
4A National Standard Flange Globe Valve is a high-strength, precision-control valve engineered for the most demanding corrosive environments. By utilizing 4A Duplex Stainless Steel (CD3MN) and adhering to GB/T 12233 standards, this valve provides an exceptional combination of accurate flow regulation and elite resistance to pitting and stress corrosion cracking (SCC).
Description
4A (UNS J92205 / CD3MN) is a ferritic-austenitic stainless steel that outperforms standard 300-series alloys in harsh industrial conditions:
- Erosion Resistance: The higher surface hardness of duplex steel protects the internal seating surfaces from the “wire-drawing” effect often seen during high-velocity throttling.
- Twice the Strength: The yield strength of 4A is roughly double that of 316L, allowing for a more rigid valve body that withstands higher pressure surges.
- Superior Corrosion Resistance: Specifically formulated to resist localized corrosion, making it ideal for chloride-bearing media, seawater, and aggressive chemical solutions.
Features
- Precise Throttling & Regulation: The globe-style design is optimized for flow modulation. The linear movement of the disc allows for incremental adjustments, making it the superior choice for systems requiring frequent flow tuning.
- High-Integrity Shut-off: When fully closed, the disc and seat ring provide a high-pressure seal with zero leakage, ensuring safe isolation in volatile chemical or gas lines.
- GB Standard Compliance: Fully compliant with GB/T 12233 (design), GB/T 9113 (flange), and GB/T 12221 (face-to-face), ensuring seamless integration into standardized domestic piping networks.
- Durable Stem Design: Features a rising stem with precision-ground threads to ensure smooth operation and clear visual indication of the valve’s open or closed status.
Specifications
| Feature | Specification |
| Design Standard | GB/T 12233 |
| Flange End | GB/T 9113 / JB/T 79 |
| Face-to-Face | GB/T 12221 |
| Body Material | 4A Duplex Steel (CD3MN / 022Cr22Ni5Mo3N) |
| Pressure Rating | PN16, PN25, PN40, PN64 |
| Temperature Range | -40°C to 280°C |
| Testing Standard | GB/T 13927 / JB/T 9092 |
Applications
- Chemical Processing: Accurate control of corrosive acids, organic fluids, and chemical catalysts.
- Marine & Offshore: Seawater cooling systems and offshore production platforms where chloride resistance is mandatory.
- Desalination: Brine and high-salinity water flow regulation.
- Power Generation: High-pressure feed water and chemical injection systems.




