Description
Direct Mill Supply, No Broker Markup — Every LSAW pipe is rolled, welded, and inspected in-house from our own steel plate, eliminating third-party material gaps.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | LSAW Carbon Steel Pipe for Offshore Platform Structures |
| Product Type | Longitudinally Submerged Arc Welded (LSAW) Steel Pipe |
| Steel Grade | 10#, 20#, Q235, Q345B, Q345C, ASTM A53A, A53B, A106B, API 5L Gr.B, X42, X46, X52, X60, X65, X70, X80, ST37, ST37-2, DIN 1629 ST35, 15CrMo, Cr5Mo |
| Standard | API 5L, ASTM A53, A106, BS, DIN, GB, JIS |
| Section Shape | Round |
| Outer Diameter | 21.3–1420 mm |
| Wall Thickness | 2.11–300 mm |
| Length | 6 m / 6.4 m / 12 m (or as required) |
| Technique | LSAW / JCOE |
| Surface Treatment | Black / Oiled / Non-oiled |
| Tolerance | OD ±1%, WT ±10% |
| Ends | Plain / Beveled |
| Processing Service | Welding, Punching, Cutting, Bending, Decoiling |
| Application | Offshore platform structures, oil & gas pipelines, structural engineering |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Offshore Energy | Jacket leg pipes, brace members, conductor casings for offshore drilling platforms |
| Oil & Gas | Onshore and offshore transmission pipelines, gathering lines, flow lines |
| Industrial Infrastructure | Pipe rack stanchions, process support columns, structural frames in petrochemical plants |
| Marine Construction | Dock piling, fender systems, mooring dolphin structures |
What Wall-Thickness Deviation Costs on an Offshore Jacket Order
A two-ton shortfall per container turns a routine delivery into a port-side nightmare.
When LSAW pipes arrive at Jakarta or Lagos with wall thickness below the specified negative tolerance, the entire shipment gets flagged. Third-party inspectors reject the SAW weld UT results, and the pipes sit in customs limbo for weeks while your project schedule burns through idle crane time and standby crew costs. [NEED_CITE: API 5L dimensional tolerance requirements for line pipe]
The root cause is fragmented sourcing — the fabricator buys steel plate from one mill, sends it to a separate rolling shop, then subcontracts the welding. No single entity owns the quality chain. When tolerances slip, everyone points fingers, and the buyer pays the rework.
Matching Large-Diameter Pipe to Jacket Structural Loads
Offshore platform jackets demand pipes that carry both axial compression from deck loads and lateral forces from wave impact. The JCOE forming process used for these LSAW pipes ensures uniform roundness across the 21.3–1420 mm diameter range, which matters when you’re welding brace-to-chord connections that must align within millimeter tolerances. API 5L X65 and X70 grades deliver the yield strength needed for deepwater leg sections, while Q345B and Q345C serve shallower coastal structures where cost efficiency takes priority. Our integrated mill-to-pipe production means every heat number traces back to the original slab chemistry — no guessing games when the classification society asks for documentation.
Engineering Compliance for Marine and Pressure Applications
Offshore projects operate under strict classification rules — DNV, ABS, Lloyd’s Register all require full material traceability and certified welding procedures. The LSAW Carbon Steel Pipe for Offshore Platform Structures we supply meets API 5L for pressure-containing pipelines and ASTM A53/A106 for structural and mechanical applications. For European offshore developments, EN 10219 compliance ensures the hollow sections meet dimensional and mechanical requirements for structural use. [NEED_CITE: EN 10219 cold-formed welded structural hollow sections] Wall thickness up to 300 mm covers heavy-wall conductor casings and pile sleeves, while the ±10% WT tolerance aligns with standard mill practice for submerged arc welded products. Beveled ends ready for field welding eliminate secondary machining at the fabrication yard.
Steel Grade Selection: Carbon vs. High-Strength Low-Alloy
The choice between Q235 and API 5L X80 isn’t just about cost — it’s about whether your structure needs ductility for seismic zones or higher yield for reduced wall thickness in deepwater applications. Standard carbon grades like 20# and A106B work well for non-critical structural members and low-pressure piping. High-strength grades like X65 and X70 reduce material weight while maintaining pressure integrity, critical for offshore risers and export pipelines. Alloy grades such as 15CrMo and Cr5Mo handle elevated temperatures in process piping above 400°C. The JCOE process with dual-sided submerged arc welding produces a clean, defect-free weld seam that passes radiographic and ultrasonic testing without the laminar defects sometimes seen in spiral-welded alternatives.
