Description
Line Pipe for Oil & Gas Transmission
RIGRS supplies API 5L pipeline steel pipe for oil and gas transmission projects, including large-diameter line pipe for onshore pipeline construction and other fluid transportation systems.Outside diameter, wall thickness, and grade are important starting points, but they do not define the pipe manufacturing process.The selected process determines whether the pipe is seamless, longitudinally welded, spirally welded, or resistance welded, and the acceptable process depends on the project specification and service conditions.
Those three numbers matter, but they don’t tell you whether the pipe was made without a weld seam, with a straight longitudinal seam, with a helical seam, or with a resistance-welded seam, and that manufacturing route affects weld integrity, pressure rating headroom, and in some cases whether a given pipe is even acceptable for offshore or sour service under your project’s specification.
We manufacture all four processes — SMLS, LSAW, SSAW, and ERW — across a combined production range of Φ406–1460mm OD, and this page compares the manufacturing processes, applicable size ranges, and key selection considerations.
API 5L Line Pipe for Oil and Gas Transmission
Pipeline steel pipe is normally specified as part of a complete pipeline design rather than purchased by diameter alone. Grade, wall thickness, manufacturing method, pipe length, end finish, inspection requirements and coating all need to match the project specification.
The production range is suitable for a variety of pipeline applications, including:
Crude oil transmission
Natural gas transmission
Onshore oil and gas pipelines
Large-diameter transmission pipelines
Oilfield gathering and transportation systems
Pipeline construction and replacement projects
Industrial fluid transportation
Email: info@rigrs.com
Pipeline Steel Pipe Specifications
| Item | Specification |
| Product | API 5L Pipeline Steel Pipe |
| Pipe Types | SMLS, LSAW, SSAW, ERW |
| Outside Diameter | 406–1460 mm (16″–57.5″) |
| Wall Thickness | 6–50.8 mm (0.24″–2″) |
| Length | 6–12.5 m |
| Material Grade | Grade B–X100 |
| Annual Production Capacity | 200,000 tons |
| Main Application | Oil and gas transmission pipelines |
The actual combination of pipe type, diameter, wall thickness and grade depends on the production process and project requirements.
SMLS, LSAW, SSAW and ERW Line Pipe
SMLS Line Pipe
Seamless line pipe is manufactured without a longitudinal welded seam. It is used where the project specification calls for seamless pipe and the required dimensions fall within the applicable manufacturing range.
SMLS (seamless) line pipe is pierced or extruded from a solid billet with no weld seam at all, which eliminates seam-related failure modes entirely.
The trade-off buyers need to know up front: seamless manufacturing does not scale to the large diameters this page’s overall OD range implies. In practice, SMLS is realistically limited to the smaller end of the diameter spectrum — the large-diameter figures in our production range apply to the welded processes below, not to seamless pipe. SMLS may be specified for smaller-diameter, high-pressure, or critical-service applications where the project specification requires seamless pipe.
When ordering SMLS line pipe, the key information includes API 5L grade, outside diameter, wall thickness, length, end finish, inspection requirements and the required documentation.
LSAW Line Pipe
LSAW, or longitudinal submerged arc welded pipe, is widely used for large-diameter pipeline applications.
Typically via the JCOE or UOE forming process — into a cylinder with a single straight longitudinal seam, then welded internally and externally under submerged arc, with full seam inspection. This is the standard choice for large-diameter, thick-wall, high-pressure transmission lines, and it’s the process most commonly specified for offshore pipelines, where weld integrity control and roundness tolerance matter more than manufacturing cost.
The available production range extends from 406 to 1460 mm outside diameter, with wall thicknesses from 6 to 50.8 mm.
SSAW Line Pipe
SSAW pipe is produced using a spiral submerged arc welding process. It is another option for large-diameter welded pipeline applications.
