offers off one price cell. Blank cells on a bid sheet are clarifications, not permission to assume the cheaper seam.
| Attribute | LSAW | HSAW (SSAW / spiral) |
|---|---|---|
| Raw material | Steel plate | Hot-rolled steel coil |
| Forming | JCOE / UOE or related plate forming | Coil formed at a helix angle |
| Seam | Straight longitudinal, single or double | Spiral / helical, longer weld per metre |
| Usual OD on product page | 16-48 inch (406-1219 mm) | 16-120 inch (406-3048 mm) |
| Typical standards | API 5L PSL 1/2; owner O&G specs | IS 3589; API 5L when spiral is allowed |
| Typical Kanpur-area duty | Owner-qualified transmission | JJM / AMRUT water mains, piling |
The product-page wall column for LSAW at 16 inch is 8.0 to 20.0 mm, at 24 inch 9.5 to 30.0 mm, at 36 inch 12.7 to 40.0 mm, and at 48 inch 16.0 to 40.0 mm. Those ranges are feasibility notes. The design engineer still sets the ordered wall.
How to specify LSAW on an RFQ
A line that says only SAW pipe invites the cheapest seam. Name LSAW. The comparison page gives a sample oil-and-gas line: LSAW, API 5L PSL2 Grade X52, OD times wall as drawing, about 12 m SRL, bevel ends, external 3LPE, MTC 3.1/3.2, hydrotest and NDE, TPI as named.
- Process: LSAW. Forming route JCOE or UOE if the owner list names one.
- Standard and edition: API 5L (45th, 46th or 47th), IS 3589:2001, or ASTM A672 as drawn.
- Grade and PSL: X42 to X70 and PSL 1 or 2, or Fe 330 / Fe 410 / Fe 450 on an IS 3589 line.
- Size: OD and wall in millimetres. The product page starts LSAW at 16 inch / 406 mm.
- Length: 12 m SRL is the sample on the comparison page; write random or cut-to-length if different.
- Ends: bevel per the WPS, or plain. The API 5L specs block on this site offers a 30 degree bevel as one end finish.
- Coating or lining: 3LPE, 3LPP, FBE, coal-tar enamel, or cement-mortar lining, with cutback and holiday test.
- Documents: EN 10204 3.1 or 3.2, API 5L MPS when that spec applies, plate heat identity.
- Inspection: mill, plus TPI by SGS, Bureau Veritas, Lloyds or TUV when named.
- Delivery: quantity in metres or MT, destination, ex-warehouse Kanpur or FOR named place.
Worked mass example for 16 inch Sch 40
The product page lists 16 inch LSAW at 406.4 mm OD, with a feasibility wall band of 8.0 to 20.0 mm. The pipe schedule chart gives Sch 40 at that NPS as 12.70 mm, which sits inside that band. This check uses that schedule wall. It does not select the wall for a water-main or pipeline design.
Plain-end steel mass on this site is W = (OD − t) × t × 0.02466 kg/m. W = (406.4 − 12.70) × 12.70 × 0.02466 = 393.7 × 12.70 × 0.02466 = 123.30 kg/m. One 12 m plain length is 1,479.6 kg. Twenty-four lengths are 35,510 kg, or 35.51 MT of bare steel.
Cement-mortar lining and 3LPE add mass that this steel formula does not include. The product-page HSAW worked example at 24 inch by 10.0 mm is a different size; do not reuse that 147.86 kg/m figure on a 16 inch line.
There is no LSAW rupee band on the site price lists. Seamless A106 / A53 bands stop at 8 inch on the published table. Send OD, wall, grade, coating, and quantity for an indent proforma.
Common mistakes on LSAW procurement
In practice, a bidder writes SAW and a spiral mill fills the cell. The helical seam is longer per metre, so NDE scope and repair exposure change. The owner list that said LSAW has not been met.
ERW stock at 168.3 mm is offered against a 16 inch LSAW item because both are welded. The product page starts LSAW at 406 mm. Those are different mills and different procedures.
Coating is split across vendors with no cutback or holiday clause. Put surface preparation, system, cutback, repairs, handling, and field joints in one approved schedule.
End geometry is omitted. Ovality, squareness, and bevel protection decide whether the first field weld fits. Agree the measurement method before the plates are formed.
A lower quote is treated as engineering approval for a process swap. Keep LSAW, HSAW, seamless, grade, and PSL under formal deviation control.
Standards and compliance for LSAW
API 5L is the line-pipe specification that often names LSAW as a permitted process. Quote the edition. The 46th-edition announcement and the 47th-edition news release dated 2 June 2026 are the public API pages already used on the API 5L standard page.
IS 3589:2001 allows longitudinal SAW among its construction routes for 168.3 to 2540 mm OD water and sewage pipe. The BIS product manual is the title source for that OD range. Fe 330, Fe 410 and Fe 450 are the grade family on the site IS 3589 page.
ASTM A672/A672M-19 (reapproved 2025) scope 1.1 and 1.2 cover electric-fusion-welded plate pipe, nominally 16 in (400 mm) and larger, wall up to 3 in (75 mm). Grade designates the plate. Class designates heat treatment, radiography, and pressure test. The store abstract requires tension, a transverse guided-weld-bend test, and full-length radiographic examination of each weld.
EN 10219 appears on the product-page standards list for structural hollow applications. Do not use it as a silent substitute for API 5L or IS 3589. IBR Form III-C is not an LSAW certificate; steam pipe, if it ever enters an IBR scope, maps to Form III-A.
