Sihe Steel
Sihe Steel
As a leading Chinese expert in manufacturing and processing top-grade stainless steel coiled tubes, polishing tubes, and seamless coiled tubing, we support the backbone of international industrial infrastructure. Armed with six specialized production lines, we adhere meticulously to international directives, ensuring raw material integrity, dimensional tolerance, and advanced microstructure standards.
Our comprehensive production line handles premium steel types including 304/304L, 316L, 321, 317L, 309S, 310S, and INCOLOY 800. For deepwater, high-pressure, and highly corrosive operating environments, we utilize high-alloy profiles: Austenitic 316L, Duplex 2205, Super Duplex 2507, Incoloy 825, and Inconel 625.
By using the world’s leading online bright annealing technology, we supply coiled tubing from an outer diameter of 0.125 inches (3.175 mm) up to 1 inch (25.4 mm), with wall thicknesses up to 0.165 inches (3 mm). Single continuous spool lengths can reach up to 32,800 feet (10,000 meters) without orbital welds, reducing potential leakage pathways in umbilical systems.
In offshore oil extraction and chemical processing plants, minimizing joint connections is critical. Traditional straight pipes require orbital welding every 6 to 12 meters, adding time, labor, and inspectorial costs. Every weld introduces a risk of localized pitting corrosion, hydrogen embrittlement, or stress corrosion cracking (SCC).
Our seamless coiled tubing solves this challenge. Offering continuous lengths up to 10,000 meters allows engineers to implement direct-line deployments for subsea chemical injection lines, hydraulic control lines, and downhole safety valves. This significantly lowers installation downtime, optimizes fluid dynamics, and secures operation integrity under harsh offshore environments.
Liaocheng Sihe Stainless Steel Material LTD integrates raw material validation with structural processing, offering end-to-end quality control to global engineering, procurement, and construction (EPC) contractors.
| Alloy Grade | Outer Diameter (OD) | Wall Thickness (WT) | Max Continuous Length | Primary Standards | Key Application |
|---|---|---|---|---|---|
| 304 / 304L | 0.125" - 1.00" (3.175 - 25.4 mm) | Up to 0.165" (3.0 mm) | 10,000 meters (32,800 ft) | ASTM A269, ASTM A213, EN 10216-5 | Food & Beverage, Cooling, General Hydraulics |
| 316 / 316L | 0.125" - 1.00" (3.175 - 25.4 mm) | Up to 0.165" (3.0 mm) | 10,000 meters (32,800 ft) | ASTM A269, ASTM A213, JIS G3459 | Chemical Processing, Subsea Control Lines, Medical |
| Duplex 2205 | 0.250" - 0.750" (6.35 - 19.05 mm) | Up to 0.120" (3.0 mm) | 6,000 meters (19,685 ft) | ASTM A789, ASTM A790 | Offshore Oil & Gas, High-Chloride Heat Exchangers |
| Super Duplex 2507 | 0.250" - 0.750" (6.35 - 19.05 mm) | Up to 0.120" (3.0 mm) | 5,000 meters (16,400 ft) | ASTM A789, ASTM A790 | Deepwater Umbilicals, Desalination Plants |
| Incoloy 825 / Inconel 625 | 0.125" - 0.750" (3.175 - 19.05 mm) | Up to 0.095" (2.41 mm) | 4,000 meters (13,120 ft) | ASTM B704, ASTM B423 | Extreme Sour Gas Wells, Geothermal Steam Systems |
With hydrocarbons shifting to deeper waters, subsea umbilical systems require higher collapse resistance and corrosion performance. The market is shifting from standard 316L to Super Duplex 2507 and Nickel Alloys to handle increased external pressures and sour gas profiles.
Using oxygen-free, protective atmosphere hydrogen induction heating allows online annealing without forming surface oxides. This eliminates chemical pickling, resulting in a mirror-like finish (polishing grade) that keeps the tube's inner surface smooth and free of contamination.
Hydrogen infrastructure requires materials resistant to hydrogen embrittlement. Austenitic stainless steel coiled pipes, particularly those with higher nickel equivalents (such as 316L/317L or Incoloy 825), provide the mechanical stability needed for high-pressure hydrogen transport lines.
At Liaocheng Sihe Stainless Steel Material LTD, we offer processing options that turn basic coiled tubes into finished, application-ready parts. Our custom processing handles multiple dimensions (outer diameter 6.35mm to 19mm) and grades (304, 316L, 2205) to ensure reliable performance under high pressure.
To ensure our products withstand the demanding pressures of industrial use, our quality control team performs comprehensive testing on every batch:
Verifying target mechanical properties and grain size uniformity.
Hydrostatic test pressures up to 100 MPa (14,500 psi) to ensure seal integrity.
Assessing ductility and preventing weld cracking during end-forming.
Electromagnetic testing of the entire spool length to spot subsurface anomalies.
