Engineered to rigid international standards for oil & gas, petrochemical, marine, and power applications.
An authoritative guide to material selection, stress distribution, and sealing technology in industrial piping isolation.
In high-pressure, thermal, and corrosive fluid conveyances, the Blank Flange (commonly referred to as a Blind Flange or blanking plate) serves as an indispensable structural component. Unlike hubbed weld neck flanges or slip-on flanges, a blank flange is forged without a center bore. It functions as a definitive mechanical seal, terminating pipe ends, closing vessel nozzles, and facilitating future line expansions or routine internal maintenance access.
From a mechanical engineering perspective, blank flanges sustain maximum hoop stress and bending moments under system pressure hydrostatic tests. When installed at line terminals, the entire internal fluid force reacts directly against the flat disc face, transferring massive tensile loads onto the perimeter stud bolts and flange ring. Therefore, sourcing from a verified blank flanges manufacturer with certified forging capabilities, such as Shanxi Yuxin Casting & Forging Co., Ltd. (operating in China’s premier forging hub of Dingxiang since 1992), is critical to prevent mechanical yield, gasket blowout, or catastrophic stress corrosion cracking (SCC).
Many low-cost suppliers produce blank flanges by flame-cutting or plasma-cutting circular discs directly from rolled steel plates. Plate-cut blanks suffer from directional grain orientation, internal laminations, and reduced impact toughness at sub-zero temperatures. In contrast, YUXIN’s closed-die hot forged blank flanges undergo heavy radial plastic deformation, refining the grain structure into a continuous, unbroken metallurgical flow line aligned with the flange geometry. This delivers superior tensile yield strengths, elevated fatigue limits, and total resistance to pressure spikes in Class 1500 and Class 2500 services.
To assist EPC piping engineers, procurement managers, and mechanical designers in intent-driven sourcing, the following matrix outlines standard manufacturing parameters for high-performance blank flanges:
| Standard Specification | Pressure Class / Nominal Pressure | Nominal Size Range (DN / NPS) | Primary Material Grades | Sealing Facing Types |
|---|---|---|---|---|
| ASME B16.5 | Class 150, 300, 400, 600, 900, 1500, 2500 | 1/2" to 24" (DN15 - DN600) | ASTM A105, A350 LF2, A182 F304/F304L, A182 F316/F316L, A182 F51 (Duplex 2205) | Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ), Male & Female (M&F) |
| ASME B16.47 (Series A & B) | Class 75, 150, 300, 400, 600, 900 | 26" to 60" (DN650 - DN1500) | Carbon Steel A105, Low Temp Steel A350 LF2, High-Yield A694 F52/F60/F65 | Raised Face (RF), Ring Type Joint (RTJ) |
| EN 1092-1 (Type 05) | PN 2.5, PN 6, PN 10, PN 16, PN 25, PN 40, PN 63, PN 100 | DN 10 to DN 2000 | P245GH, P250GH, P280GH, C22.8, 1.4301, 1.4404, 1.4462 (Duplex) | Type A (Flat), Type B1/B2 (Raised Face), Type C/D (Tongue & Groove) |
| DIN Standards (DIN 2527) | PN 6 to PN 100 | DN 10 to DN 1000 | RSt37-2, C22.8, 1.4541, 1.4571 (316Ti) | Form A, Form B, Form C, Form D, Form E |
| JIS B2220 / GOST 12836 | 5K, 10K, 16K, 20K, 30K / PN 6 to PN 100 | 15A to 1500A / DN 10 to DN 1200 | SS400, SF440A, SUS304, SUS316 / Steel 20, 09G2S, 12X18H10T | RF, FF, Concentric Serrated, Smooth Finish |
Navigating total cost of ownership, risk mitigation, and supply chain reliability in international flange procurement.
Global procurement desks demand 100% material traceability. Every single YUXIN blank flange is hard-stamped with heat numbers tied directly to EN 10204 3.1 chemical analysis and mechanical testing, with independent 3.2 third-party inspection (TÜV, DNV, SGS, Lloyd's) upon request.
For European EPC projects and pressure vessel applications, compliance with the Pressure Equipment Directive (PED) and AD 2000-Merkblatt W0 is mandatory. Factory audit credentials eliminate import hold-ups and regulatory rejections at destination ports.
Proper gasket seat contact requires strict adherence to surface roughness parameters. Our CNC lathes deliver standard stock finishes (125–250 µin AARH/Ra 3.2–6.3 µm serrated spiral or concentric) or smooth finishes (< 63 µin Ra) for special metallic spiral wound gaskets.
Procurement professionals in Tier-1 engineering firms evaluate suppliers on total lifecycle costs rather than initial purchase price alone. A single defective blank flange in an offshore hydrocarbon pipeline can lead to localized leakage, emergency shut-downs, environmental remediation fines, and massive financial loss. Sourcing high-integrity forged blank flanges minimizes supply chain risk through:
Deploying specialized blank flanges across critical global infrastructure and energy projects.
Utilized on Christmas trees, manifold tie-ins, FPSO topsides, and subsea pipelines. Heavy-duty Class 1500 and Class 2500 Ring-Type Joint (RTJ) blank flanges withstand operating pressures up to 10,000 PSI under harsh marine atmospheric corrosion.