Buying LSAW pipe from a Kanpur enquiry
Large-diameter LSAW is indent work. The Bartan Bazar desk raises the mill enquiry; the plate is not a yard bundle sitting next to 50 NB Medium. A Kanpur Dehat bulk-water package and a Panki depot lateral can share one commercial file if the RFQ keeps the LSAW lines on their own sheet.
See LSAW and HSAW pipes, LSAW versus HSAW, steel pipes in Kanpur, and the Kanpur steel market. The product page already works a 24 inch municipal example near Kanpur Dehat; this glossary uses the 16 inch row so the two pages do not share a mass line.
Mill-direct standard grades on the glossary lead-time entry take 14-21 days. Coating, toughness, radiography, and TPI extend that window. Name the stringing date on the RFQ. RP Sales returns a technical and commercial offer inside 4 working hours.
Onward trucks for Lucknow, Agra, Prayagraj, Varanasi, Gorakhpur, Jhansi, Bareilly and Patna need the city route, the PIN, and lifting notes for 12 m, one-and-a-half-tonne pieces. See the Lucknow steel-pipe page and the Patna steel-pipe page for those city runs.
Plate forming routes for LSAW
JCOE forms the plate through J, C and O steps, then expands. UOE forms a U, then an O, then expands. The comparison page treats both as qualified plate-forming sequences. Copy the route the owner list approved.
Plate identity travels from the plate mill through forming and into the pipe stencil. The MTC must show plate heat, pipe number, and the weld procedure qualification. A missing plate heat is a traceability fail on PSL 2 work.
Double-seam LSAW appears on heavier walls when a single plate width cannot close the circumference. Write single or double seam on the RFQ so NDE coverage is priced once.
Expansion after welding is a dimensional step. It is not a substitute for the ovality and end-diameter limits in the project specification. Measure those limits on the finished pipe, not on the plate blank.
Coatings, linings and bevels on large-diameter pipe
The product-page coating list is 3LPE, 3LPP, FBE, coal-tar enamel, and cement-mortar lining. Water packages often want CML inside and a polymeric system outside. Hydrocarbon packages often want 3LPE or FBE. Write both faces.
Cutback, holiday voltage, repair procedure, and field-joint kits belong on the same schedule as the mill coating. A split vendor chain is the failure mode already listed on the product page.
Bevel end geometry follows the WPS. ASME B16.25-2022 is the buttwelding-end standard the bevel glossary uses when the piping class adopts it. API 5L lists a 30 degree bevel as one offered finish. A generic chamfer is not that preparation.
Bare bevels need protection for a Kanpur-to-site haul. Cap or ring the ends so the first field root does not sit on a damaged land.
Inspection points on an LSAW lot
Compare pipe marking and plate or heat identity with the MTC and the release note before the crane takes a 12 m length. Photograph transit damage. Keep nonconforming pieces segregated until the engineer issues a disposition.
Weld examination follows the purchased specification: ultrasonic or radiographic on API 5L PSL 2, full-length radiography on A672 as the store abstract states, and the IS 3589 hydrotest plus project NDE on a water main.
Dimensional checks cover OD, wall, length, ovality, and ends. The comparison page tells the Kanpur buyer to use the project sampling plan, not a single mid-body reading.
A named inspector is a hold point on the indent, not a free extra. SGS, Bureau Veritas, Lloyds or TUV sit on that line when the PO names them. A Type 3.2 countersignature is priced with the witness days.
Where you'll meet this in procurement
You will meet LSAW (Longitudinal Submerged Arc Welded) when choosing process route and product family. Match LSAW (Longitudinal Submerged Arc Welded) to pressure, temperature, corrosion duty, and standard (IS, ASTM, ASME, or API) so the mill route and documentation line up with the application.
Related terms
Related resources
Key points
- LSAW is plate-formed pipe with a straight submerged-arc seam. HSAW is coil-formed pipe with a helical seam.
- The product page lists a usual LSAW OD band of 16 to 48 inch (406 to 1219 mm). Mill range is confirmed on the offer.
- The straight seam does not set a pressure rating. Wall, grade, joint factor and the design code do.
- 16 inch at 406.4 mm OD and 12.70 mm Sch 40 wall is 123.30 kg/m on the site formula.
- Name LSAW, standard, grade, OD, wall, coating and NDE on the RFQ. SAW pipe alone is not a process.
Frequently asked questions
Sources
- ASTM A672/A672M-19 (reapproved 2025). Standard Specification for Electric-Fusion-Welded Steel Pipe for High-Pressure Service at Moderate Temperatures: scope 1.1-1.2, 16 in (400 mm) OD or larger, wall to 3 in (75 mm) (ASTM International)
- API Specification 5L: 46th Edition (announcement). Publication of the 46th edition of Specification 5L, Line Pipe (American Petroleum Institute)
- API Specification 5L: 47th Edition (news, 2 June 2026). API Announces 47th Edition of Foundational Line Pipe Standard (American Petroleum Institute)
- PM/IS 3589:2001. Product Manual for Steel Pipes for Water and Sewage according to IS 3589:2001 (168.3 to 2540 mm Outside Diameter) (Bureau of Indian Standards)
- ASME B36.10M-2018. Welded and Seamless Wrought Steel Pipe: 16 inch NPS = 406.4 mm OD used in the worked example (American Society of Mechanical Engineers)
- Indian Boiler Regulations, 1950. Forms index: III-A steam pipes, III-B tubes, III-C boiler mountings and fittings (Central Boilers Board, Government of India)