SSAW (spiral/helical submerged arc welded) pipe forms coil steel into a cylinder along a helical seam rather than a straight one, which lets a narrower coil width produce a larger finished diameter — SSAW uses a helical submerged arc weld, allowing large pipe diameters to be produced from relatively narrow steel plate or coil widths. The process can be economical for large-diameter applications. However, acceptance of SSAW depends on the applicable pipeline standard, operator requirements, service conditions, and project specification. Confirm these requirements before selecting SSAW as an alternative to LSAW.
ERW Line Pipe
ERW, or electric resistance welded pipe, is manufactured using an electric resistance welding process. It can be used for line pipe applications where the required diameter, wall thickness and grade are suitable for ERW production.
ERW (electric resistance welded) pipe is roll-formed from coil into a cylinder with a straight seam closed by high-frequency electric resistance welding, without filler metal. It’s the most economical of the four processes at small-to-medium diameter, and modern high-frequency ERW (HFW) with in-line ultrasonic seam inspection addresses most of the weld-quality concerns associated with older, lower-frequency ERW pipe from decades past. That said, some pipeline codes and operator specifications still carry legacy restrictions on ERW for high-pressure or sour service, a holdover from that older pipe’s field failure history.
Email: info@rigrs.com
JCOE LSAW Steel Pipe Production Line
The RIGRS is equipped with an established JCOE longitudinal submerged arc welded steel pipe production line for large-diameter welded pipe manufacturing.
The production line covers the main stages from steel plate preparation and forming through welding, expansion, finishing, straightening and inspection.
Main equipment includes:
Steel plate milling machine
Steel plate prebending machine
Steel pipe forming machine
Three-wire internal welding machine
Four-wire external welding machine
Steel pipe expanding machine
Steel pipe finishing machine
Steel pipe straightening machine
Non-destructive testing equipment
Physical and chemical test equipment
This equipment configuration provides dedicated processing and inspection stages for large-diameter LSAW pipe rather than relying on a single forming and welding operation.
RIGRS Pipeline Steel Pipe Manufacturing Process
Steel Plate Milling
The steel plate edges are prepared using a dedicated milling machine before forming. Edge preparation is an important part of the longitudinal welding process because the prepared edges form the longitudinal joint of the finished pipe.
Plate Prebending
After edge preparation, the plate is prebent before entering the main forming process. This prepares the plate for controlled forming into the required pipe geometry.
JCOE Forming
The prepared steel plate is progressively formed into a pipe using the JCOE forming machine.
The forming stage establishes the basic diameter and geometry of the pipe before longitudinal welding.
Internal Submerged Arc Welding
The longitudinal joint is welded internally using a three-wire submerged arc welding machine.
The internal weld forms one part of the longitudinal welded joint and is subject to the applicable inspection requirements.
External Submerged Arc Welding
External welding is carried out using a four-wire submerged arc welding machine.
The internal and external welding operations together form the longitudinal weld of the LSAW pipe.
Pipe Expansion
After welding, the pipe passes through a dedicated expanding machine. Expansion provides a controlled dimensional correction stage before final finishing and inspection.
Finishing and Straightening
The finished pipe is processed through dedicated finishing and straightening equipment to achieve the required dimensional condition.
Non-Destructive Testing
The production facility is equipped with a full set of non-destructive testing equipment.
NDT requirements depend on the applicable API 5L specification, purchase order and project inspection plan. The inspection scope can be defined according to the required acceptance criteria.
Physical and Chemical Testing
Physical and chemical testing equipment is available for material and product testing.
The testing scope is determined by the applicable standard and purchase specification. Material documentation and test results can be provided according to the agreed order requirements.
Large-Diameter Pipeline Steel Pipe
With an outside diameter range of 406–1460 mm, the production capability covers a broad range of large-diameter pipeline requirements.
Quality Control and Inspection
Every joint should ship with a mill test certificate (MTC) showing chemical composition and mechanical test results traceable to heat number, along with hydrostatic test results per API 5L requirements for the applicable PSL. PSL2 orders carry additional mandatory testing — Charpy V-notch impact testing at the specified temperature, and stricter ultrasonic and/or radiographic inspection of the weld seam on LSAW, SSAW, and ERW pipe. For large orders tied to a specific pipeline project, confirm whether your project requires third-party inspection (SGS, BV, TÜV, or a client-nominated inspector) witnessing mill tests before shipment — If third-party inspection is required, the inspection agency and inspection scope should be confirmed before production or at the stage specified in the purchase order.
