Sihe Steel
Sihe Steel
Explore our premium industrial-grade stainless steel products designed for high pressure, thermal cycling, and corrosion resistance.
Liaocheng Sihe Stainless Steel Material LTD is a world-class manufacturing authority specializing in the design, cold-drawing, and precise finishing of high-performance stainless steel coiled tubing, polishing tubes, and seamless instrumentation piping. Driven by ten years of continuous metallurgy research, we operate three advanced coiled tubing production lines alongside three structural line operations—delivering superior solutions that rigorously conform to GB, ASTM, ASME, JIS, and EN standards.
We pride ourselves on dual-certified materials including 304/304L, 316/316L, 321, 317L, 309S, 310S, and high-performance super-alloys such as Duplex 2205, Super Duplex 2507, Incoloy 800/825, and Inconel 625. Utilizing state-of-the-art online bright annealing technologies, we neutralize internal stresses to achieve optimal ductility, making our tubing the premier selection for demanding subsea umbilical systems, downhole hydraulic lines, and chemical processing facilities globally.
Currently shipping to over 30 countries and regions, including Germany, the United States, Spain, South America, Southeast Asia, the Middle East, and Eastern Europe.
Outer diameters from 0.125" (3.175mm) to 1" (25.4mm), with wall thicknesses up to 0.165" (3mm). Continuous splice-free lengths up to 32,800 feet (10,000 meters).
For procurement professionals, EPC (Engineering, Procurement, and Construction) firms, and material engineers, sourcing 316 and 316L stainless steel tubing is a balance of metallurgy, compliance, and supply chain reliability. The addition of Molybdenum (2.0-3.0%) in 316 alloys elevates resistance to chloride-induced pitting and crevice corrosion compared to basic chromium-nickel alloys like 304.
Deepwater offshore environments require extremely long lengths of tubing to transport hydraulic fluids, chemicals, and electrical power. Traditional welded joints are failure vectors due to intergranular corrosion. Our splice-free coiled tubes up to 10,000 meters minimize orbital welding, lowering maintenance and pressure failure risks.
For sour gas processing environments, steel components must resist sulfide stress cracking (SSC). Liaocheng Sihe manufactures 316/316L tubing adhering to ISO 15156/NACE MR0175, ensuring long-term safety under high H2S concentrations.
Ultra-high purity (UHP) gas delivery lines in modern semiconductor fabs require low outgassing and high inner-surface smoothness. Our bright annealed and polished tubing meets these standards, preventing particulate contamination.
Understanding chemical variance is vital for selecting the correct material. Grade 316L features a lower carbon limit (max 0.03%), which prevents chromium carbide precipitation during welding and avoids sensitization. Below is the chemical profile comparison under standard ASTM A269/A213 specifications:
| Element (%) | Grade 316 (UNS S31600) | Grade 316L (UNS S31603) | Technical Impact & Engineering Advantage |
|---|---|---|---|
| Carbon (C) | 0.08 max | 0.03 max | Low carbon prevents sensitization and intergranular corrosion during welding. |
| Manganese (Mn) | 2.00 max | 2.00 max | Assists in deoxidation and increases tensile strength/surface hardness. |
| Chromium (Cr) | 16.0 - 18.0 | 16.0 - 18.0 | Forms a self-healing passive chromium-oxide layer for corrosion resistance. |
| Nickel (Ni) | 10.0 - 14.0 | 10.0 - 14.0 | Stabilizes austenitic structure, improving ductility and low-temp toughness. |
| Molybdenum (Mo) | 2.00 - 3.00 | 2.00 - 3.00 | Substantially increases resistance to pitting and crevice corrosion in chloride solutions. |
| Silicon (Si) | 0.75 max | 0.75 max | Improves oxidation resistance in high-temperature atmospheres. |
Our facility uses advanced inline bright annealing technology. Heat treating austenitic stainless steel tubes at temperatures ranging from 1040°C to 1150°C in a controlled hydrogen/nitrogen atmosphere prevents scale formation and oxidation. This step recrystallizes the cold-worked grain structure, reducing hardness and improving ductility for easier bending and flanging.
Every batch of 316/316L coiled tubing undergoes a comprehensive quality verification protocol to ensure long-term performance in aggressive environments:
We provide value-added, customized processing options to deliver install-ready solutions that reduce setup times for on-site operations:
Supporting tight bending and precision helical wrapping configurations optimized for heat exchangers, condensers, and micro-reactors.
Engineered flanging for quick-connect chemical couplings and automotive exhaust integrations, ensuring leak-tight seal geometries.
Laser-guided precision cutting to custom lengths with deburred end-prep finishes to protect system integrity during installation.
Tailored mechanical and electro-polishing treatments to meet critical sanitary requirements in pharmaceutical and high-purity gas lines.
Liaocheng Sihe stainless steel tubing provides specialized corrosion protection, thermal efficiency, and pressure containment across a wide range of industries:
High thermal conductivity, minimal scale formation, and superior pressure containment under continuous thermal cycling conditions.
Optimized for refrigeration lines handling high operating pressures and temperature swings without structural fatigue.
Superior resistance to sulfuric, phosphoric, and organic acids, preventing product contamination and system leaks.
Polished contact surfaces that resist organic growth, maintain sanitary standards, and clean easily.
Smooth internal surfaces (EP treatment) designed to prevent active ingredient adhesion in sterile process environments.
Designed for high thermal and mechanical stress profiles in superheaters, boilers, and recovery lines.
Built to withstand sour gas corrosion, thermal cracking, and chloride exposure in subsea systems.
High strength-to-weight ratio and fatigue resistance, optimized for fuel injection systems and hydraulic control lines.
Liaocheng Sihe maintains a strict quality management system (QMS) verified by leading global classification societies. Our products meet international performance standards, ensuring compliance for chemical plants, offshore platforms, and aviation programs:
Our mill manufactures products to order under the following specifications:
Technical answers to common questions about purchasing, metallurgy, and delivery schedules from our factory:
We manufacture a wide range of specialized stainless steel profiles, including heat exchanger tubes and high-purity capillary pipes:
Duplex and austenitic seamless coils (e.g., 2205, 316L) designed for high-pressure control lines and marine environments.
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Standard sizes, including 1/2" OD, designed for chemical transfer systems and industrial processing equipment.
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High-temperature oxidation-resistant 310/310S grade coiled tubes, optimized for heat exchangers and furnace components.
Explore CategoryExplore our wider range of welded exhaust lines, heat exchanger piping, and specialty alloy tubes:
A look inside Liaocheng Sihe's operations, highlighting our clean-room finishing stages and automated cold-drawing lines:
In modern industrial systems, engineers frequently specify dual-certified 316/316L stainless steel. This certification guarantees that the material meets both the low-carbon limits of 316L (maximum 0.030% carbon) for corrosion resistance, and the higher mechanical strength requirements of standard 316. Our manufacturing process maintains this balance, ensuring our tubes offer excellent performance under high pressure.
The addition of 2-3% Molybdenum increases resistance to chloride pitting, which is measured by the Pitting Resistance Equivalent Number (PREN). For 316/316L, the PREN ranges from 23 to 25, compared to 18 for standard 304, making it suitable for marine environments.
Austenitic stainless steels can experience chloride stress corrosion cracking (SCC) at temperatures above 60°C. For these conditions, we offer alternative high-performance options, including Duplex 2205 and Incoloy 825, to ensure long-term stability.
We ensure full material traceability back to the original melt batch. Heat numbers are stamped on our products, allowing engineers to verify the chemical makeup and physical test results of every delivery.
