ARK Stainless Inc is a trusted manufacturer, supplier and exporter of Duplex and Super Duplex Buttweld Fittings for high-pressure and corrosion-resistant piping systems used in offshore, marine, desalination, chemical processing, and oil & gas applications.
Our manufacturing range includes Duplex UNS S31803, S32205 and Super Duplex UNS S32750, S32760 Buttweld Elbows, Tees, Reducers, Caps, Stub Ends, and custom pipe fittings in seamless, welded, and fabricated construction.
These fittings are manufactured according to ASTM A815 / ASME SA815, ASME B16.9, ASME B16.28, and MSS SP-43 standards for industrial process piping systems requiring higher mechanical strength and improved resistance against pitting, crevice corrosion, and chloride exposure.
Duplex and Super Duplex Stainless Steel Buttweld Fittings are widely supplied for offshore platforms, seawater piping systems, refineries, chemical plants, heat exchangers, and process industries operating in corrosive environments.
Available in multiple schedules, wall thicknesses, and custom project requirements with inspection and material test certificate support.
| Grade | Common Name | C% | Mn% | Si% | P% | S% | Cr% | Ni% | Mo% | N% | Others |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2205 | S31803 | 0.030 | 2.00 | 1.00 | 0.030 | 0.020 | 21.0–23.0 | 4.5–6.5 | 2.5–3.5 | 0.08–0.20 | - |
| S32205 | 0.030 | 2.00 | 1.00 | 0.030 | 0.020 | 22.0–23.0 | 4.5–6.5 | 3.0–3.5 | 0.14–0.20 | - | |
| Super Duplex | S32750 / S32760 | 0.020 | - | - | - | 0.001 | 25 | 7 | 4.0 | 0.27 | - |
| Property | Duplex Steel (S31803/S32205) | Super Duplex Steel (S32750/S32760) |
|---|---|---|
| Tensile Strength | 90 ksi min | 116 ksi min |
| Yield Strength (0.2% Offset) | 65 ksi min | 80 ksi min |
| Yield Strength (0.1% Offset) | - | 91 ksi min |
| Elongation (%) | 25% min | 15% min |
| Hardness | HRC 293 max | Rockwell C 32 max |
| Impact Energy | - | 74 ft.-lbs. min |
Duplex Steel S31803 and S32205 Buttweld Fittings are widely supplied for offshore piping, seawater systems, chemical processing plants, heat exchangers, oil & gas installations, desalination units, and industrial process piping applications requiring higher strength and corrosion resistance.
ARK Stainless Inc manufactures,supplies and exports Duplex Steel Buttweld Elbows, Tees, Reducers, Caps, and Stub Ends in seamless and welded construction according to ASTM A815 and ASME B16.9 standards.
These fittings are commonly used in chloride-rich environments where resistance against pitting, crevice corrosion, and stress corrosion cracking is required.
All Duplex Steel Buttweld Fittings are supplied with material test certificates and inspection support as per project requirements. Testing includes PMI testing, hardness testing, chemical analysis, mechanical testing, flattening tests, IGC testing, and radiographic inspection.
| STANDARD | UNS | WNR. |
|---|---|---|
| Duplex Steel 2205 | S31803 / S32205 | 1.4462 |
Super Duplex S32750 and S32760 Buttweld Fittings are widely used in offshore piping systems, seawater applications, chemical processing plants, desalination units, oil & gas installations, and high-pressure industrial process piping systems requiring higher mechanical strength and corrosion resistance.
ARK Stainless Inc manufactures, supplies and exports Super Duplex Buttweld Elbows, Tees, Reducers, Caps, and Stub Ends in seamless and welded construction according to ASTM A815 and ASME B16.9 standards.
These fittings are commonly selected for chloride-rich and corrosive environments where improved resistance against pitting, crevice corrosion, and stress corrosion cracking is required.
All Super Duplex Steel Buttweld Fittings are supplied with material test certificates, PMI testing, hardness testing, chemical analysis, flattening tests, and third-party inspection support as per project requirements.
| STANDARD | UNS | WNR. |
|---|---|---|
| Super Duplex Steel 2507 | S32760 / S32750 | 1.4410 |
