Sihe Steel
Sihe Steel
Explore our high-tolerance, corrosion-resistant austenitic, duplex, and nickel alloy tubing solutions.
Corrosion resistant, highly accurate dimensional tolerances for instrumentation networks.
High tensile strength and excellent pitting resistance in marine settings.
Low carbon modification preventing intergranular corrosion during orbital welding.
Super-long coiled tubing for downhole control valves and chemical injection lines.
Precision drawn ultra-fine tubes for chromatography and medical devices.
Specialized outer diameter (1/8 inch) designed for hydraulic systems.
Highly polished biocompatible micro-tubing suited for medical needle and catheter arrays.
Heat-resistant ferritic stainless steel offering high thermal fatigue resistance.
Within the modern metallurgy and fluid control sectors, 316 stainless steel capillary tubing represents the baseline for high-precision, corrosion-resistant transfer lines. Characterized by outer diameters typically below 6mm (0.25 inches) and engineered with high wall-thickness-to-diameter ratios, capillary tubes are vital in instrumentation, chromatography, chemical dosing, and geothermal systems.
Unlike standard utility piping, capillary tubing demands rigorous control over inner surface roughness ($Ra < 0.4\,\mu\text{m}$), concentricity, and metallurgical uniformity. The global market is divided into high-tolerance application spaces including offshore subsea control systems (umbilicals), medical micro-fluidic channels, aerospace hydraulic conduits, and high-performance liquid chromatography (HPLC) units.
Due to the addition of 2-3% Molybdenum (Mo), Type 316/316L offers vastly superior resistance to chloride-induced pitting and crevice corrosion compared to basic nickel-chromium alloys like 304. As subsea oil and gas extraction moves into deeper waters and chemical plants run at elevated temperatures, the demand for high-reliability coiled capillary lines has surged, prompting strict alignment with international quality standards including ASTM A269, ASTM A213, EN 10216-5, and NACE MR0175.
Hailing from China’s premier industrial steel manufacturing zone, Liaocheng Sihe Stainless Steel Material LTD operates six advanced production lines designed specifically for thin-walled precision tubing. As a leading exporter and factory, we specialize in high-integrity stainless steel coiled tubes, polishing tubes, and seamless capillary arrays.
We strictly govern our production through rigorous standards including GB, ASTM, ASME, JIS, and EN. Our material catalog extends from structural grades to high-performance super-alloys: 304/304L, 316L, 321, 317L, 309S, 310S, INCOLOY 800, Duplex 2205, Super Duplex 2507, Incoloy 825, and Inconel 625.
Our coiled tubing is available in outer diameters ranging from 0.125 inches (3.175 mm) up to 1 inch (25.4 mm), with wall thicknesses up to 0.165 inches (3.0 mm). To facilitate subsea umbilical manufacturing and minimize weld-joint vulnerabilities, we deliver continuous joint-free lengths of up to 32,800 feet (10,000 meters).
In the highly competitive precision metal sector, Chinese manufacturers have advanced from basic scale producers to global technological pioneers in thin-walled draw processes and online thermal treatments.
Liaocheng Sihe integrates state-of-the-art online bright annealing (OBA) technology. Operating in a controlled, ultra-pure hydrogen environment, this line-integrated softening treatment eliminates oxidation, resulting in a mirror-like interior and exterior surface finish with low residual stress and high ductility.
We reduce field risk by performing systematic, non-destructive testing on every batch. Our factory is equipped with advanced testing systems for 100% pneumatic air-tightness, hydrostatic pressure, microscopic hardness, yield/tensile strength, flattening, and flaring to ensure absolute dependability under extreme environments.
By coupling raw material sourcing with drawing, sizing, and post-processing in one localized area, we bypass mid-chain shipping delays. This ensures standard sample processing within 7 days, and high-volume mass production delivery within 20 to 30 days, supported by complete material test reports (MTRs).