Hidden Costs of Unverified Material Sources
Pipes sourced through trading companies often carry certificates that don’t match the actual product — a common scenario where the MTC shows X65 chemistry but the pipe tests as X52. [NEED_CITE: material traceability requirements for offshore structural steel] When classification societies discover this during fabrication audits, the entire batch gets rejected. Beyond the material cost, you face project delays, re-procurement at spot market prices, and potential liability if non-conforming pipe reaches the installation site. Our vertically integrated production eliminates this risk — the same facility that rolls the plate welds the pipe and issues the certificate.
Why Integrated Mill Production Matters for Offshore Buyers
We operate our own steel mill with three production lines and over 2,800 raw material specifications, meaning we control chemistry from slab to finished pipe. Every LSAW Carbon Steel Pipe for Offshore Platform Structures undergoes in-house ultrasonic testing of the weld seam and dimensional verification before coating. Our welding procedures are certified to AWS D1.1 and EN ISO 15614 standards, with qualified welders assigned to each production campaign. For projects requiring third-party verification, we coordinate SGS, BV, or Lloyd’s inspections at any hold point — from plate receipt through final coating. This single-source accountability means one quality system, one set of documentation, and one point of contact when questions arise during fabrication or installation.
Documentation & Compliance
- Mill Test Certificate documenting API 5L X65 chemical composition and mechanical properties per heat number
- CE Certificate confirming EN 10219 compliance for structural hollow sections exported to European markets
- ISO 9001 Quality Management System certificate covering the full LSAW pipe production process
- Third-party inspection reports from SGS or BV covering dimensional checks, NDT results, and coating thickness
- Material traceability records linking each pipe to its original steel plate heat number and rolling schedule
- Export documentation including packing list, bill of lading, and certificate of origin for customs clearance
Packaging, Loading & Delivery
- LSAW pipes bundled with steel strips and edge protectors to prevent coating damage during ocean transit
- Black or oiled surface treatment applied per customer specification to prevent corrosion during storage and shipping
- 12-meter lengths loaded in 40-foot open-top containers with custom cradles for oversized diameters above 600 mm
- Heat number and steel grade stenciled on each pipe end for site identification and traceability verification
- FOB, CIF, or DDP delivery terms available with professional lashing plans for heavy-wall pipe sections
- Beveled ends protected with plastic caps to prevent damage to welding preparation during handling
Getting Your Offshore Pipe Quotation Started
Submit your project specifications including outer diameter, wall thickness, steel grade, quantity, and destination port. We respond within 24 hours with a detailed quotation covering material, fabrication, coating, and logistics costs, along with a production timeline and shop drawing review schedule. For non-standard dimensions or custom lengths, our engineering team provides feasibility assessment and alternative proposals based on your structural requirements.
Frequently Asked Questions
Q: What is the difference between API 5L and ASTM A53 for offshore applications?
A: API 5L governs line pipe for pressure transmission in oil and gas pipelines, with grades from Gr.B to X100 specifying minimum yield strength. ASTM A53 covers seamless and welded steel pipe for general mechanical and pressure applications, with Grade A and B designations. For offshore platform conductor pipes and transmission lines, API 5L is typically specified; for structural members and non-pressure piping, ASTM A53 applies.
Q: How do you ensure material traceability from steel plate to finished pipe?
A: Each steel plate receives a unique heat number during melting, which is tracked through rolling, cutting, forming, and welding. The finished LSAW pipe carries the same heat number, and the Mill Test Certificate documents the complete chain from slab chemistry through final mechanical testing.
Q: Can you produce non-standard diameters or wall thicknesses for specific engineering drawings?
A: Yes. Our JCOE forming process covers outer diameters from 21.3 mm to 1420 mm and wall thicknesses up to 300 mm. For dimensions outside standard ranges, we review your engineering drawings and provide feasibility assessment with alternative proposals if needed.
Q: What surface treatment options are available for offshore marine environments?
A: Standard options include black (uncoated), oiled for temporary rust prevention, and non-oiled for immediate coating application. For offshore service, we coordinate third-party applicators for 3PE, FBE, or epoxy coating systems per project specifications.
Q: How are large-diameter LSAW pipes packed for export shipment?
A: Pipes above 600 mm diameter are loaded in open-top containers or on flat racks with custom steel cradles and lashing to prevent movement during ocean transit. Smaller diameters are bundled in standard containers with edge protectors to preserve surface condition.
Start Your Offshore Pipe Procurement
Send your project drawings and specifications to receive a detailed quotation with Mill Test Certificate documentation and production timeline.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjystructure.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjystructure.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
