Sihe Steel
Sihe Steel
In modern industrial infrastructure, fluid transportation, heat exchange processes, and control lines operating under harsh conditions require structural integrity of the highest level. Liaocheng Sihe Stainless Steel Material LTD is a Chinese precision seamless stainless steel tube manufacturer. We engineer seamless coiled tubing, capillary tubing, and specialized heat exchanger pipes designed to withstand corrosive and high-pressure environments globally.
Operating six state-of-the-art production lines and three specialized coil tube lines, we maintain production control from raw material selection to structural testing. All tubes conform to major international specifications including ASTM, ASME, GB, JIS, and EN. Our manufacturing catalog features austenitic steel grades such as 304/304L, 316L, 321, 317L, 309S, 310S, duplex alloys like Duplex 2205 and Super Duplex 2507, and nickel superalloys including Incoloy 800, Incoloy 825, and Inconel 625.
As offshore exploration advances into deep water, control systems are subjected to severe external pressures, chemical corrosion, and mechanical stress. Our long-length seamless coiled tubing (up to 32,800 feet / 10,000 meters in a single continuous reel) eliminates the structural weakness introduced by orbital field welds.
By implementing advanced inline bright annealing technology, we heat-treat tubes in a controlled hydrogen atmosphere. This process maintains a scale-free inner diameter (ID) and outer diameter (OD), optimizing hydraulic flow rates and preventing fluid contamination in analytical instrumentation and subsea umbilicals.
Selecting the correct alloy is essential for long-term operational integrity and corrosion prevention. Below is an engineering guide detailing the key material grades utilized in our seamless stainless steel tube manufacturing process, designed to match mechanical demands with corrosion-resistance profiles.
| Material Class | Grade Designation | Key Chemical/Structural Composition | Primary Industrial Applications |
|---|---|---|---|
| Austenitic Steel | 304 / 304L | 18% Cr - 8% Ni; Low Carbon variation prevents carbide precipitation. | HVAC, food and beverage processing, utility pipelines, domestic systems. |
| Austenitic Steel (Marine) | 316L | 16-18% Cr - 10-14% Ni - 2-3% Mo; High Molybdenum prevents pitting. | Chemical dosing, subsea umbilical tubes, marine instrumentation, pharmaceuticals. |
| Duplex Stainless Steel | Duplex 2205 / UNS S31803 | 22% Cr - 5% Ni - 3% Mo - 0.18% N; Dual-phase austenite-ferrite structure. | Offshore exploration, high-pressure subsea control lines, chemical processing plants. |
| Super Duplex Steel | Super Duplex 2507 / UNS S32750 | 25% Cr - 7% Ni - 4% Mo - 0.27% N; High PREN (>42) rating. | Deepwater oil production, reverse osmosis desalination, acids processing. |
| High Temp Alloy | 310S / INCOLOY 800 | High Nickel and Chromium; oxidation and carburization resistant. | Boilers, heat exchangers, petrochemical furnaces, thermal processing units. |
| Nickel Superalloy | Incoloy 825 / Inconel 625 | Ni-Cr-Mo matrix with added Niobium/Iron; high chloride crack immunity. | Sour gas (H2S) service, geothermal wells, nuclear reactors, aerospace exhaust. |
Global engineering projects require raw material processing and predictable delivery schedules. Operating from Liaocheng, China's steel tubing hub, Liaocheng Sihe Stainless Steel Material LTD integrates regional supply chains to deliver metallurgical quality and cost efficiency. Our production framework provides major benefits to global procurers:
We source raw billet stock from premium domestic and international steel mills. This direct sourcing ensures uniform chemical composition, preventing grain boundary precipitation and ensuring reliable mechanical forming and bending.
Our online bright annealing facilities allow continuous heat treatment under a high-purity hydrogen shielding gas. This process retains a clean, oxide-free surface, avoiding the surface defects associated with acid pickling methods.
With six dedicated production lines running, we can scale operations rapidly. This setup allows us to balance the manufacturing demands of large-scale oil and gas projects with smaller custom orders, managing lead times effectively.
