ASTM A815 WPS32750 Super Duplex 2507 Buttweld Pipe Fittings ASME B16.9 Equal Tee
This part is a wrought, seamless super duplex stainless steel equal tee made to ASTM A815 / ASME SA815 WPS32750 in grade UNS S32750 (2507, DIN 1.4410). It is formed from solution-annealed super duplex pipe or forging stock, re-annealed and water quenched to restore a balanced roughly 50/50 austenite-ferrite microstructure, then machined with bevel ends to ASME B16.25 and dimensioned to ASME B16.9. Finish is pickled and passivated, so the bore is clean, oxide free and ready for welding without further preparation.
Its job on site is simple but unforgiving: split or combine flow in a header that carries chlorides, and do it for twenty years without cracking. In a seawater cooling main, a ballast line or a chloride-rich process header, the failure point is rarely the pipe — it is the branch connection, where turbulent flow, residual weld stress and stagnant crevices meet. A 316L tee pits and stress-corrosion cracks in that service within a few years; a 2205 tee holds longer but still surrenders above roughly 40 °C chloride service. Grade 2507 removes that ceiling: PREN above 40, minimum 0.2% proof stress of 550 MPa, tensile range 800–965 MPa, and a critical pitting temperature that sits a full step above standard duplex.
Equivalent Grades of ASTM A815 UNS S32205 Super Duplex BW Pipe Fitting
| STANDARD |
WERKSTOFF NR. |
UNS |
| Super Duplex |
DIN 1.4410 |
S32750 |
ASTM A815 UNS S32205 Super Duplex BW Pipe Fitting Chemical Composition
| Chemical Element |
C |
Cr |
Mn |
Si |
P |
S |
Ni |
N |
Mo |
Cu |
Fe |
| % Present |
0.0 - 0.03 |
24.00 - 26.00 |
0.0 - 1.20 |
0.0 - 0.80 |
0.0 - 0.04 |
0.0 - 0.02 |
6.00 - 8.00 |
0.24 - 0.32 |
3.00 - 5.00 |
0.0 - 0.50 |
Balance |
ASTM A815 UNS S32205 Super Duplex BW Pipe Fitting Mechanical Properties
| Mechanical Property |
Proof Stress |
Tensile Strength |
Elongation A50 mm |
Hardness Brinell |
| Value |
550 Min MPa |
800-965 MPa |
15 Min % |
310 Max HB |
Note: 2507 is not a universal substitute. It is not recommended for strong reducing acids such as sulphuric acid without inhibitors, and continuous service above roughly 300 °C risks sigma-phase embrittlement. Tell us the medium, chloride level and temperature and we will confirm the grade before you commit the order.
ASTM A815 UNS S32205 Super Duplex BW Pipe Fitting Physical Properties
| Grades |
Density (g/cm 3) |
Density (lb/in 3) |
Melting Point (°C) |
Melting Point (°F) |
| UNS S32750 Pipe Fittings |
7.8 |
0.281 |
1350 |
2460 |
Standards & Certifications
ASTM A815 / ASME SA815 — product specification for wrought duplex and super duplex fittings.
ASME B16.9 — centre-to-end, outside diameter and wall tolerance for buttweld fittings.
ASME B16.25 — bevelled end preparation for welding.
NACE MR0175 / ISO 15156 — sour service qualification with hardness records.
ASTM A923 — detection of intermetallic phases in duplex grades (Practice A/B/C on request).
EN 10204 3.1 material test certificates as standard; 3.2 with third-party witness.
Works approvals and inspection experience with ISO, API, ABS, DNV, GL, LR and NK class requirements.
QA/QC & Certifications
Incoming material — mill certificate reviewed against the ASTM A815 heat analysis before release to production.
100% PMI — positive material identification on every tee, not lot sampling, to exclude grade mix-up.
Ferrite & hardness — ferritescope reading 35–65% and hardness within 310 HB, both recorded per heat.
Dimensional inspection — centre-to-end, OD, wall thickness and bevel angle checked to B16.9 / B16.25.
Pressure test — hydrostatic test at 1.5× design pressure with certificate.
Advanced NDT — PT, RT, UT and ASTM A923 intermetallic testing when specified.
Third-party inspection — SGS, BV, TUV, LR, DNV and client representatives are welcome at any stage; we schedule witness points to your ITP.
Records — full document package shipped with the goods and archived by heat number for later traceability.
Applications
1.The equal tee is normally specified wherever a high-chloride line needs a branch that will outlive the rest of the circuit:
2. Offshore oil & gas — subsea manifolds, topside process piping, produced-water and injection headers.
3. Seawater handling — cooling water circuits, desalination trains, ballast and fire-fighting mains.
4. Chemical & petrochemical — chloride-bearing acids, caustic and mixed process streams.
5. Pulp & paper — bleach plant and digester piping where 316L fails by pitting.
6. Flue gas desulfurization — absorber and slurry lines with high chloride and low pH.
7. Power generation — condenser water boxes, heat exchanger headers, high-pressure service loops.
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