Explore our export-grade forged steel flanges manufactured at Shanxi Yuxin Casting & Forging plant with 100% heat traceability and precision CNC serration finish.
A authoritative analysis of sealing dynamics, stress distribution, and mechanical behavior under extreme pipeline loading.
Raised Face (RF) flanges represent the most widely utilized connection geometry in international process piping systems today. Designated as Type B under European standard EN 1092-1 and standard facing in ASME B16.5 and ASME B16.47, the design feature concentrates bolt tension directly onto a small raised lip raised above the bolting circle plane. This concentrated force effectively compresses the gasket to form an impenetrable, gas-tight, and liquid-tight seal against high internal working pressures.
Under ASME B16.5 specifications, Class 150 and Class 300 flanges feature a standard 1/16-inch (1.6 mm) raised face height. For heavy-duty high-pressure classes—including Class 600, 900, 1500, and 2500—the raised face height increases to 1/4-inch (6.4 mm) to prevent flange-to-flange metal contact while maximizing localized gasket seating stress under elevated bolt loading.
The primary function of a Raised Face Flange is to direct maximum compressive strain into the gasket material without incurring flange rotation or bolting yield. Shanxi Yuxin Casting & Forging Co., Ltd. utilizes precision CNC facing lathes to machine standardized phonographic and concentric serrated finishes on all RF surfaces, strictly complying with customer specifications and international piping codes:
Tailored metallurgy and forging configurations engineered to survive aggressive thermal cycling, corrosive media, and structural vibration.
Forged carbon steel ASTM A105 and low-temperature A350 LF2 raised face flanges applied in wellhead manifolds, crude transportation lines, and refinery hydrocrackers. NACE MR0175 / ISO 15156 sour service compliance ensures resistance against Hydrogen-Induced Cracking (HIC) and Sulfide Stress Cracking (SSC).
High-alloy ASTM A182 F11/F22/F91 Weld Neck Raised Face flanges designed for high-pressure main steam lines and feed-water heater loops. Subjected to 100% volumetric Ultrasonic Testing (UT) and High-Temperature Creep Resistance analysis.
Austenitic stainless steel ASTM A182 F304/F304L and F316/F316L RF slip-on and blind flanges resisting highly aggressive organic acids, chlorine compounds, and solvent vapor recovery systems.
Duplex stainless steel ASTM A182 F51 (S31803) and Super Duplex F53 (S32750) raised face flange assemblies built to resist seawater pitting, crevice corrosion, and heavy wave-slap mechanical dynamics.
Ultra-low temperature impact-tested (Charpy V-notch down to -196°C) stainless steel RF weld neck flanges supporting liquid natural gas storage, bunkering lines, and high-pressure gaseous hydrogen logistics.
Understanding total cost of ownership, raw material traceability, and industrial forging scale in Shanxi, China.
The global industrial flange procurement market has undergone a structural shift toward integrated, high-capacity manufacturing clusters capable of delivering verifiable quality at scale. Shanxi Province—specifically Dingxiang County, recognized globally as the “Hometown of Forging in China”—stands at the epicenter of this supply chain evolution. Shanxi Yuxin Casting & Forging Co., Ltd. operates directly within this industrial ecosystem, maintaining absolute end-to-end control from steel billet selection to final CNC serration lathe operations.
In high-pressure piping systems, specifying cast flanges introduces significant risks of micro-porosity, gas inclusions, and structural fatigue under thermal shock. Yuxin exclusively manufactures 100% hot forged flanges, utilizing heavy hydraulic forging presses and ring-rolling machines that realign the internal grain flow of the steel along the contour of the flange body. This dense directional grain flow guarantees superior tensile strength, higher impact toughness, and complete structural reliability under cyclic pressure surges.
| Material Grade | Standard Specification | Tensile Strength (MPa) | Yield Strength (MPa) | Primary Industrial Application |
|---|---|---|---|---|
| ASTM A105 | ASME B16.5 / B16.47 | ≥ 485 | ≥ 250 | General Ambient Oil, Gas & Steam Pipelines |
| ASTM A350 LF2 Class 1 | ASME B16.5 / MSS SP-44 | 485 - 655 | ≥ 250 | Low Temperature Service (-46°C Impact Tested) |
| ASTM A182 F304 / 304L | ASME B16.5 / EN 1092-1 | ≥ 485 / ≥ 415 | ≥ 205 / ≥ 170 | Chemical Processing & Food Grade Hygienic Lines |
| ASTM A182 F316 / 316L | ASME B16.5 / EN 1092-1 | ≥ 485 / ≥ 415 | ≥ 205 / ≥ 170 | Marine Seawater, Acidic Media & Sour Gas |
| ASTM A182 F51 (UNS S31803) | ASME B16.5 / EN 1092-1 | ≥ 620 | ≥ 450 | Offshore Oil Rigs, Desalination & High Chloride |
Every shipment is backed by audited quality management systems and comprehensive material verification documentation.
