Sulfuric Acid Resistant Nickel-Chromium-Molybdenum-Copper Alloy Fittings
MicroTech Stainless Steel Co. offers premium Alloy 20 (UNS N08020) Pipe Fittings, an austenitic nickel-chromium-molybdenum-copper alloy specifically designed for superior resistance to sulfuric acid and chloride-induced corrosion. Originally developed for sulfuric acid service, Alloy 20 provides exceptional resistance to stress corrosion cracking, pitting, and crevice corrosion in chloride-contaminated environments.
The unique composition featuring 33% nickel, 20% chromium, 2.5% molybdenum, and 3% copper delivers outstanding performance in sulfuric acid concentrations up to 40% at temperatures up to 212°F (100°C), mixed acids including sulfuric-nitric, phosphoric acid, and various chemical processing environments. The niobium stabilization prevents intergranular corrosion after welding and thermal exposure.
Our Alloy 20 fittings are manufactured to ASME B16.9 and ASTM B366 standards in butt weld configuration including elbows, tees, reducers, caps, and stub ends. Available in sizes from 1/2" to 12", each fitting undergoes comprehensive testing including PMI verification, intergranular corrosion testing (ASTM A262 Practice E), and dimensional inspection to ensure reliable performance in chemical processing, pharmaceutical, petrochemical, and food processing applications.
Outstanding resistance to sulfuric acid concentrations up to 40% at temperatures up to 212°F (100°C). Superior to stainless steels in dilute sulfuric acid service.
Excellent resistance to chloride-induced stress corrosion cracking. High nickel content (33%) combined with molybdenum provides superior pitting and crevice corrosion resistance.
Niobium (Columbium) addition prevents intergranular corrosion after welding and thermal exposure. Eliminates sensitization concerns in heat-affected zones.
Excellent resistance to sulfuric-nitric acid mixtures, phosphoric acid, and other mixed chemical environments common in multi-purpose chemical plants.
Maintains corrosion resistance after exposure to sensitizing temperatures (800-1500°F). Suitable for applications with intermittent thermal cycling.
Over 70 years of successful service in sulfuric acid alkylation, chemical processing, and pharmaceutical applications. Proven track record in demanding environments.
Sulfuric acid plants, phosphoric acid production, nitric acid-sulfuric acid mixtures, mixed acid pickling, and multi-purpose chemical reactors handling aggressive media.
API manufacturing, pharmaceutical synthesis, reactor vessels, crystallizers, and high-purity process equipment requiring sulfuric acid resistance with cleanability.
Sulfuric acid alkylation units, spent acid recovery systems, acid regeneration, sour water strippers, and refinery processes involving sulfuric acid catalyst.
Phosphoric acid production, sulfuric acid handling, DAP/MAP fertilizer plants, ammonium sulfate production, and acidulation processes.
Food-grade phosphoric acid systems, citric acid production, pickling operations, and food industry applications requiring corrosion resistance with hygiene.
Nuclear fuel reprocessing, radioactive waste handling, rare earth extraction, and specialty chemical production requiring both corrosion and radiation resistance.