Sihe Steel
Sihe Steel
Explore our flagship configurations engineered to meet the stringent demands of American subsea and industrial projects.
The demand for high-performance stainless steel encapsulated tubing in the United States has experienced dynamic growth, catalyzed by deepwater exploration projects in the Gulf of Mexico, extensive geothermal system developments, and the expansion of the domestic petrochemical sector. Encapsulated tubing—featuring a core metal tube shielded by a robust thermoplastic outer jacket (e.g., PVDF, FEP, PFA, or TPU)—serves as the mechanical and chemical baseline for deep-sea oil extraction, shale gas fracturing, and offshore chemical dosing systems.
American engineering firms enforce stringent specifications, calling for continuous, seamless coil runs exceeding 10,000 meters to minimize subsea joints. The localized application parameters require exceptional resistance to chloride-induced stress corrosion cracking, high hydrostatic pressures, and sour gases (H₂S). As US suppliers strive to balance cost efficiency with reliability, direct partnerships with top-tier international manufacturers who adhere strictly to global regulatory compliance standards (ASTM, ASME, API, and NACE) have become a strategic procurement avenue.
Different industrial processes mandate highly tailored combinations of internal alloys and outer polymer coverings. Below is the technical matrix illustrating the chemistry, resistance profile, and polymer selection criteria utilized across US industrial sectors:
| Alloy Grade | Common US Equivalents | PREN Value | Standard Encapsulation | Typical Applications |
|---|---|---|---|---|
| Austenitic 316L | UNS S31603 | 23–25 | TPU / PVC | Onshore chemical injection lines, hydraulic control lines |
| Duplex 2205 | UNS S31803 / S32205 | 35–37 | FEP / PVDF | Subsea wells, deep oil extraction, marine environments |
| Super Duplex 2507 | UNS S32750 | >40 | PVDF / PFA | HPHT (High Pressure High Temp) offshore oil & gas |
| Incoloy 825 | UNS N08825 | 31–32 | Fluoroelastomer / FEP | High chloride environments, sour oil wells (H₂S) |
| Inconel 625 | UNS N06625 | >45 | PFA / PEEP | Ultra-deepwater exploration, critical subsea safety valves |
We strictly execute operations following ASTM A269, ASTM A213, ASTM A789, and NACE MR0175/ISO 15156. All raw materials undergo spectrometer validation prior to cold drawing.
Our polymers (TPU, PVDF, PFA) protect the internal alloy tubing from salt spray, mechanical abrasion, structural impact, and galvanic corrosion.
Configured up to 32,800 feet (10,000 meters) in length. Eliminating orbital welds on-site dramatically reduces installation risk and system downtime.
Originating from China, Liaocheng Sihe Stainless Steel Material LTD is a world-class manufacturing authority specializing in coiled tubing, bright-annealed polishing lines, and encapsulated control lines. With six high-performance continuous production lines, our products meet GB, ASTM, ASME, JIS, and EN standards. We process standard and exotic metal grades, including 304/304L, 316L, 321, 310S, Duplex 2205, Super Duplex 2507, Incoloy 825, and Inconel 625.
Our commitment to engineering integrity is backed by a state-of-the-art online bright annealing heat treatment system. This allows continuous metallurgical softening to guarantee maximum flexibility and pressure retention in long coiled lines. Currently, 80% of our production volume is exported globally, serving major markets in the United States, Germany, Spain, South America, and the Middle East.
From heavy industry to high-purity medical platforms, our processing divisions handle the most demanding specifications.
We understand that subsea and petrochemical installations require custom configurations. Our services include precision spiral coil forming, tube cutting and straightening, custom outer sheath sizing (OD 0.125" up to 1"), laser/mechanical cutting, flanging, and custom surface electropolishing. Each tube is tested up to 100% of its hardness and tensile parameters to withstand complex bending stresses on offshore reels.
Liaocheng Sihe products are implemented globally across a wide range of industries:
We provide full transparency with EN 10204 3.1 Material Test Reports (MTRs), PMI chemical analysis certifications, pressure testing reports, and ISO quality management approvals.
As deepwater exploration moves into ultra-deep basins (depths exceeding 3,000 meters), operating temperatures and pressures climb exponentially. High-pressure, high-temperature (HPHT) wells require encapsulated control lines that maintain structural integrity in sour oil (high H₂S and CO₂) environments. The technical roadmap of Liaocheng Sihe involves continuous investment in super-alloys (Hastelloy C276, Monel 400) and advanced thermoplastic composites like high-temperature Polyetheretherketone (PEEK) encapsulation.
Additionally, the transition to green energy in the United States highlights hydrogen transportation systems as a key growth sector. Our continuous seamless coiled lines are designed to resist hydrogen embrittlement. They deliver excellent containment for high-pressure hydrogen fueling and carbon capture, utilization, and storage (CCUS) operations.
Navigating global supply chains requires balancing cost, quality compliance, and delivery logistics. For US procurement managers, importing direct from specialized manufacturers in China can reduce material costs by 20% to 35% compared to domestic distributors. This savings does not compromise project engineering criteria.
Liaocheng Sihe streamlines this process by providing comprehensive logistical coordination, standard seaworthy packaging, wooden box reinforcement, and secure custom crating for ocean transit. Our team also manages all customs compliance details, delivering directly to Gulf Coast warehouses or subsea assembly yards in Texas and Louisiana.
Common technical and commercial questions from procurement engineers and project managers in the United States.
Our core product families are categorized to help you quickly identify the best match for your technical applications.
2205 duplex stainless steel containing austenitic and ferritic properties. Engineered to endure high chloride stress corrosion environments.
View More
1/2" stainless steel coiled tubing refers to a continuous coil configuration optimized for deep downhole chemical delivery lines.
View More
High temperature resistant stainless steel tubing suitable for heat exchangers and waste gas exhaust piping systems.
View More
Premium 316L and Alloy 825 control lines for subsea well completions.
High purity ultra-clean inner surface tubes for semiconductor fabrication.
Extra-long seamless capillary runs designed for high-pressure chromatography.
Engineered for high temperature and high pressure subsea oil extraction.
Hastelloy and Super Duplex pipes tailored for corrosive chemical injection.
Robust TPU/PVDF jacket options protecting the underlying metallurgy.
JIS SUS202 welded lines for high durability and performance.
Engineered for high sulfide and high pressure oil operations.
Multiple control and injection lines bundled together for umbilicals.
Engineered for subsea distribution units (SDU) and subsea trees.
Our advanced drawing and sheathing lines operate around the clock to meet global delivery demands.
Explore our wholesale catalog, engineered to meet the requirements of American and international operations.
Whether you require long spools for offshore control lines or customized encapsulation sheathing for chemical injection, our engineering team is here to assist. We offer complete Mill Test Reports (MTRs) and global logistical coordination.
Send Inquiry Now
