2205 Duplex Stainless Steel Pipe 1/8" - 36" OD For Chemical Industry
Duplex stainless steel pipe for the chemical industry is specifically engineered to withstand the aggressive corrosive environments, high pressures, and elevated temperatures commonly encountered in chemical processing facilities. The unique two-phase microstructure (austenite + ferrite) combined with high chromium, molybdenum, and nitrogen content provides exceptional resistance to a wide range of organic and inorganic chemicals.
Our duplex pipes are widely specified for chemical plants, petrochemical facilities, refineries, and specialty chemical manufacturing where standard austenitic grades such as 304 and 316 experience pitting, stress corrosion cracking, or general corrosion failure.
| Parameter | Details |
|---|---|
| Standard | ASTM A790, A789, A928, EN 10216-5, EN 10217-7, ASME B31.3 |
| Grades | 2205 (UNS S31803, S32205), 2507 (UNS S32750), 2304 (UNS S32304) |
| Size (OD) | 6.0 mm – 914 mm (1/8" – 36") |
| Wall Thickness | Schedule 5S, 10S, 40S, 80S, 160 (1.0 mm – 25.0 mm) |
| Length | 3000 mm, 6000 mm, random lengths, custom cut |
| Process | Seamless (for small diameters and high pressure) or Welded (for larger diameters) |
| Surface Finish | Annealed and pickled, Bright annealed, Mechanically polished |
| End Finish | Plain ends, Beveled ends (for welding), Threaded |
| Element | 2304 (Lean) | 2205 (Standard) | 2507 (Super) |
|---|---|---|---|
| Carbon (C) ≤ | 0.030 | 0.030 | 0.030 |
| Silicon (Si) ≤ | 1.00 | 1.00 | 0.80 |
| Manganese (Mn) ≤ | 2.50 | 2.00 | 1.20 |
| Phosphorus (P) ≤ | 0.035 | 0.030 | 0.035 |
| Sulfur (S) ≤ | 0.020 | 0.020 | 0.020 |
| Chromium (Cr) | 21.5 – 24.5 | 22.0 – 23.0 | 24.0 – 26.0 |
| Nickel (Ni) | 3.0 – 5.5 | 4.5 – 6.5 | 6.0 – 8.0 |
| Molybdenum (Mo) | 0.05 – 0.60 | 3.0 – 3.5 | 3.0 – 5.0 |
| Nitrogen (N) | 0.05 – 0.20 | 0.14 – 0.20 | 0.24 – 0.32 |
| Copper (Cu) | — | — | ≤ 0.50 |
| Grade | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Hardness (HB) |
|---|---|---|---|---|
| 2304 | ≥ 600 | ≥ 400 | ≥ 25 | ≤ 290 |
| 2205 | ≥ 620 | ≥ 450 | ≥ 25 | ≤ 290 |
| 2507 | ≥ 730 | ≥ 550 | ≥ 20 | ≤ 310 |
Note: The values above are for reference only. Please refer to the mill test certificate for actual data.
| Chemical Environment | 304/316 | 2304 | 2205 | 2507 |
|---|---|---|---|---|
| Acetic Acid (up to 100%) | Good | Good | Excellent | Excellent |
| Citric Acid | Good | Good | Excellent | Excellent |
| Formic Acid (up to 50%) | Poor | Fair | Good | Good |
| Lactic Acid | Good | Good | Excellent | Excellent |
| Nitric Acid (up to 65%) | Good | Good | Good | Good |
| Phosphoric Acid (up to 85%) | Fair | Good | Excellent | Excellent |
| Sulfuric Acid (dilute) | Poor | Poor | Fair | Good |
| Sulfuric Acid (concentrated) | Poor | Poor | Poor | Fair |
| Caustic Soda (NaOH) | Good | Good | Good | Good |
| Chlorides / Brine | Poor | Fair | Good | Excellent |
| Organic Solvents | Excellent | Excellent | Excellent | Excellent |
| Seawater / Brackish Water | Poor | Fair | Good | Excellent |
Stress Corrosion Cracking Resistance – Ferrite phase stops SCC propagation in chloride environments
High Pitting Resistance – PREN of 25-45 protects against localized attack
High Strength – Allows for thinner wall sections, reducing weight and cost
Good Weldability – Can be fabricated into complex piping systems
Wide Temperature Range – Suitable for cryogenic to elevated temperatures
Low Carbon Content – Prevents intergranular corrosion after welding
ASME B31.3 Compliant – Suitable for process piping
| Grade | PREN | Recommended Chemical Service |
|---|---|---|
| 2304 | 24 – 26 | Mild acids, food processing, clean chemicals |
| 2205 | 33 – 35 | Organic acids, phosphoric acid, chloride-containing streams |
| 2507 | ≥ 41 | Sulfuric acid (dilute), high chloride acids, severe environments |
| Application | Recommended Grade | Reason |
|---|---|---|
| Organic Acid Transfer Lines | 2205 | Resists acetic, formic, and lactic acids |
| Phosphoric Acid Piping | 2205 | Excellent resistance to wet process phosphoric acid |
| Chloride-Containing Process Streams | 2205 or 2507 | SCC and pitting protection |
| Heat Exchanger Tubing | 2205 | High strength allows thinner walls, better heat transfer |
| Caustic Service Lines | 2304 or 2205 | Good resistance to sodium hydroxide |
| Solvent Recovery Systems | 2304 | Cost effective for non-corrosive organics |
| Brine / Salt Processing | 2507 | Superior chloride pitting resistance |
| Fertilizer Plant Piping | 2205 | Phosphoric and sulfuric acid resistance |
| Amine Service (CO₂ / H₂S removal) | 2205 (NACE) | Sour service certified |
| Distillation Column Feed Lines | 2205 | High temperature strength and corrosion resistance |
| Grade | Minimum Temperature | Maximum Continuous | Maximum Intermittent |
|---|---|---|---|
| 2304 | -40°C (-40°F) | 250°C (482°F) | 280°C (536°F) |
| 2205 | -50°C (-58°F) | 280°C (536°F) | 300°C (572°F) |
| 2507 | -50°C (-58°F) | 280°C (536°F) | 300°C (572°F) |
Avoid prolonged exposure above 300°C as this can cause embrittlement of the ferrite phase.
| Requirement | Duplex Pipe Compliance |
|---|---|
| ASME B31.3 Process Piping | Yes |
| Pressure Design | Higher allowable stress than austenitic (up to 2x) |
| Wall Thickness Reduction | 30-50% thinner than 304/316 for same pressure |
| Corrosion Allowance | Minimal or none required |
| Flange Ratings | Compatible with standard ASME flanges |
| Gasket Selection | PTFE, spiral wound, graphite (avoid chlorides) |
| Process | Recommendation |
|---|---|
| Welding | Use matching filler metal (2209 for 2205). Back purge with argon. Control interpass temperature below 150°C. |
| Bending | Cold bending preferred. Minimum radius 3x OD for seamless, 4x OD for welded. |
| Heat Treatment | Solution anneal at 1040-1100°C after significant cold work. |
| Pickling / Passivation | Required after welding to restore corrosion resistance. Use nitric-hydrofluoric acid blend. |
| Flange Joint Assembly | Use controlled torque. Avoid galvanized or low alloy bolting. |
| Hydrotesting | Use clean fresh water with ≤ 50 ppm chlorides. Dry thoroughly after testing. |
Planning a chemical plant project? We can supply the right duplex pipe for your process conditions.
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