Installed at heat exchanger nozzles, catalytic cracking units, and storage tank isolation points. High-alloy stainless (F316L) and Duplex steel blank flanges resist aggressive organic acids, high-temperature sulfur compounds, and chloride pitting.
Used for steam header blanking, feed-water isolation, and boiler pressure boundary hydrostatic verification. ASTM A182 F11/F22 chrome-moly alloy steel blank flanges ensure extreme creep resistance at temperatures exceeding 550°C.
Large-diameter EN 1092-1 PN10/PN16 blank flanges up to DN 3000 installed in sea water reverse osmosis (SWRO) desalination facilities and trunk distribution lines, featured with non-toxic epoxy lining for potable water compliance.
Certified by major marine classification bodies (DNV-GL, ABS, BV, LR). Applied in ballast water treatment systems, engine room fuel oil headers, and cargo hold pumping systems where compact design and high fatigue strength are vital.
Heavy-wall blank flanges manufactured with abrasion-resistant alloy cladding or rubber linings to withstand high-velocity abrasive slurries and concentrated nitric/phosphoric acid streams without premature erosion-corrosion.
Pioneering Industry 4.0 digitised production, automated non-destructive testing, and sustainable metallurgy.
The manufacturing landscape for industrial piping components is undergoing a profound digital transformation. To maintain a competitive edge as a top-tier blank flanges supplier, Shanxi Yuxin Casting & Forging Co., Ltd. has established an integrated technology roadmap bridging traditional forge craftsmanship with AI-driven quality control.
Our facility utilizes high-capacity hydraulic forging presses paired with CNC radial-axial ring rolling machines. This dual manufacturing route allows us to forge solid blank flange discs up to 3,000 mm (120 inches) in diameter with near-net-shape accuracy. By minimizing machining stock allowances, we achieve optimal material yield while preserving uniform grain flow along the outer perimeter where stress concentrations peak.
Mechanical properties of carbon steel (A105, A350 LF2) and alloy forgings are strictly determined by heat treatment precision. YUXIN operates gas-fired, PLC-controlled continuous heat-treatment furnaces equipped with multi-point thermocouples. Fully documented normalization, quenching, and tempering cycles guarantee consistent tensile, yield, elongation, and Charpy V-notch impact values down to -46°C for arctic service conditions.
To ensure 100% internal sound structural integrity before shipping, every blank flange undergoes rigorous NDT testing in compliance with customer quality control plans (QCP):
Looking ahead toward 2030, YUXIN is adopting green forging technology powered by electric induction heating furnaces to reduce carbon intensity per ton of forged output. Additionally, we are implementing QR-code embedded digital passports on mill test certificates, allowing field engineers to scan flanges at project sites and instantly retrieve heat treatment curves, spectral readings, and dimensional inspection logs from cloud databases.
Seamless cross-border delivery, regional standard alignment, and export-ready protective packaging.
Heavy forged flanges are securely packed in ISPM-15 compliant fumigation-free plywood crates, steel-banded pallets, or custom wooden boxes. Flange faces are individually protected with plastic cap covers and heavy VCI rust-inhibitor wrap.
Our dedicated international sales engineering team provides 24/7 technical support in English, German, Spanish, and Russian. We handle complex bid packages, MTO (Material Take-Off) reviews, and RFQ responses within 24 hours.
Holding ISO 9001:2015 Quality Management System, PED 2014/68/EU Directive, AD 2000-Merkblatt W0, and Special Equipment Manufacturing License of China. Approved vendor for leading global EPC contractors and national oil companies.
Expert responses to critical questions from piping designers, quality auditors, and procurement leads.
In industry terminology, the terms Blank Flange and Blind Flange are synonymous. Both refer to a solid forged flange without a center bore used to blank off a pipeline end, valve outlet, or pressure vessel nozzle. However, a "blank flange" can also refer to a machining blank prior to final drilling, or to a paddle blank (spectacle blind component) used in line isolation double block and bleed arrangements.
Selection depends primarily on system pressure class and operating fluid temperature:
Yes. Beyond standard ASME B16.5, ASME B16.47, and EN 1092-1 series, Shanxi Yuxin Casting & Forging Co., Ltd. routinely manufactures non-standard blank flanges, heavy-wall forged discs, special tube sheets, and custom forged rings up to 3,000 mm in diameter. Our in-house tooling shop can develop dies directly from customer CAD/PDF drawings and service condition specifications.
Every shipment is accompanied by a comprehensive document dossier containing:
Standard carbon steel blank flanges (A105, Q235B) in common sizes (1/2" to 24") are maintained as semi-finished forged stock and can ship within 7 to 15 days after final CNC facing and drilling. For custom alloy forgings, large-diameter items (> 36"), or specific heat treatment orders, typical production lead time is 20 to 35 days. We accommodate low MOQ for trial orders and distributor stock replenishment.
Plate steel exhibits directional anisotropic properties, meaning tensile toughness is lower in the transverse and through-thickness (Z-axis) directions. Flame cutting can also create heat-affected zones (HAZ) along the outer perimeter prone to micro-cracking. Forging mechanically compresses the metal matrix, refining the grain structure evenly across three dimensions and eliminating voids, providing maximum pressure containment safety.
Complete piping component solutions direct from our Shanxi manufacturing plant.
