High-integrity steel pipe for offshore risers, subsea flowlines, and export pipelines. DNV-OS-F101 compliant with CWC coating, CTOD-tested welds, and full material traceability for the most demanding marine environments.
Offshore oil and gas development demands the highest standards of pipe quality, material integrity, and manufacturing precision. At Sino East Steel, we supply DNV-OS-F101 certified line pipe for every offshore application — from shallow-water platform risers to ultra-deep subsea tiebacks. Our offshore pipe manufacturing program includes enhanced NDT, CTOD fracture toughness testing, tighter dimensional control, and full compliance with major operator specifications.
Risers are the critical link between the seabed and surface facilities, subjected to the most extreme combination of internal pressure, external hydrostatic pressure, wave and current loading, and vessel motion. Our seamless and LSAW riser pipe is manufactured with the tight ovality tolerances, high fatigue performance, and consistent mechanical properties required for SCR (Steel Catenary Riser), TTR (Top Tensioned Riser), and hybrid riser systems.
Subsea flowlines transport well fluids from subsea trees to processing facilities, while export lines carry processed oil and gas to shore. Both require pipe with excellent collapse resistance, sour service capability where H₂S is present, and reliable anti-corrosion protection. Our 3LPE/3LPP coated pipe with optional CWC provides the complete subsea pipeline solution.
S-lay installation, using a stinger at the stern of the pipelay vessel, is efficient for water depths up to approximately 2000m. J-lay, deploying pipe near-vertically from a tower, is preferred for deep and ultra-deep water where the lower bending strains reduce installation stresses. Our pipe is qualified for both methods, with mechanical properties optimized for the specific installation and operational loads.
| Standard | Scope | Key Requirements |
|---|---|---|
| DNV-OS-F101 | Submarine Pipeline Systems | Full design, materials, installation, and operation code |
| API 5L PSL2 | Line Pipe (Offshore Supplementary) | CTOD, CVN, DWTT, tighter chemistry and dimensions |
| API RP 1111 | Design of Offshore Pipelines | Limit state design methodology for offshore systems |
| ISO 21809-1 | External Coatings (3LPE/3LPP) | Coating application and testing for buried/subsea pipe |
| ISO 21809-5 | External Concrete Coating | CWC application, density, and thickness requirements |
| NACE MR0175 | Sour Service Materials | H₂S-resistant materials for sour hydrocarbon service |
DNV-certified LSAW line pipe for subsea flowlines and export pipelines. CTOD tested with tight dimensional control.
Spiral welded pipe with concrete weight coating for subsea stability and mechanical protection.
Seamless pipe for SCR and TTR riser applications. Superior fatigue performance and tight ovality control.
Multi-layer anti-corrosion coating for subsea pipelines. 3LPP for high-temperature flowlines up to 110°C.
API 5CT casing for offshore wells. Premium connections, sour service grades, and high collapse resistance.
High-yield weldneck and swivel flanges for offshore piping. A694 F52-F70, RTJ and RF facing, full traceability.
Contact our offshore engineering team for DNV-qualified pipe specifications, CTOD test data, and a detailed project quotation.
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