Choosing the correct alloy grade requires matching chemical stability with pressure constraints. Review the composition thresholds and physical parameters of our core precision tubing inventory:
| Alloy Grade | UNS Designation | Major Elements (Cr, Ni, Mo, etc.) | Tensile Strength (MPa) | Yield Strength (MPa) | Primary Industrial Use Case |
|---|---|---|---|---|---|
| 304 / 304L | UNS S30400 / S30403 | 18-20% Cr, 8-10.5% Ni, Max 0.03% C (L) | ≥ 485 | ≥ 170 | Medical instruments, food processing, commercial refrigeration |
| 316 / 316L | UNS S31600 / S31603 | 16-18% Cr, 10-14% Ni, 2-3% Mo, Max 0.03% C (L) | ≥ 485 | ≥ 170 | HPLC chromatography, subsea hydraulic lines, chemical dosing |
| Duplex 2205 | UNS S32205 | 22-23% Cr, 4.5-6.5% Ni, 3-3.5% Mo, 0.14-0.20% N | ≥ 655 | ≥ 450 | Offshore downhole umbilicals, high-pressure marine sensors |
| Inconel 625 | UNS N06625 | 58% Ni, 20-23% Cr, 8-10% Mo, 3.15-4.15% Cb+Ta | ≥ 827 | ≥ 414 | Aerospace propulsion, deepwater geothermal, sour gas wells |
Modern fluid control systems demand more than raw straight tubes. Liaocheng Sihe supports engineering teams by providing ready-to-integrate sub-assemblies through advanced downstream tube fabrication:
From micro-liter pharmaceutical injection systems to high-pressure subsea oil lines, our tubes are designed to withstand challenging environments.
Global procurement teams prioritize supply chain stability and metallurgical traceability. Factors driving change in precision alloy sourcing include:
Modern offshore drilling and deep-sea completions use umbilical control lines that span miles. Every orbital weld-joint introduces a potential point of failure. B2B buyers now seek extra-long seamless spools (exceeding 10,000 meters) to improve system reliability.
Compliance with ASTM A269 and EN 10204 3.1 certification is standard practice in key industries. Providing chemical analyses, mechanical properties, and eddy-current testing results is essential to meet strict risk management standards.
While 316L remains a cost-effective standard, high-temperature and sour-gas wells require high-performance alternatives. Factories must offer flexible production schedules for duplex 2205, Incoloy 825, and Inconel 625 to meet these challenging conditions.
Our quality system is verified by international inspection bodies. Below are our plant operation and testing certificates:
We manufacture a wide range of specialized stainless and nickel alloy tubing to meet different technical requirements.
Duplex 2205 stainless steel combines high yield strength with good pitting and stress corrosion cracking resistance in chloride environments.
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Our 1/2-inch stainless steel coiled tubing offers a good balance between pressure rating and flow area for industrial distribution lines.
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High-temperature oxidation-resistant 310 grade tubing designed for furnaces, kilns, and thermal process environments.
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Designed for subsea control valves requiring smooth internal fluid flow and high resistance to seawater corrosion.
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Optimized for efficient thermal transfer in chemical processing and boiler systems.
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Designed for high-pressure saturated steam lines, reducing scale buildup and steam leaks.
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Micro-bore tubes for pressure gauges, remote sensing systems, and gas chromatography analyzers.
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Resistant to aggressive chemicals, designed for methanol injection in downhole systems.
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High strength-to-weight ratio tubing certified for high vibration and pressure cycles.
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Precision control lines, industrial exhaust piping, and nickel alloy tubing options.
Heat resistant ferritic alloy designed for automotive silencers and exhaust loops.
Welded stainless pipe for structural and decorative applications.
High molybdenum nickel alloy for high pressure and temperature sour gas wells.
Duplex grade tubing offering resistance to pitting and stress-corrosion cracking.
Tight-tolerance drawn tubes suited for machine parts and structural designs.
High-integrity nickel-chromium-molybdenum alloy coiled tubing for chemical processing.
High-precision medical grade capillaries offering consistent inner bore diameters.
Seamless duplex tubing designed to withstand chloride-stress cracking.
