Large Diameter Forged Flange
We manufacture large diameter forged flanges from NPS 14" to 160" (DN350 to DN4000) designed for heavy-duty industrial piping systems that demand high mechanical load capacity and strict dimensional tolerance.
- Product Introduction
Product Overview
We manufacture large diameter forged flanges from NPS 14" to 160" (DN350 to DN4000) designed for heavy-duty industrial piping systems that demand high mechanical load capacity and strict dimensional tolerance.
Our flanges are engineered from selected, premium steel billets or integrated forged rings through controlled heavy-duty forging processes. This mechanical working refines the internal grain structure, eliminates internal porosity, and ensures absolute material integrity throughout the component cross-section. As an ISO 9001 and PED certified manufacturer, we support global stocking distributors and EPC contractors with fully traceable materials, competitive lead times, and reliable production schedules.
Technical Advantages & Manufacturing Capabilities
1. Grain Alignment for Structural Reliability
Large-diameter piping systems frequently operate under extreme combined stresses, including high internal pressure, thermal expansion, and external bending moments.
Controlled Hot Forging: We utilize advanced open-die and hydraulic ring-rolling processes that align the metal's grain flow with the final geometric contour of the flange. This directional grain structure significantly increases yield strength and impact fatigue resistance compared to plate-cut or cast alternatives.
Internal Soundness: The high reduction ratios executed during our heavy forging processes eliminate internal shrinkage cavities and blowholes, ensuring reliable, long-term performance under cyclic loading conditions.
2. Precision CNC Machining & Facing Consistency
Dimensional control in large-bore connections is critical to prevent bolt misalignment and uneven gasket compression, which are the leading causes of flange leakage.
Tolerances: Utilizing large-scale CNC vertical lathes, we maintain strict control over Bolt Circle Diameter (BCD), hole alignment, and flange thickness well within international tolerance limits.
Surface Finishes: Flange faces are precision-machined to standard specifications, including Stock Finish, Smooth Finish, or Concentric/Spiral Serrated finishes (Ra 3.2 to 6.3 μm or 125 to 250 μin AARH) to ensure proper gasket seating.
3. Standardized Heat Treatment & Testing
To achieve targeted mechanical properties and compliance with strict project specifications, all forgings undergo rigorous thermal processing based on material grade:
Thermal Processing: Digitally monitored furnaces execute precise Normalizing, Quenching & Tempering (Q+T), or Solution Annealing cycles to relieve residual stresses, optimize hardness, and enhance low-temperature impact toughness.
Non-Destructive Testing (NDT): In-house Ultrasonic Testing (UT) and Magnetic Particle Testing (MT) are performed per project specifications to verify internal soundness and surface integrity before final machining.
Core Applications
Our large diameter flanges are engineered to perform in the world's most demanding environments, providing structural integrity for high-stakes projects across:
Oil & Gas
Offshore production platforms, subsea pipelines, and refinery piping networks.
Power Generation
Thermal, hydro, and nuclear power plant cooling systems.
Renewable Energy
Wind turbine tower structural foundation rings.
Water Infrastructure
Desalination plants, large-scale municipal water treatment pipelines, and high-pressure pumping stations.
Heavy Chemical
Petrochemical vessels, heat exchangers, and processing reactors.
Technical Specifications
|
Item |
Technical Details & Range |
|
Size Range |
NPS 14" to 160" / DN350 to DN4000 (Custom oversized dimensions available upon request) |
|
Pressure Ratings |
ASME Class 150, 300, 600, 900, 1500, 2500 / PN6 to PN400 |
|
Design Standards |
ASME B16.47 (Series A & Series B), ASME B16.5, API 6A, EN 1092-1, DIN |
|
Flange Types |
Welding Neck (WNF), Blind (BLN), Slip-On (SOF), Hubbed Flanges, Custom Forged Rings |
|
Carbon Steel |
ASTM A105 / A105N, ASTM A350 LF2 Class 1/2 (Low Temperature), ASTM A694 F42 to F70 |
|
Stainless Steel |
ASTM A182 F304/304L, F316/316L, Dual Grades |
|
Duplex & Super Duplex |
ASTM A182 F51 (UNS S31803), F53 (UNS S32750), F55 (UNS S32760) |
|
Alloy & Nickel Alloys |
ASTM A182 F11, F22, F5, F91 | Nickel Alloy 625, Alloy 825, Monel 400 |
|
Quality Certification |
EN 10204 3.1 Mill Test Certificate (MTC), Third-Party Inspection (SGS, BV, TUV, DNV) |
Quality Control & Material Traceability
Inbound Inspection: Every raw material steel billet is verified for chemical composition via spectroanalysis, and original heat numbers are hard-stamped and tracked through all production stages.
Process Documentation: We maintain independent, fully auditable paper trails for digitally logged heat treatment charts, dimensional inspection sheets, and NDT reports to ensure compliance with project specifications.
In-House Processing: By managing the forging, heat treatment, and CNC machining within our own facilities, we maintain direct control over both production timelines and final product quality, eliminating outsourcing risks.
FAQ
Q: What is the primary difference between ASME B16.47 Series A and Series B flanges?
A: Series A (based on MSS SP-44): Thicker, heavier, and utilizes larger but fewer bolts. It is commonly selected for general industrial piping infrastructure where external piping loads, bending moments, and structural stresses are higher.
Series B (based on API 605): Thinner, lighter, and utilizes smaller but more numerous bolts. It is typically specified for compact spaces, pipeline modifications, or compact valve connections where minimizing total weight and footprint is a priority.
Q: Why is forging preferred over casting or plate-cutting for large bore applications?
A: Forging provides a continuous, directional grain flow that follows the physical contour of the flange, resulting in significantly higher impact toughness, yield strength, and fatigue resistance under high pressure. Castings are inherently susceptible to internal volumetric defects like porosity and shrinkage, while plate-cut flanges can exhibit reduced through-thickness tensile properties, risking lamellar tearing under heavy structural loads.
Q: What documentation is provided with the shipment?
A: Every shipment is accompanied by a standard EN 10204 3.1 Mill Test Certificate (MTC). This comprehensive document outlines the actual chemical ladle analysis, mechanical test results (tensile, yield, elongation, and low-temperature impact toughness where applicable), heat treatment method/charts, and NDT verification records. Third-party inspection reports (SGS, BV) are provided if requested at the time of order placement.
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