Sihe Steel
Sihe Steel
Premium solutions designed for extreme durability, corrosion resistance, and heat transfer efficiency
A Global Leader in High-Grade Coiled Tubing & Specialized Heat-Resistant Pipes
For over a decade, Liaocheng Sihe Stainless Steel Material LTD has established itself at the forefront of China’s metallurgical innovation. Operational with three specialized coil production lines and a total of six high-efficiency pipe extrusion and finishing lines, we manufacture high-performance stainless steel coiled tubes, polishing tubes, and seamless coiled tubing designed for high-temperature and extreme-pressure environments.
Our commitment is strictly governed by globally accepted manufacturing methodologies. We process materials under stringent specifications matching international frameworks including GB, ASTM, ASME, JIS, and EN. We specialize in producing custom lengths up to 32,800 feet (10,000 meters) in seamless runs, significantly reducing the requirement for orbital welding in subsea and chemical process installations.
Continuous draw and bright annealing system at Liaocheng Sihe Facility.
Deciphering the chemical composition and microstructural stability that makes Grade 310/310S the industry benchmark for high-temperature service.
Grade 310 stainless steel contains a high proportion of chromium (24% to 26%) and nickel (19% to 22%). This combination produces a resilient, self-healing chromium oxide layer that prevents further thermal oxidation under continuous use up to 1150°C, and under cyclic heating up to 1040°C.
Exposure of austenitic steels to temperatures between 600°C and 900°C can prompt the precipitation of the brittle sigma phase. Through precision formulation of stabilizing alloys and tight carbon controls, Liaocheng Sihe ensures the long-term structural integrity of our 310S (low-carbon) pipes.
In petrochemical processing plants, reducing atmospheres containing sulfur or carbon can degrade lower-alloy steels. The high nickel content in Grade 310 prevents absorption of carbon, maintaining ductility and resisting thermal fatigue in modern cracker furnaces and gasifiers.
While 316L is widely specified for its marine acid resistance, it fails to maintain structural capacity above 800°C. 309S provides service up to 1000°C but lacks the mechanical stability of 310S under thermal cycling. The incorporation of 20% nickel in 310S guarantees a stable FCC (face-centered cubic) crystal structure, preventing volume expansion and micro-cracking under intense cyclic loads.
Liaocheng Sihe integrates advanced process control with end-to-end testing systems. Our facility employs online gas-shielded bright annealing loops, allowing continuous heat treatment under high-purity hydrogen gas. This prevents internal scaling, maintains low roughness (Ra < 0.4 µm), and removes mechanical stress, yielding pipes that are highly formable for complex configurations.
Our testing array leaves no margin for error. We execute rigorous mechanical tests online and offline: flaring, compression, bend tests, hardness tests, tensile testing, and eddy current detection. This ensures every millimeter of export tubing meets the precise safety parameters demanded by aerospace, petrochemical, and deepwater umbilical networks.
As global oil and gas extraction moves into deeper waters, subsea systems are exposed to increased external hydrostatic pressures and chemical corrosives. Steel tubes utilized within subsea umbilical lines must withstand continuous tensile stresses while preventing hydrogen embrittlement and chloride-induced pitting.
Liaocheng Sihe works alongside marine contractors, providing custom-extruded continuous super-alloys (Inconel 625, Incoloy 825, Duplex 2205). By minimizing mechanical joints and offering smooth inner bores, our coils minimize turbulent flow, optimize hydraulic pressure transmission, and extend the operating life of subsea infrastructure.
We supply specialized coiled tubing conforming to the following parameters:
| Parameter | Imperial Size | Metric Equivalent |
|---|---|---|
| Outer Diameter (OD) | 0.125 in to 1.00 in | 3.175 mm to 25.4 mm |
| Wall Thickness (WT) | Up to 0.165 in | Up to 3.00 mm |
| Coil Length | Up to 32,800 ft | Up to 10,000 meters |
Our downstream metal fabrication and engineering services deliver ready-to-assemble systems for complex applications.
Tailoring material combinations (304, 316L, 2205) and structural designs with diameters ranging from 6.35mm to 19mm for heat-transfer coils.
Precision bending, spiral wrapping, and close-tolerance continuous drawing designed for boilers, chillers, and HVAC heat exchangers.
Laser cutting, high-speed rotary mechanical cutting, and flame-based straightening to achieve close dimensional tolerances.
Mechanical polishing, acid pickling, and gas-purged electro-polishing (EP) to reduce surface friction and chemical residue buildup.
Cold flanging and end-forming processes, commonly specified for automotive exhaust systems and petrochemical instrumentation lines.
Providing components for high-risk, high-specification operations across a wide range of industries.
Liaocheng Sihe has exported products to over 30 countries and administrative territories. Our major markets include the United States, Germany, Spain, South America, Southeast Asia, the Middle East, and Eastern Europe. With a high-speed logistical network operating near major industrial shipping hubs, we ensure reliable delivery timelines for both customized, long-run mill orders and standard bulk product shipments.
To safeguard tubing during international transport, we pack coils using heavy-duty export crates, spooled steel drums, or temperature-regulated shipping containers, preventing mechanical distortion, moisture exposure, or environmental contamination.
Featured components engineered for oilfield services, HVAC, chemical instrumentation, and subsea structures.
2205 stainless steel is a duplex alloy containing austenitic and ferritic microstructures, designed to resist stress corrosion cracking and pitting.
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1/2-inch stainless steel coiled tubing is specified for hydraulic control loops, heat-tracing lines, and chemical injection systems.
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Liaocheng Sihe is a leading manufacturer of high-alloy 310/310S heat-resistant coiled tubing, designed for high-temperature service.
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Liaocheng Sihe is certified for safety, chemical accuracy, and structural integrity across international markets.
Technical guidance, commercial policies, and procurement parameters for international buyers.
Our prices are subject to change depending on supply, raw material cost fluctuations (LME Nickel/Chromium values), and other market factors. We will send you an updated price list after your company contacts us for further detailed information.
Yes, we require all international orders to have an ongoing minimum order quantity. For specific alloys like 310S or Inconel 625, the MOQ depends on diameter and wall thickness. If you are looking to resell or procure smaller quantities, please contact our team to check our current inventory.
Yes, we can provide the majority of requested documentation, including EN 10204 3.1 Material Test Certificates (MTRs), Certificates of Analysis / Conformance, Insurance documents, Certificates of Origin, and standard export documentation as required by global customs.
For custom samples, the lead time is approximately 7 days. For mass production of standard orders, the lead time is 20–30 days after receiving the deposit payment. Lead times become effective when we receive your deposit and final product approval. If our schedules do not align with your project deadline, please discuss this with your sales representative, and we will work to accommodate your schedule.
You can make payments directly to our bank account, via Western Union, or PayPal. Our standard commercial terms are a 30% deposit in advance, with the remaining 70% balance payable against the copy of the Bill of Lading (B/L).
We warranty both our materials and workmanship. Our priority is to ensure your satisfaction with our products. Regardless of warranty status, it is our company policy to address and resolve all customer issues to mutual satisfaction.
Yes, we use high-quality export packaging. We also employ specialized hazard packaging for hazardous materials and certified cold storage shipping for temperature-sensitive items. Custom or non-standard packaging requirements may incur an additional charge.
Shipping costs depend on the delivery method you choose. Express shipping is the fastest but most expensive, while sea freight is generally the most economical solution for bulk orders. Exact freight rates can be provided once we receive details regarding order size, weight, and delivery method.
Explore our targeted product range below, including high-heat and corrosion-resistant alloys