Depending on the purchase specification, the quality documentation may include:
Material Test Certificate (MTC)
Material and heat identification
Chemical analysis
Mechanical test results
Dimensional inspection records
Weld inspection records
NDT records
Required pressure or other specified test records
Product marking and traceability records
Packing and shipping documentation
Third-party inspection records, where required
200,000 Tons Annual Production Capacity
The stated annual production capacity is 200,000 tons.For large pipeline projects, production capacity becomes important when several pipe sizes, wall thicknesses or grades are included in the same order.
A project may involve different pipe specifications within one material schedule, together with requirements for inspection, marking, coating, packing and staged delivery. Providing the complete schedule at the quotation stage allows the production plan and delivery requirements to be reviewed together.
RIGRS Pipeline Steel Pipe FAQ
Q1: Is ERW pipe suitable for high-pressure gas transmission?
A: Modern high-frequency ERW with in-line ultrasonic inspection performs well in many transmission applications, but some codes and operator specifications still restrict ERW in high-pressure or sour service based on older ERW pipe’s field history. Check your project’s specific code requirements before specifying ERW for a high-consequence line.
Q2: What does PSL2 add beyond PSL1?
A: PSL2 requires mandatory Charpy impact testing, tighter chemical composition limits affecting weldability and toughness, and stricter non-destructive testing of the weld seam. It’s typically specified for offshore lines, sour service, and higher-pressure transmission pipelines.
Q3: What sizes of API 5L pipeline steel pipe are available?
A: The stated production range is 406–1460 mm (16″–57.5″) outside diameter, with wall thicknesses from 6–50.8 mm (0.24″–2″).
Q4: What is the maximum pipe diameter?
A: The stated maximum outside diameter is 1460 mm (57.5″).
Q5: What is the maximum wall thickness?
A: The stated wall thickness range is 6–50.8 mm (0.24″–2″).
Q6: What pipe lengths are available?
A: The stated production length is 6–12.5 m.
Q7: Does the factory have JCOE LSAW production equipment?
A: Yes. The production line includes steel plate milling, prebending, JCOE forming, three-wire internal welding, four-wire external welding, pipe expansion, finishing and straightening equipment.
Q8: Does the factory have NDT and laboratory testing capability?
A: The factory is equipped with a full set of non-destructive testing equipment as well as physical and chemical test equipment. The exact testing methods and acceptance criteria are determined by the applicable specification and purchase order.
Q9: Can the pipe be supplied with MTC and inspection documentation?
A: The required material and inspection documentation can be specified as part of the purchase order. The exact documentation package should be confirmed according to the applicable project requirements.
Request a Quotation
For an API 5L pipeline steel pipe quotation, send us your required OD, wall thickness, grade, PSL level with the project quantity and delivery destination.
The engineering and production team can then review the required pipe type, dimensions, grade, manufacturing process and inspection scope before preparing the quotation.
Email: info@rigrs.com
| Material | api 5ct J55 K55 N80 L80 API 5L x42 x52 x60 x70 ; H40 C95 N80I N80 Q C-90 T-95 P110 Q-125 |
| Size | Size 1.050″ to 20″ Outside Diameter 26.67 mm to 508 mm |
| Standard | API5L , API 5CT API 5DP |
| Certificates | API5L, API 5L ISO 9001:2008,SGS, BV,CCIC |
| Wall thickness | 2.87~16.13 MM |
| Surface Treatment | black paint, varnish, oil, galvanized, anti corrosion coatings |
| End Type | LTC STC EUE NUE VAM XC NPT |
| Pipe Ends | Under 2 inch plain end. 2 inch and above Beveled. Plastic caps (small OD) ,Iron protector (large OD) |
| Pipe Length | 1. R1: 4.88~7.62M. |
| 2. R2:7.62~10.36M | |
| 3.R3:10.36~14.63M |
