API 5L
/glossary/api-5lAPI specification for seamless and welded steel line pipe in oil and gas transportation.
API 5L is the line-pipe specification a Kanpur oil-terminal or cross-country contractor names when the pipeline document calls for it, not when a water BOQ says Fe 410. The site standards page still lists the 45th Edition (2012) or later; API announced the 46th edition and, on 2 June 2026, the 47th. Copy the edition the engineer adopted. Offers leave the Basanti Nagar yard (208014) on an ex-warehouse Kanpur basis. Budget GST at 18% extra on the tube line; the tax invoice applies the rate in force.
In detail
API Specification 5L covers seamless and welded steel line pipe for pipeline transportation. The grades this site tabulates run B through X70 by specified minimum yield strength, with X42 at 289 MPa and X70 at 483 MPa. The adopted edition sets two product specification levels, PSL 1 and PSL 2. Sour service is a project add-on: name the H2S environment and the ISO 15156 or Annex H route the operator selected. The designation alone does not set pressure, fluid, or location class.
What API 5L is, and what it is not
API Specification 5L is the American Petroleum Institute product standard for seamless and welded steel line pipe. The 2 June 2026 news release for the 47th edition states that Spec 5L covers manufacture of seamless and welded steel pipe: material, process, inspection, testing, marking and traceability.
It is not IS 1239 utility tube. It is not IS 3589 water and sewage pipe. It is not SA192 or SA210 boiler tube. A matching OD does not convert a municipal Fe 410 length into line pipe.
ISO 3183 is the ISO counterpart for steel pipe in pipeline transportation systems. Treat it as a related document. Substitute it only when the tender names it.
If a proposed length also sits inside an Indian boiler boundary, the approved design and the competent authority set the material and the component class. The DPIIT forms index maps a steam pipe to Form III-A, a tube to Form III-B, and a mounting or fitting to Form III-C.
Who should buy API 5L, and who should stay on water pipe
Buy API 5L when the approved pipeline specification names it. Grade and wall come from the pressure calculation, design factor, diameter, temperature, corrosion allowance, installation loads, and fracture-control basis. Do not assign X42 to gathering lines or X70 to high-pressure work from a website ladder.
Kanpur-area hydrocarbon fuel lines and depot laterals around Panki use this specification when the owner list says so. A sugar-mill utility header that the drawing calls IS 1239 Medium stays on that class. A JJM rising main that the consultant called IS 3589 Fe 410 stays on that grade.
Do not treat PSL 2 as a default for every stringing lot. Service, toughness, NDE, sour conditions, offshore conditions, and the owner ITP select the level. A low-pressure label does not approve PSL 1.
Sour-service fitness does not follow from the words API 5L or PSL 2. Write the H2S envelope and the exact ISO 15156 / Annex H material route. A PSL stamp also does not open an IBR steam-pipe route.
API 5L grade comparison for a Kanpur RFQ
Grade letters encode specified minimum yield strength. That number is one design input. Edition, PSL, size, wall, and product form still have to be read from the adopted specification. The table repeats the site standards page.
| Grade | Yield min (MPa) | Tensile min (MPa) | PSL 2 CVN | Buyer action |
|---|---|---|---|---|
| X42 | 289 | 414 | Project-specific | Copy the approved grade and PSL |
| X52 | 359 | 455 | Project-specific | Copy the approved grade and PSL |
| X60 | 414 | 517 | Project-specific | Copy the approved grade and PSL |
| X65 | 448 | 531 | Project-specific | Copy the approved grade and PSL |
| X70 | 483 | 565 | Project-specific | Copy the approved grade and PSL |
A higher X grade can change the calculated wall for a defined design. Procurement cannot make that swap from yield alone. Return any grade or wall change to the pipeline engineer and reconcile welding, toughness, NDE, coating, and construction.
How to specify API 5L on an RFQ
Line-pipe enquiries fail when they say API 5L X52 and omit PSL, process, coating, and toughness temperature. Write the pipeline spec line. Send that pack on the RFQ.
- Standard and edition: API 5L, plus 45th, 46th, or 47th as the project document states.
- Grade: B, X42, X46, X52, X56, X60, X65, or X70 exactly as the design uses.
- PSL: PSL 1 or PSL 2 as the approved pipeline specification selects.
- Process: seamless (S), ERW, LSAW, or SSAW / HSAW.
- Size: OD and wall, or NPS and schedule, with D/t if the spec uses it.
