Description
Large Diameter Steel Pipe Flanges (specifically engineered under ASME B16.47 Series A and Series B standards) are high-strength forged pipe connectors designed for heavy-duty transmission pipelines, oil refineries, power plants, and municipal water networks. Ranging from 26 inches up to 60 inches (DN650 to DN1500) and beyond, these large-bore flanges provide exceptional pressure containment, structural rigidity, and reliable bolt-load distribution under severe mechanical stress.
Manufactured using advanced open-die ring forging and CNC precision machining, these heavy-duty flanges serve as core connections alongside our industrial butterfly valves and form complete, leak-free pipeline loops on our industrial flanges production lines.
Technical Specifications
| Technical Parameter | Specification Details |
|---|---|
| Nominal Diameter Range | 26″ to 60″ (DN650 to DN1500) Standard; Up to 102″ (DN2600) Custom |
| Pressure Class Ratings | Class 75, Class 150, Class 300, Class 600, Class 900 |
| Flange Types Available | Weld Neck (WN), Slip-On (SO), Blind (BL), Lap Joint |
| Material Grade Options | Carbon Steel (ASTM A105 / A350 LF2), High-Yield Steel (API 5L F42-F70), Stainless Steel (304/304L, 316/316L, Duplex 2205) |
| Facing Type & Finish | Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ); Stock Finish (125-250 AARH) or Smooth Finish |
| Manufacturing Standards | ASME B16.47 (Series A / MSS SP-44 & Series B / API 605), AWWA C207, DIN 2501, EN 1092-1 |
| Testing & Inspection | 100% Ultrasonic Testing (UT), Magnetic Particle Testing (MT), Dimensional & PMI Verification |
Key Features & Engineering Integrity
Connecting large-scale pipelines demands severe-duty forging integrity and strict dimensional tolerances:
- Heavy-Duty Seamless Forging: Advanced hydraulic forging presses ensure refined grain structure, superior fatigue resistance, and zero internal void defects under high bending moments.
- ASME B16.47 Series A vs. Series B Versatility: Series A flanges offer thicker profile dimensions and heavier bolt circles for severe pipeline loads, while Series B flanges provide compact, lighter configurations for space-restricted process lines.
- Precision CNC Gasket Surface Machining: Serrated spiral concentric grooves machined strictly to standard tolerances ensure uniform gasket compression and long-term zero leakage.
Target Applications & Industries
Our large diameter forged steel flanges are relied upon in major international infrastructure projects:
- Oil & Gas Transmission Lines: Cross-country natural gas pipelines, crude oil trunklines, and offshore platform headers.
- Municipal Water & Wastewater Infrastructure: High-volume water transmission mains, sewage treatment lines, and desalted water transport.
- Power Generation & Chemical Plants: Steam condenser piping, cooling water loops, and heavy process vessels.
Frequently Asked Questions (FAQ)
Q1: What is the main difference between ASME B16.47 Series A and Series B flanges?
Series A (formerly MSS SP-44) flanges are heavier, thicker, and use larger bolts, making them suited for higher external piping loads. Series B (formerly API 605) flanges are lighter, have smaller bolt circles, and use a larger quantity of smaller bolts, offering a lower overall weight.
Q2: Can Oucang Valve manufacture non-standard large flanges according to customer drawings?
Yes. In addition to ASME and AWWA standard flanges, we manufacture custom large-diameter forged rings and non-standard flanges up to 102 inches based on customer engineering drawings and finite element analysis (FEA).
Q3: What non-destructive testing (NDT) is performed on large forgings?
Every large diameter flange undergoes Ultrasonic Testing (UT) per ASTM A388 to detect internal porosity or inclusion defects, alongside Positive Material Identification (PMI) for material grade confirmation.
About the Manufacturer: Oucang Valve
Oucang Valve is an ISO-certified direct manufacturer specializing in heavy-duty forged steel flanges, industrial pipe fittings, and high-performance pipeline valves. Operating our own ring forging shop, large-capacity CNC machine center, and physical/chemical testing lab, we provide EN 10204 3.1 material test certificates and custom OEM solutions for international engineering projects.
- Core Capability: Heavy seamless ring forging, ASME B16.47 / AWWA precision machining, full NDT testing, and rapid export packaging.
- Quality Compliance: ASME B16.5, ASME B16.47, AWWA C207, EN 1092-1, DIN, and ISO standards.
- Factory Inquiry: Contact our engineering sales team for direct factory quotations, material test reports, and 2D/3D CAD drawings.
