“Super-Large Seamless Pipe Unit” (Project 630)

We witnessed the launch of the extra-large diameter continuous pipe rolling unit (industry-known as the “Super-Large Seamless Pipe Unit” or “Project 630”).

Key Parameters: The world’s first continuous rolling line for seamless pipes featuring the largest diameter and a three-roll retained mandrel system; outer diameter (OD) range of Φ323.8–630mm, wall thickness of 7.2–65mm; designed annual capacity of 800,000 tons; officially commissioned on July 28, 2026.

On-site view of the Super-Large Seamless Pipe Unit

the biggest seamless steel pipe rolling unit

I. Core Competitive Advantages

1. Disruptive Process Advantages (Key Highlight)

Existing domestic production of Φ426–630mm extra-large diameter seamless pipes primarily relied on the hot-expansion process (heating and expanding smaller pipe billets);
This line achieves forming via a single continuous rolling process, eliminating the need for secondary hot expansion:
Microstructure uniformity, wall thickness consistency, and dimensional accuracy are vastly superior to hot-expanded pipes;
Eliminates one heating stage, resulting in lower energy consumption, higher yield rates, and significantly reduced per-unit production costs;
Avoids common issues associated with hot-expanded products—such as delamination, inner surface defects, and performance fluctuations—thereby meeting stringent qualification standards for high-end oil, gas, and boiler applications.

2. Equipment and Rolling Technology Advantages

Features a 6-stand, double-side opening FQM (Fine Quality Mill) three-roll retained mandrel continuous rolling mill—the world’s first application at the Φ630mm scale—breaking through limits for rolling extra-large diameter, ultra-thin-walled pipes (7.2mm wall thickness for large-diameter pipe);
Equipped with a vertical conical-roll piercer, in-line residual heat treatment, and a comprehensive intelligent inspection system;
Integrates AI-driven Industrial Internet with one-touch fully automated rolling; reduces hot-rolling crew size by nearly 50% while enhancing production stability and consistency;
Seamlessly bridges the gap with existing production lines (where the previous continuous rolling limit was Φ380mm), completing the full specification range from 380mm to 630mm.

3. Product and Industrial Chain Advantages

Covering the entire process—from in-house steelmaking to tube billets, hot rolling, heat treatment, and deep processing—the facility enables stable production of:
Oil and gas casing/line pipe, subsea pipelines, high-pressure boiler tubes, pressure vessel tubes, structural tubes for construction machinery, and high-pressure gas cylinder tubes;
Compatibility with special materials such as P91/P92 heat-resistant steel, high-strength line pipe steel, and high-sulfur-resistant oil casing.

4. Scale Advantages

The only large-scale continuous rolling production line in China for extra-large seamless pipes (Φ630mm), distinguishing itself from the low-capacity, high-cost models of extrusion units; maximum capacity reaches 1.2 million tons, enabling large-volume exports and supply assurance for major domestic projects.

II. Filling Key Gaps for Domestic Steel Mills (Addressing Industry Shortcomings)

1. Process Route Gap: Establishing a “Large-Scale Continuous Hot Rolling” Pathway for Extra-Large Diameters

Previous domestic landscape:
≤380mm: Mature continuous rolling mill technology;
380–630mm range: Almost entirely reliant on hot expansion, extrusion, or forging;
Hot expansion: Poor quality consistency; often rejected by high-end design institutes and overseas clients;
Extrusion units: Very low batch capacity and extremely high investment/production costs; unsuitable for large-scale supply;
The existing unit fills the domestic gap for [continuous hot rolling mass production of Φ380–630mm extra-large diameter seamless steel pipes], achieving stable supply of high-quality pipes formed via single-pass rolling.

2. Product Supply Gap: Shortage of Domestically Produced Extra-Large Diameter Pipes for the High-End Energy Sector

1) Large-diameter casing and gathering/transport pipelines for onshore and offshore oil & gas
Previously, large-size, high-grade, corrosion-resistant extra-large casing and subsea pipelines relied on imports or hot-expanded substitutes; the continuously rolled finished pipes meet rigorous API standards, supporting the localization of oil and gas pipeline networks and deep-sea projects.

2) Piping systems and thick-walled pressure vessel piping for supercritical and ultra-supercritical high-pressure boilers
Addresses the domestic production shortfall for large-diameter heat-resistant steel (P91/P92) continuous-rolled pipes and reduces boiler manufacturers’ reliance on imports for extra-large piping.

3) Extra-large structural pipes for new energy equipment, large-scale coal chemical projects, and heavy engineering machinery
Ensures a stable supply of extra-large diameter seamless pipes for applications such as wind power, hydrogen storage and transport, large hydraulic cylinders, and crane booms.

3. Filling a gap in the industrial landscape: Breaking the technological barriers held by overseas enterprises in extra-large, high-end seamless pipes

Previously, there was a global scarcity of large-diameter, high-quality continuous-rolled seamless pipes, with the market for high-end, extra-large specifications long dominated by European and Japanese manufacturers;
Upon completion of this production line, China possesses the world’s largest-diameter continuous-rolling seamless steel pipe line with independent production capabilities, enabling competitive large-scale exports and reshaping the international supply landscape.

4. Filling the gap in continuous size ranges

The previous upper limit for continuous rolling was Φ380mm; the new unit extends this capability up to Φ630mm.
This establishes a comprehensive hot-rolled seamless steel pipe product portfolio ranging from Φ24mm to Φ630mm, creating a production base with the world’s most extensive range of single-unit specifications; this addresses both the company’s own limitations and the domestic industry’s shortage regarding the continuous supply of extra-large specifications.