Factory Quality System audited and verified by TÜV CERT under ISO 9001:2015 management frameworks and European Pressure Equipment Directive (PED 2014/68/EU) Module H guidelines.
Full material heat number identification stamped directly onto each flange outer diameter. Every order includes official Mill Test Reports detailing chemical spectral analysis, mechanical tensile/yield test results, and heat treatment logs.
In-house quality control procedures including Ultrasonic Testing (UT) per ASTM A388 for internal void detection, Magnetic Particle Inspection (MT) for carbon steels, and Liquid Penetrant Testing (PT) for stainless steel grades.
Pioneering smart manufacturing, AI-assisted quality control, and zero-emission green metallurgical processes.
As global engineering requirements move toward zero-emissions plant operations and automated construction, Shanxi Yuxin Casting & Forging Co., Ltd. is actively investing in next-generation manufacturing technology to maintain industry leadership:
Development of Raised Face flanges pre-machined with micro-channel recesses to accommodate fiber-optic leak detection sensors and IoT strain gauges, providing real-time bolt load and sealing integrity telemetry for automated refinery plants.
Implementation of non-contact 3D laser profilometry across CNC lathe finishing lines to automatically verify serration peak-to-valley geometry (Ra, Rz values) down to sub-micron accuracy, eliminating human measurement variance.
Transition of forging billet reheating equipment from natural gas to natural gas-hydrogen blend and clean electricity induction heating, reducing the carbon footprint per ton of forged steel by over 35% by 2028.
Complete pipe connection solutions supporting international ANSI/ASME, EN, DIN, and JIS standard requirements.
Direct answers from our senior engineering desk regarding design codes, gasket compatibility, and order execution.
The Raised Face design concentrates the total bolt clamping load onto a smaller, defined gasket area elevated above the bolting flange plane. This generates significantly higher localized seating stress, achieving a reliable pressure seal at lower torque values compared to Flat Face (FF) flanges, which compress gaskets across the entire flange face area.
Caution is mandatory. Bolting a carbon steel or stainless steel RF flange directly to a cast iron FF flange (such as on pumps or valves) is strongly discouraged. The point load exerted by the 1/16" raised face can create severe bending moments in the cast iron flange, leading to structural cracking. When joining RF to FF equipment, engineers usually specify flat face companion flanges or full-face gaskets with controlled torqueing sequences.
We provide two standard serration finishes in strict compliance with ASME B16.5: Stock Finish (spiral phonographic serrations with 125–250 µin AARH / Ra 3.2–6.3 µm) and Concentric Serrations. Smooth finish (Ra < 3.2 µm) is also available upon request for metallic spiral wound gaskets equipped with flexible graphite fillers.
We forge Raised Face flanges across all standard pressure classes including ASME Class 150, 300, 600, 900, 1500, and 2500, as well as European EN 1092-1 PN6 through PN400. Nominal pipe sizes range from 1/2" up to 120" (DN15 to DN3000). Larger diameter non-standard rings are forged on our heavy ring-rolling mill according to customer engineering drawings.
Every shipment is accompanied by a certified EN 10204 3.1 Mill Test Certificate (3.2 third-party witness available upon request). This documentation includes chemical heat spectral analysis, room temperature and low-temperature tensile and impact test results, heat treatment logs, hardness numbers, dimensional inspection sheets, and non-destructive examination (UT/MT/PT) reports.
All machined Raised Face surfaces are coated with a heavy rust-inhibiting transparent varnish or hard yellow rust-preventive oil, followed by plastic protective cap covers over the facing and bore. Flanges are packed securely inside fumigation-free plywood cases or heavy-duty steel framed crates equipped with desiccant packs to prevent transit oxidation.
