Explore our primary export-grade forged flanges manufactured to extreme pressure, mechanical, and anti-corrosive standards.
How Chinese forging hubs drive safety, standardisation, and mechanical integrity in critical global fluid dynamics.
Steel pipe flanges are fundamental structural components connecting pipes, valves, pumps, and pressure vessels across high-consequence industries. Driven by global investments in midstream oil and gas transport, liquefied natural gas (LNG) export terminals, offshore wind platform foundations, nuclear cooling circuits, and green hydrogen transmission networks, the demand for pressure-rated forged steel flanges continues to scale exponentially. Global Engineering, Procurement, and Construction (EPC) firms require absolute metallurgical consistency, complete material traceability, and adherence to international dimensional standards to mitigate catastrophic field failure risks.
China has solidified its position as the premier manufacturing powerhouse for forged steel flanges, with Dingxiang County in Shanxi Province globally recognized as the "Hometown of Forging in China." Anchored in abundant high-grade raw carbon steel billet resources, state-of-the-art ring-rolling machinery, specialized heat-treatment facilities, and deep industrial expertise, Dingxiang produces over one-third of China's exported forged flanges. Shanxi Yuxin Casting & Forging Co., Ltd. sits at the operational core of this ecosystem, leveraging 33 years of continuous direct factory engineering to deliver high-yield forging solutions that outperform traditional cast alternatives.
Forging subjects heated steel billets to extreme mechanical pressures, refining grain structures, enhancing tensile strength, eliminating internal porosity, and improving directional fatigue resistance. In pressure-critical applications operating under cyclic thermal loads or severe vibration (such as high-pressure steam lines or sour gas pipelines), cast flanges present unacceptable risks of micro-cracking and brittle failure. YUXIN's closed-die and ring-rolled forged flanges deliver superior yield strengths (up to 355 MPa for structural carbon steel and higher for custom low-alloy grades) and impact toughness tested down to -40 °C.
Full-spectrum direct control from raw ingot heating to final CNC machining and EN 10204 3.1 certification.
Shanxi Yuxin operates under an audited quality management system assessed by TÜV CERT, meeting strict European Pressure Equipment Directive (PED 2014/68/EU) standards, AD 2000-Merkblatt W0 / TRD 100 qualifications, and ISO 9001:2015. Every batch of carbon, alloy, and stainless steel flanges undergoes documented non-destructive testing (NDT) to guarantee zero-defect shipment.
Spanning an annual manufacturing footprint of 10,000 metric tons of finished flanges and 2,000 tons of specialized forged parts, our facility houses automated ring-rolling machines, heavy hydraulic forging presses, computer-controlled heat treatment furnaces (normalizing, annealing, quenching, tempering), and multi-axis CNC lathes capable of machining dimensions up to 3,000 mm (120 inches).
Every single flange produced in our Dingxiang plant is heat-stamped with a unique heat code directly linked to the chemical ladle analysis and mechanical property test record. We issue 100% compliant EN 10204 3.1 Material Test Certificates (MTCs) as standard, with EN 10204 3.2 third-party witness inspection (Lloyd's Register, TÜV, DNV, SGS) provided upon request.
Technical overview of international flange geometries, pressure ratings, and metallurgical chemistry options available from YUXIN.
| Flange Standard | Nominal Size Range | Pressure Classes / Ratings | Facing Types | Primary Material Grades |
|---|---|---|---|---|
| ASME B16.5 | ½" to 24" (DN15 - DN600) | Class 150, 300, 400, 600, 900, 1500, 2500 | RF, FF, RTJ, T&G, M&F | ASTM A105, A350 LF2, A182 F304/316L, A182 F11/F22 |
| ASME B16.47 (Ser. A/B) | 26" to 60" (DN650 - DN1500) | Class 75, 150, 300, 400, 600, 900 | Raised Face (RF), Ring Type Joint (RTJ) | ASTM A105, A350 LF2, High-Yield A694 F52/F60/F65 |
| EN 1092-1 | DN10 to DN3000 | PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100 | Type A (Flat), Type B1/B2 (RF), Type C/D, Type E/F | P245GH, P250GH, P280GH, S235JR, 1.4301, 1.4404 |
| DIN Standards | DN10 to DN2000 | ND6 to ND160 | Form C, Form D, Form E, Form F, Form N | St37.2, C22.8, 15Mo3, 13CrMo44, 1.4571 (316Ti) |
| JIS B2220 / GOST | 10A to 1500A / DN15-DN1200 | 5K, 10K, 16K, 20K, 30K / PN6-PN100 | RF, FF, Male-Female Concave | SS400, SF440A, GOST 20, 09G2S, 12X18H10T |
Designed with a long tapered hub that transitions stress smoothly into the attached pipe wall. Best for extreme pressure conditions, sub-zero cryogenic fluids, cyclic thermal stresses, and joints subject to 100% volumetric radiographic inspection.
Features a bore slightly larger than the pipe's outside diameter. The pipe slips inside the flange body before fillet welding on both inner and outer sides. Highly cost-effective and easy to align during field installation.
Solid forged dished discs used to seal off pipeline terminations, pressure vessel nozzles, or isolation valves. Subjected to higher internal shear stress than any other flange type under working hydro-pressure.
