4A National Standard Flange Ball Valve

Description

4A (ASTM A890 Grade 4A / CD3MN / 022Cr22Ni5Mo3N) is a ferritic-austenitic stainless steel designed for performance where standard 304 or 316L alloys reach their limits:

• Stress Corrosion Cracking (SCC) Defense: The dual-phase microstructure provides inherent protection against SCC, ensuring long-term integrity in pressurized chemical lines.
• Elite Corrosion Resistance: Exceptional resistance to pitting and crevice corrosion, particularly in seawater, brine, and organic acid environments.
• Double the Yield Strength: The yield strength of 4A is roughly twice that of standard austenitic stainless steels, allowing the valve body to handle higher pressure cycles and mechanical stress with ease.

Features

• GB Standard Compliance: Fully compliant with GB/T 12237 (design), GB/T 9113 (flange), and GB/T 12221 (face-to-face), ensuring seamless integration into National Standard industrial infrastructure.
• Full Bore Flow Efficiency: The internal diameter of the ball matches the pipe’s bore, providing an unobstructed flow path that minimizes turbulence and ensures negligible pressure loss.
• High-Integrity Sealing: Equipped with precision-ground 4A balls and advanced seat materials (such as RPTFE or PPL). This ensures a bubble-tight, leak-proof seal even after frequent operation.
• Fire-Safe & Anti-Static Design: Typically includes an anti-static device to discharge built-up electricity and a fire-safe structure to maintain sealing integrity in emergency high-heat scenarios.
• Easy Actuation: The quarter-turn mechanism is optimized for smooth torque, making it suitable for manual hand-levers, gear operators, or automated pneumatic and electric actuators.

Specifications

Applications

• Chemical Processing: Handling aggressive organic acids, chemical slurries, and chloride-bearing fluids.
• Marine & Offshore: Seawater cooling systems, desalination plants, and offshore production platforms.
• Oil & Gas: Upstream and midstream transport of fluids requiring high mechanical strength and corrosion defense.
• Industrial Automation: High-cycle isolation in automated chemical processing plants.