Alloy 20 Couplings in sizes 2” & 3”
Alloy 20 (also called Carpenter 20Cb-3®) is an austenitic stainless steel possessing excellent resistance to hot sulfuric acid and many other aggressive environments which would readily attack Type 316 stainless. This alloy exhibits superior resistance to stress-corrosion cracking in boiling 20 to 40% sulfuric acid.

20Cb-3 stainless is also stabilized to limit inter-granular attack, even in the sensitized condition. Corrosion tests on annealed and sensitized material conducted in the Ferric Sulfate - 50% Sulfuric Acid Test resulted in rates of 0.002 inches per month maximum.

This material has found wide use in all phases of the chemical and allied industries. It has been used extensively in the processing of synthetic rubber, high-octane gasoline, solvents, explosives, plastics, synthetic fibers, heavy chemicals, organic chemicals, pharmaceuticals, and agrichemicals.
  Some of the areas of use for Alloy 20 are:

Mixing tanks
Distillation towers
Heat exchangers
Process piping
Bubble caps
Metal cleaning & pickling tanks spray Pickling equipment
Pump shafts and rods valve stems
Tie rods
Continuous-line pickling equipment

Important Note: The following 5-level rating scale is intended for comparative purposes only. Corrosion testing is recommended; factors which affect corrosion resistance include temperature, concentration, pH, impurities, aeration, velocity, crevices, deposits, metallurgical condition, stress, surface finish and dissimilar metal contact.
Nitric Acid Good   Sulfuric Acid Excellent
Phosphoric Acid Good   Acetic Acid Good
Sodium Hydroxide Good   Salt Spray (NaCl) Excellent
Sea Water Moderate   Sour Oil/Gas Good
Humidity Excellent      
Please see dimensions, weights and complete technical specifications for Alloy 20 couplings in our Catalog on pages 9, 11, 12, and 13.