Inconel 825 (UNS N08825 / Cu28M) Butterfly Valves

Falcon High-Performance Inconel 825 (UNS N08825 / Cu28M) Butterfly Valves

At Falcon, we engineer and manufacture industrial-grade Inconel 825 Butterfly Valves designed for zero-leakage quarter-turn isolation, precise flow throttling, and maximum resistance to aggressive reducing and oxidizing acids. Cast in high-purity ASTM A494 Grade Cu28M (Cast Inconel 825) and forged from ASTM B564 / B425 UNS N08825, our Inconel 825 valves combine a high nickel-iron-chromium matrix with added molybdenum, copper, and titanium to deliver exceptional protection against sulfuric acid, phosphoric acid, chloride pitting, and intergranular corrosion.

Why Choose Falcon Inconel 825 Butterfly Valves?

• Unmatched Resistance to Sulfuric & Phosphoric Acids: The addition of copper (1.5–3.0%) combined with high nickel (38–46%) provides superior resistance to boiling sulfuric acid solutions and wet-process phosphoric acid streams.

• Immunity to Stress-Corrosion Cracking (SCC): High nickel content ensures near-complete immunity to chloride-induced stress corrosion cracking in warm, chloride-laden chemical utilities and sour oilfield environments.

• Resistance to Intergranular Corrosion: Titanium stabilization (∼0.6–1.2%) prevents sensitization during welding or thermal processing, protecting critical valve sealing faces against intergranular attack.

• High-Pitting Resistance Equivalent: Elevated chromium (∼19.5–23.5%) and molybdenum (∼2.5–3.5%) content delivers outstanding resistance to localized pitting and crevice corrosion (PREN≥31).

• Bi-Directional Zero-Leakage Performance: Available in double-offset high-performance and triple-offset metal-seated configurations to deliver certified ISO 5208 Rate A / API 598 bubble-tight shut-off.

Butterfly Valve Configurations Offered

• Double-Offset (High-Performance) Inconel 825 Butterfly Valves:

  • Design: Eccentric shaft position lifts the disc away from the seat during initial rotation, significantly reducing seat friction and wear during high-cycle throttling.

  • Best For: Acid transfer lines, pickling liquor circulation, and medium-pressure petrochemical processing.

• Triple-Offset (Bi-Directional Zero-Leakage) Inconel 825 Butterfly Valves:

  • Design: Frictionless metal-to-metal seating geometry with a laminated Inconel 825 / graphite seal ring for absolute tight shut-off under severe thermal expansion.

  • Best For: Sour gas ($H_2S$) handling, high-temperature sulfuric/phosphoric acid lines, and nuclear fuel reprocessing.

Primary Applications

• Sulfuric & Phosphoric Acid Processing: Fertilizer production, phosphoric acid concentration loops, sulfuric acid dilution, and metal pickling lines.

• Oil & Gas (Sour Service / $H_2S$): Downhole sour gas piping, gas gathering lines, and produced water handling in compliance with NACE MR0175 / ISO 15156.

• Chemical & Petrochemical Processing: Organic acid production, vinyl chloride monomer (VCM) units, and chemical washing towers.

• Nuclear & Waste Reprocessing: Dissolver tanks, nuclear fuel element recovery, and aggressive acid waste containment.

Quality Assurance & Testing Standards

Every Falcon Inconel 825 Butterfly Valve undergoes strict quality control and metallurgical verification before dispatch:

• 100% Positive Material Identification (PMI) on body, disc, and stem components
• NACE MR0175 / ISO 15156 Compliance
• Hydrostatic Shell & Bi-Directional Seat Testing per API 598 and ISO 5208.
• Non-Destructive Examination (NDE): Radiographic (RT), Liquid Penetrant (PT), and Ultrasonic (UT) testing per ASME B16.34 standards.
• EN 10204 Type 3.1 & Type 3.2 Material Test Reports (MTRs) provided for full heat number traceability.

Request a Quote or Technical Support

Protect your high-acid process lines and sour gas systems with Falcon Inconel 825 Butterfly Valves.Whether you require standard off-the-shelf dimensions or custom automated valve assemblies, our technical application team is ready to evaluate your system requirements. 

Contact Falcon Today