Pipes used in offshore engineering primarily include seabed OCTG pipes, long-distance seabed transport pipes, and internal connection pipes for offshore oil and gas fields (seabed gathering and transportation pipelines, risers, and working connection pipelines). These pipes are required to possess high strength, excellent toughness, and strong resistance to seawater corrosion.

Steel pipe grade | seamless pipe | ||
yield strength Rt0.5/MPa | strength of extension Rm/MPa | yield ratio Rt0.5/Rm | |
L245NO OR BNO | 245~450 | 415~760 | ≤0.93 |
L290NO OR X42NO | 290~495 | 415~760 | ≤0.93 |
L320NO OR X46NO | 320~520 | 435~760 | ≤0.93 |
L360NO OR X52NO | 360~525 | 460~760 | ≤0.93 |
L390NO OR X56NO | 390~545 | 490~760 | ≤0.93 |
L415NO OR X60NO | 415~565 | 520~760 | ≤0.93 |
L450QO OR X65QO | 450~570 | 535~760 | ≤0.93 |
L485QO OR X70QO | 485~605 | 570~760 | ≤0.93 |
L555QO OR X80QO | 555~675 | 625~825 | ≤0.93 |

Product performance standards:
API SPEC 5L 《Ordering of PLS2 steel pipes for offshore service》
SY/T10037-2002《Undersea Pipeline System Code》
GB 712-2000 《Structural steel for the hull》
DNV-OS-F101-2000 《Undersea Pipeline System Specifications》
Product Features:
It exhibits excellent corrosion resistance, weldability, and outstanding low-temperature impact properties.
Product Specification Range:
Outer diameter: Φ17.1 mm–Φ219.1 mm; wall thickness: 2.3 mm–40.0 mm