We carry out complete testing protocols on every production run. This quality assurance framework confirms the structural integrity of our tubes under pressure:
Industrial buyers must manage risks related to material specification changes, customs clearance delays, and inconsistent physical properties. We structure our international sales and support teams to address these procurement concerns directly.
We provide full Mill Test Certificates (MTCs) to EN 10204 3.1, along with raw material heat numbers, chemical composition analyses, and physical property test results.
We manufacture custom tube profiles outside standard sizes, from micro-bore capillary systems (0.125” OD) to heavy-wall heat exchanger tubes (up to 1” OD).
Tubes are packaged on custom steel reels or within wooden crates with structural end caps, protecting them from physical damage and salt air corrosion during transit.
We support multiple delivery terms, including FOB, CIF, DDP, and Ex-Works, coordinating with international freight networks to streamline port clearance and overland shipping.
Precision tubing is used in critical applications across many industrial sectors. Our seamless stainless steel tubes perform reliably under elevated pressures, extreme temperatures, and in corrosive environments.
Our ASTM A213 seamless tubes provide reliable thermal conductivity and pressure containment in high-temperature boiler systems.
Continuous coiled tubing prevents refrigerant leaks in evaporator and condenser units, improving system efficiency.
High-alloy grades resist corrosion from aggressive acids and alkaline compounds in transport pipelines.
Smooth inside surfaces prevent bacterial accumulation, meeting sanitary processing requirements.
Precision capillary tubes deliver high-purity fluid transportation required in bioreactors and laboratories.
Our high-pressure tubing lines support steam generation, superheaters, and cooling systems in traditional and nuclear plants.
Duplex and nickel superalloy tubes perform under severe mechanical stress and sour gas conditions.
High-strength capillary tubes and flanged lines are used in hydraulic actuator circuits and high-vibration engine environments.
Liaocheng Sihe provides post-drawing services, supplying semi-finished and finished tubing components directly to assembly lines:
We process coils to specified center-line diameters and spiral configurations, matching system dimensions for compact heat exchangers and condensers.
For applications needing straight lengths over coiled forms, our straightening lines achieve close dimensional tolerances, while laser cutting ensures clean, burr-free tube ends.
We form tube ends with structural flanges and flares to interface with automotive exhaust connections, hydraulic blocks, and high-pressure chemical fittings.
We maintain quality control procedures throughout the manufacturing process, ensuring our materials meet international standards for reliability in high-stakes projects.
Technical details, sourcing rules, and compliance standards for global buyers sourcing seamless steel tubing from China.
Liaocheng Sihe Stainless Steel Material LTD processes seamless tubes to support global project requirements. The details below outline our standard sizing, forming capabilities, and material choices.
Specifically engineered for subsea umbilicals and chemical injection lines, our 2205 duplex and 316L coiled tubing is supplied in continuous spools, reducing the risk of joint failures.
Our 1/2" OD stainless steel coiled tubing is cold-drawn and bright-annealed to support high pressures in control panel operations, hydraulic loops, and chemical dosing systems.
Designed for thermal processing applications, our 310S stainless steel coiled tubing provides oxidation resistance in high-temperature environments.
Custom orbital winding ensures tension control during packing, preventing deformation in transit.
Cold drawing achieves close dimensional tolerances and a clean interior surface finish.
Atmosphere-controlled heat treatment restores ductility without oxidation, producing a clean, dry surface.
Physical properties are verified via tensile, flattening, and flaring tests on each batch.
Duplex alloys undergo phase-ratio checks to confirm the 50/50 austenite-ferrite structure balance.
Tubes are pressure tested to verify mechanical strength and structural integrity.
Laser micrometers verify OD and wall thickness parameters throughout the production cycle.
Tubes are packaged on custom steel or wooden reels for protection during international transport.
Our team coordinates port delivery and customs documentation to streamline international shipments.
Tubes are marked with heat numbers to maintain traceability from raw billet to finished spool.
Our production facilities support global supply chains for seamless stainless steel tubing.