- Length: SRL 6-12 m or DRL 11-13 m, random or cut-to-length.
- End finish: plain, 30 degree bevel, or threaded with couplings.
- Coating: external FBE, 3LPE or 3LPP; internal epoxy or bare.
- Documents: API 5L MPS, EN 10204 3.1 or 3.2, plus the sour-service wording the operator named.
- Inspection: mill, or named TPI (SGS, Bureau Veritas, Lloyds, or TUV) when the PO requires it.
- Metre or MT quantity, the destination PIN, and whether the lot is collected at the Kanpur yard or hauled FOR a named place.
Worked mass example for 8 inch NPS Sch 40
The pipe schedule chart lists 8 inch NPS (DN 200) as OD 219.1 mm and Sch 40 wall 8.18 mm. Theoretical mass is W = (OD − t) × t × 0.02466 kg/m.
W = (219.1 − 8.18) × 8.18 × 0.02466 = 210.92 × 8.18 × 0.02466 = 42.55 kg/m. Forty double-random lengths of 12 m are 480 m, so 480 × 42.55 = 20,424 kg, or 20.424 MT of bare steel.
3LPE or FBE mass sits on top of that steel figure. Do not use the bare-pipe tonne for coated freight. A schedule number alone does not fix a pressure rating; size, wall, material allowable stress, and the design code do.
There is no API 5L rupee band on the site price lists. The seamless A106 / A53 band for 8 inch Sch 40 is ₹74-90 per kg ex-warehouse Kanpur as of 24 May 2026. That steel line would be 20,424 × 74 = ₹15,11,376 to 20,424 × 90 = ₹18,38,160 before GST and freight, and it is a different product from API 5L line pipe. Ask for a proforma on grade, PSL, OD, wall, and coating.
Common mistakes on API 5L procurement
In practice, PSL is picked from price. Toughness, NDE, chemistry, and traceability then arrive on the wrong level, and the owner inspector holds the stringing lot.
Grade X65 PSL 1 is treated as interchangeable with X52 PSL 2. Grade is strength. PSL is the test and documentation set. They do not replace each other.
ERW is offered against an LSAW large-diameter item, or seamless is offered against a spiral-weld trunk. Process is a specified field on the pipeline specification.
Sour service is assumed from the words API 5L. State the H2S environment and the complete ISO 15156 / Annex H route. See NACE MR0175.
IS 3589 water pipe is delivered against an API 5L line because the OD matched. Authority engineers reject that swap at stringing.
Standards and compliance for API 5L
The governing line-pipe document is API Specification 5L. This page still cites the 45th Edition, 2012, or later on the site specs block. Quote the edition written in the pipeline specification. Do not mix 45th, 46th, and 47th requirements on one PO.
API’s 46th-edition announcement, retrieved 2026-09-03, updates mill jointers, pipe-end squareness, and hardness testing on PSL 2 pipe for sour and offshore service. It also adds a strain-based design annex for PSL 2 pipe that needs longitudinal plastic strain capacity.
The 47th-edition news release dated 2 June 2026 adds requirements across more than 15 topic areas, including high-frequency weld pipe quality and pipe used in CO2 transport. It also names sour-service requirements, impact toughness, lamination control, and sulfide-stress-cracking tests among the updates.
ISO 3183 remains the ISO counterpart. NACE MR0175 / ISO 15156 applies where the approved sour-service design invokes it. TPI by SGS, Bureau Veritas, Lloyds, or TUV is coordinated when the RFQ names the agency.
Buying API 5L line pipe from Kanpur
Kanpur-origin API 5L work is mill-direct line pipe, handled on the same commercial desk that prices IS 1239 stock. A Panki depot lateral and a Unnao water-main indent can share one enquiry list; keep the API 5L lines on their own page of the RFQ.
The seamless pipes in Kanpur hub lists hydrocarbon fuel transport in oil terminals as one local duty. That duty still needs the pipeline specification, not a yard nickname. See the API 5L standard page and PSL 1 versus PSL 2.
Stock items on the glossary lead-time entry clear in 3-7 days. A mill-direct standard grade sits in the 14-21 day band on that same entry. Line-pipe coating, toughness packages, and TPI extend that window. Name the need-by date on the RFQ.
Outstation stringing lots for Lucknow, Agra, Prayagraj, Varanasi, Gorakhpur, Jhansi, Bareilly, and Patna should state the city route and PIN. The FAQ already records daily coverage from Kanpur across Uttar Pradesh, Bihar, Madhya Pradesh, Delhi NCR, and Uttarakhand.
