Direct factory supply from Shanxi Yuxin Casting & Forging Co., Ltd. ISO 9001 & PED Certified production line.
In high-pressure fluid transportation, thermal processing, and industrial pipeline networks, specifying the correct piping flange requires a rigorous understanding of standard classifications. The designation DN (Diamètre Nominal) represents the metric standard for pipe sizing used universally under European (EN 1092-1), German (DIN), and International (ISO) frameworks. Unlike the Imperial NPS (Nominal Pipe Size) system governed by ASME B16.5, DN flanges are engineered around exact metric bore dimensions and pressure ratings expressed in Bar (PN - Pressure Nominal).
DN values (such as DN15, DN50, DN300, up to DN3000) correspond directly to the internal flow path diameter of matching pipe schedules. When sourcing from a China DN flanges manufacturer, alignment between the pipe’s outer diameter (OD), wall thickness (WT), and flange bore tolerance is critical to prevent turbulent backpressure and localized erosion-corrosion.
Pressure Nominal (PN) ratings define the maximum permissible operating pressure in bars at ambient temperature (+20°C). Global procurement officers must navigate cross-standard specifications: PN6, PN10, PN16, PN25, PN40, PN63, and PN100. While Class 150 roughly aligns with PN20 and Class 300 with PN50, bolt hole patterns, pitch circle diameters (PCD), and facing elevations differ significantly.
| Nominal Diameter (DN) | Imperial Equivalent (NPS) | EN 1092-1 Standard Rating | ASME B16.5 Standard Class | Primary Flange Facing Types | Critical Engineering Application |
|---|---|---|---|---|---|
| DN 15 - DN 50 | 1/2" - 2" | PN 10 - PN 400 | Class 150 - 2500 | Raised Face (RF), Male/Female (M/F) | Chemical dosing, hydraulic pilot lines, high-pressure instrument manifolds |
| DN 65 - DN 300 | 2-1/2" - 12" | PN 6 - PN 160 | Class 150 - 900 | RF, Tongue & Groove (T/G), RTJ | Hydrocarbon transmission, refinery steam loops, municipal water mains |
| DN 350 - DN 1200 | 14" - 48" | PN 2.5 - PN 100 | Class 150 - 600 (Series A/B) | Flat Face (FF), Raised Face (RF) | Offshore platform risers, cross-country gas trunklines, power condenser loops |
| DN 1300 - DN 3000 | 52" - 120" | PN 2.5 - PN 40 | AWWA C207 / Custom DWG | Flat Face (FF), Custom O-Ring Grooves | Desalination intakes, hydroelectric penstocks, wind turbine tower flanges |
Shanxi Province, specifically Dingxiang County, is globally recognized as the undisputed “Hometown of Forging in China.” Operating within this industrial cluster, Shanxi Yuxin Casting & Forging Co., Ltd. leverages an integrated ecosystem of raw material melt shops, heavy hydraulic forge presses, automated ring-rolling mills, heat treatment furnaces, and state-of-the-art CNC machine centers.
Direct mill sourcing of prime steel ingots (ASTM A105, A350 LF2, Stainless 304/304L/316L/316Ti, Duplex 2205/2507, and Alloy A182 F11/F22) with 100% spectral chemical verification prior to hot deformation.
Annual manufacturing output exceeding 10,000 metric tons of finished flanges and 2,000 tons of custom ring forgings translates to unrivaled economies of scale and aggressive factory-direct pricing for global procurement leaders.
With thousands of semi-finished forged ring blanks kept in static inventory across standard DN classes, urgent replacement orders ship within 7 to 15 days, minimizing downtime for major EPC contractors.
A single connection failure in a high-pressure line can cause catastrophic downtime, safety hazards, and massive financial liability. As a specialized China DN flanges manufacturer, Shanxi Yuxin enforces a rigorous closed-loop quality management system certified by European and international notified bodies.
Every shipment includes an authentic Mill Test Certificate (MTC) documenting chemical ladle analysis, mechanical yield/tensile strength, elongation, Charpy V-notch impact tests at negative temperatures (-40°C), and hardness values.
Factory audited and qualified for pressure equipment exported to European Union member states. Full compliance with AD 2000-Merkblatt W0 for pressure vessel steel forgings operating under hazardous parameters.
100% Ultrasonic Testing (UT) per ASTM A388 / EN 10228 to eliminate internal voids, inclusions, and forging bursts, supplemented by Magnetic Particle (MT) and Liquid Penetrant Inspection (PT) for critical faces.
Our forged DN flanges are deployed across harsh industrial environments worldwide, engineered to solve severe mechanical stress, thermal cycling, and aggressive chemical attack:
Utilizing ASME B16.5 Class 300-1500 and EN 1092-1 PN40-PN100 High Yield Carbon Steel (A350 LF2) and Alloy Steel (A182 F11/F22) Weld Neck Flanges. Designed to withstand hydrogen attack, thermal expansion, and sour gas environments per NACE MR0175/ISO 15156 standards.
Heavy diameter DN800 to DN2400 EN 1092-1 Type 01 Slip-On and Type 11 Weld Neck Flanges forged from Stainless Steel 316L and Duplex 2205. Features zero-leakage serrated faces (125-250 AARH finish) engineered for high-salinity seawater intake and reverse osmosis skid headers.
PN16 to PN63 custom blind flanges, expansion joint flanges, and heavy tube sheets for heat exchangers. Built with high precision CNC bolt-hole alignment to permit rapid turnarounds during plant outages and thermal stress resilience.
JIS B2220 5K/10K/16K and DIN standard compact socket weld flanges designed for space-constrained engine rooms, ballast water handling, and fuel line manifolds certified by international classification societies.
As global pipeline engineering moves toward higher working pressures, elevated temperatures, and stringent ESG decarbonization mandates, industrial buyers are reshaping their vendor selection criteria.
Implementation of closed-loop optical sensors on ring-rolling equipment enables real-time wall thickness and concentricity monitoring, guaranteeing radial tolerances within +/- 0.5mm across DN1000+ rings.
Transitioning forge heating furnaces from coal gas to energy-efficient natural gas and induction heating systems, significantly reducing the embodied carbon footprint per ton of finished forged steel flange.
Multi-axis CNC turning and gang-drilling stations eliminate manual layout errors for PCD bolt circles, ensuring instant alignment on remote job sites without structural binding.
Engineered for high-integrity pressure applications. Full material test reports included.
Speak directly with our senior forging engineers. Fast inquiry response within 24 hours.
