When facing extreme environments characterized by high chlorides, strong acids, or intense mechanical loads, conventional austenitic stainless steels often reach their limits. Jiangyin Zhonghai Precision Machinery Co., Ltd. manufactures Duplex Steel Flanges that combine the high strength of ferrites with the superior corrosion resistance of austenites, making them the premier choice for the Oil & Gas, Marine Engineering, and Chemical Processing industries.

Beyond manufacturing standard components according to ASME, DIN, EN, and JIS, we leverage our fully integrated in-house forging, heat treatment, and precision machining capabilities to support custom requirements up to 60" and single-piece weights of 10 tons. Every Zhonghai Duplex flange undergoes rigorous phase-balance testing to ensure unparalleled reliability under extreme pressure ratings (up to 2500lb).

Core Advantages
·Full Vertical Integration: We manage the entire lifecycle—from raw material forging to critical heat treatment and CNC machining—ensuring precise control over the duplex microstructure.
·Global Certifications: ISO 9001 certified with PED (Pressure Equipment Directive) and TS credentials, meeting the highest international safety and quality standards.
·Scale & Precision: Capable of handling diameters up to 4 meters and components up to 10 tons, covering the full spectrum of pressure classes from 150lb to 2500lb.
·Custom Bespoke Solutions: Whether it is a complex non-standard structure or a specific material grade, we provide rapid evaluation and delivery from "small-batch prototyping" to "mass production" based on your blueprints.

Key Features
·Exceptional Stress Corrosion Cracking Resistance: The unique dual-phase structure provides significantly higher resistance to pitting and crevice corrosion in chloride-rich environments compared to standard stainless steels.
·High Yield Strength: Approximately double the strength of standard austenitic grades, allowing for weight reduction in equipment design without compromising safety.
·Optimized Heat Treatment: Precise control of solution annealing temperatures and cooling rates prevents harmful phase precipitation, ensuring an ideal balance of physical properties.
·Precision Sealing Interface: Advanced CNC turning ensures tight tolerances on sealing faces, guaranteeing zero-leakage performance under high pressure and vibration.

Applications
·Marine & Offshore: Offshore drilling platforms, desalination systems, and subsea pipeline connections.
·Oil & Gas: Transport and processing equipment handling corrosive media like H2S and CO2.
·Chemical Processing: Chloride processing and bleaching systems in the pulp and paper industry.
·Energy Sector: Nuclear power, Flue Gas Desulfurization (FGD), and high-pressure vessel interfaces.