PSL 1 versus PSL 2
PSL 1 is the base product specification level. The site standards page states that it covers chemical composition, mechanical properties, and dimensional tolerances, and that it does not require mandatory notch toughness testing or NDE.
PSL 2 adds mandatory fracture-toughness requirements (Charpy V-notch), restricts carbon equivalent for weldability, requires NDE (ultrasonic or radiographic), and mandates full traceability. PSL 2 pipe is stamped with the grade and the PSL level.
The project selects the level from its risk, design, regulatory, service, toughness, inspection, and documentation basis. Reproduce the adopted requirements on the PO. A cross-country label is not a selection rule.
Carbon-equivalent figures already tabulated on the site standards page for PSL 2 include CEIIW 0.43% max on X42 to X52, 0.45% max on X56 to X65, and 0.46% max on X70. Copy the edition table, not a memory of those caps.
Sour service, coating, and documents
Annex H on the 46th-edition announcement is the sour-service add-on for PSL 2 pipe. Annex J is the offshore add-on. Neither annex arrives because the stencil says X52. The operator must name the annex, the hardness method, the test locations, and the acceptance basis.
NACE MR0175 / ISO 15156 Parts 1 to 3 decide whether the metal may sit in a defined H2S envelope. They do not set NPS, schedule, or end finish. Order the product standard first, then add the sour-service route.
External FBE, 3LPE, or 3LPP, and internal epoxy or bare, are ordered finishes on the site specs block. Bare steel mass is not coated mass. Name the coating system, cutback, holiday test, and field-joint kit if the line is buried.
An RP Sales truck already leaves with an MTC in the envelope. Line pipe often needs EN 10204 3.2 and a named TPI release as well. Form III-C is not the line-pipe certificate; it is the IBR form for boiler mountings and fittings.
Process route on an API 5L order
The site specs list seamless (S), ERW, LSAW, and SSAW as permitted manufacturing routes. The pipeline specification selects the route after its diameter, wall, fracture, welding, inspection, and construction checks.
Large-diameter, heavier-wall transmission often names LSAW. Helical SAW is a different seam. See LSAW versus HSAW before a mill offers spiral against a longitudinal item.
Seamless A106 Grade B is not a silent substitute for API 5L Grade B. Chemistry, toughness, PSL, and marking differ. The A106 versus IS 1239 page is a different comparison; keep API 5L on its own RFQ page.
Marking, heat identity, and the MPS must match the pipe stencil, the MTC, and the dispatch challan. Photograph the stencil at the Kanpur loading bay when TPI is not sitting on the truck.
Where you'll meet this in procurement
You will meet API 5L when a buyer, consultant, or mill quote names a governing specification. Confirm which revision applies, what tests the standard requires, and whether the grade on the MTC actually matches the API 5L call-out on the RFQ before you lock commercial terms.
Related terms
Related resources
Key points
- API 5L is line pipe for oil and gas, not IS 1239 utility tube and not SA192 boiler tube.
- API announced the 46th edition of Spec 5L, and on 2 June 2026 announced the 47th. Quote the project edition on the PO.
- X42 yield is 289 MPa; X70 yield is 483 MPa. PSL is a test set, not a pressure upgrade.
- 8 inch NPS Sch 40 is 219.1 mm OD by 8.18 mm wall and 42.55 kg/m on the site schedule chart.
- Write PSL, process, coating, and sour-service wording. Grade alone is not a complete RFQ.
Frequently asked questions
Sources
- API Specification 5L: 46th Edition (announcement). Publication of the 46th edition of Specification 5L, Line Pipe: mill jointers, end squareness, PSL 2 sour-service and offshore hardness, strain-based design annex (American Petroleum Institute)
- API Specification 5L: 47th Edition (news, 2 June 2026). API Announces 47th Edition of Foundational Line Pipe Standard: HFW quality, CO2-transport, sour-service and toughness updates named (American Petroleum Institute)
- ISO 3183. Petroleum and natural gas industries: Steel pipe for pipeline transportation systems (International Organization for Standardization)
- NACE MR0175 / ISO 15156. Materials for use in H2S-containing environments in oil and gas production (NACE International / International Organization for Standardization)
- 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)
- ASME B36.10M-2018. Welded and Seamless Wrought Steel Pipe: NPS and DN size language used by the site pipe schedule chart (American Society of Mechanical Engineers)