Includes a recessed socket to seat small-diameter pipe (typically ½" to 4"). A single bottom fillet weld completes the connection. ideal for high-pressure hydraulic, chemical, and steam distribution utility lines.
Used in conjunction with a loose backing flange and a welded stub end. Allows easy bolt hole alignment during maintenance; widely specified in stainless steel system designs to lower material costs.
Heavy-section forged discs and rings precision CNC-drilled for shell-and-tube heat exchangers, boilers, and vessel baffles. Manufactured to tight TEMA standards with dynamic hole pitch measurement.
Tailored steel flange solutions engineered for the world's most demanding operational environments.
Challenge: Wellhead piping and manifold systems operating in sour environments suffer severe Hydrogen-Induced Cracking (HIC) and Sulfide Stress Corrosion Cracking (SSCC).
YUXIN Solution: We forge high-yield carbon steel flanges (ASTM A105 / A350 LF2 / A694 F65) strictly compliant with NACE MR0175/ISO 15156 standards. Combined with specialized RTJ (Ring Type Joint) grooves and metallic ring gaskets, our flanges maintain hermetic pressure containment up to Class 2500 under harsh sour fluid exposures.
Challenge: Thermal expansion, creep strain, and oxidation in supercritical boiler headers and hydrocracking units operating above 500 °C.
YUXIN Solution: Low-alloy chrome-moly steel flanges (ASTM A182 F11 Class 2, F22 Class 3, and F91). Utilizing controlled normalizing and tempering heat-treatment cycles, YUXIN guarantees elevated temperature tensile values and creep rupture strength certified per EN 10204 3.1.
Challenge: Liquefied Natural Gas pipelines at -162 °C risk sudden brittle fracture if steel loses impact ductility.
YUXIN Solution: Fully normalized ASTM A350 LF2 Class 1/2 carbon steel flanges and solution-annealed ASTM A182 F316/316L stainless steel flanges. Impact toughness tested in-house down to -46 °C and -196 °C, delivering minimum Charpy V-notch energy absorbency meeting strict marine transport regulations.
Challenge: Marine splash-zone corrosion and heavy structural wave dynamic fatigue on monopile and jacket platform flange joints.
YUXIN Solution: Heavy-section ring-rolled flanges and custom expansion joint flanges up to 3,000 mm diameter with high-build 3-layer epoxy or 3LPE anti-corrosion coatings. Designed to meet DNV-GL marine classification rules for 30-year design life.
Seamless compliance with regional regulatory standards and regional delivery requirements across five continents.
Fully compliant with the Pressure Equipment Directive (PED 2014/68/EU) and UKCA rules. Materials conform to EN 1092-1, DIN standard dimensions, and AD 2000-W0 specification sheets, ensuring immediate approval by notified bodies such as TÜV, Bureau Veritas, and DNV.
Manufactured strictly according to ASME B16.5, ASME B16.47, and MSS SP-43 specifications. Available with Canadian Registration Numbers (CRN) across all provinces for immediate integration into pressure piping projects in Alberta, Texas, and the Gulf Coast.
Custom forged flanges pre-vetted against stringent NOC vendor requirements (Aramco, ADNOC, KOC). Supported by full sour service metallurgical documentation, HIC/SSCC laboratory test reports, and positive material identification (PMI) logs.
How Shanxi Yuxin verifies structural integrity, surface tolerance, and chemical purity at every phase.
Optical Emission Spectrometry (OES) analysis performed on incoming steel billets and finished flange hubs to ensure strict carbon equivalent (CEQ) control for optimal weldability.
100% volumetric Ultrasonic Testing per ASTM A388 / EN 10228 to detect internal inclusions, micro-cracks, or laminations prior to final machining operations.
Machined flange facing serrations (125–250 µin AARH stock finish), bolt circle diameters, and hub bevels checked with 3D coordinate measuring arms to within sub-millimeter precision.
Brinell and Rockwell hardness profiling across heat-affected zones, alongside destructive tensile, impact, and hydro-testing verification per batch lot.
Pioneering smart forging technologies, green metallurgy, and hydrogen-ready pipeline connections.
As the global energy transition accelerates, YUXIN is at the forefront of forging low-alloy steel flanges engineered to eliminate hydrogen embrittlement. Through ultra-low sulfur raw steel chemistry and controlled grain refinement, our next-generation flanges are certified for 100% pure hydrogen transmission lines at pressures up to 100 bar.
We are integrating real-time laser measurement systems and AI-controlled closed-loop feedback onto our heavy ring-rolling lines. This technology monitors wall thickness, diameter expansion, and forging temperatures dynamically, resulting in enhanced dimensional stability and reduced raw material waste.
By upgrading to energy-efficient electrical induction heating furnaces and utilizing solar energy across our Dingxiang manufacturing facility, Shanxi Yuxin is significantly lowering the embodied carbon footprint of our steel flanges—helping global EPC clients meet Scope 3 emissions reduction targets.
Detailed answers to critical technical questions asked by piping engineers, project buyers, and stockists.
Discover more standard and engineered flange variants manufactured in our Dingxiang plant.
Supplying world-class energy engineering projects and global steel distribution networks for over three decades.
Send us your piping schedules, RFQ items, or custom forging drawings. Our senior metallurgists and export engineers provide actionable technical quotes within 24 hours.
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