Tubewell Steel & Engg. Co. is a leading manufacturer and stockist specializing in Alloy Steel Pipes, Tubes, Fittings and Flanges for critical industrial applications.
9% Chromium – 1% Molybdenum alloy steel buttweld fittings offering outstanding oxidation and sulphidation resistance for severe refinery and furnace service.
Tubewell Steel & Engg. Co. is a Mumbai manufacturer, stockist and supplier of ASTM A234 WP9 fittings – a 9Cr-1Mo ferritic alloy grade with the highest oxidation and sulphidation resistance among conventional chrome-moly steels. WP9 elbows, tees, reducers and caps are the matching fittings for A335 P9 pipe in refinery furnace and hot hydrocarbon service.
A high-chromium fitting grade for the most aggressive hot service
ASTM A234 WP9 is a wrought ferritic alloy steel fitting grade with 8.0–10.0% chromium and 0.90–1.10% molybdenum. The 9% chromium level forms a dense, protective oxide that resists scaling, high-temperature sulphidation and naphthenic acid attack far better than lower-chrome grades, while the 1% molybdenum maintains useful creep strength. WP9 is widely used in refinery heater coils, crude and vacuum transfer lines and other sulphur-rich, high-temperature environments.
We supply WP9 fittings in Class 1 and Class 3, annealed or normalized and tempered, as seamless and welded (WPW) elbows, tees, reducers, caps and stub ends. All fittings conform to ASME B16.9 / B16.28 dimensions, are bevelled per ASME B16.25, and come with EN 10204 3.1 certificates and complete heat traceability. 3.2 certification and third-party inspection are available on request.
Standard supply range for ASTM A234 WP9 fittings
| Parameter | Details |
|---|---|
| Standard | ASTM A234, ASME SA234 |
| Grade | WP9 Class 1, WP9 Class 3 (UNS K90941); WPW9 for welded |
| Dimension Standard | ASME B16.9, ASME B16.28, MSS SP-43 |
| Size (NB) | Seamless: 1/2" NB to 24" NB; Welded: 2" NB to 48" NB |
| Wall Thickness | SCH 10, 20, 40, STD, 60, 80, XS, 100, 120, 140, 160, XXS |
| Elbows | 45°, 90° and 180° – Long Radius (1.5D) and Short Radius (1D) |
| Bending Radius | R = 1D, 1.5D, 2D, 3D, 5D and custom pipe bends |
| Tees & Crosses | Equal Tee, Reducing Tee, Equal Cross, Reducing Cross |
| Reducers | Concentric Reducer, Eccentric Reducer |
| Other Types | Pipe Cap, Stub End (Long / Short pattern), Return Bend |
| Manufacturing | Seamless (WP) and Welded (WPW) – hot formed / cold formed |
| Heat Treatment | Full / Isothermal Annealed or Normalized & Tempered |
| Ends | Bevelled Ends as per ASME B16.25 |
| Certificates | EN 10204 3.1 / 3.2, NACE MR0175, TPI Reports |
International equivalents of A234 WP9
| Grade | ASTM / ASME | UNS | EN | W.Nr. | JIS | Matching Pipe / Forging |
|---|---|---|---|---|---|---|
| WP9 | A234 / SA234 WP9 | K90941 | X11CrMo9-1 | 1.7386 | STPA 26 | A335 P9 / A182 F9 |
Weight %, as per ASTM A234
| Grade | C | Mn | P | S | Si | Cr | Mo |
|---|---|---|---|---|---|---|---|
| A234 WP9 | 0.15 max | 0.30 – 0.60 | 0.030 max | 0.030 max | 1.00 max | 8.0 – 10.0 | 0.90 – 1.10 |
Values at room temperature as per ASTM A234
| Grade | Tensile Strength | Yield Strength (min) | Elongation (Long.) | Elongation (Trans.) | Hardness (max) |
|---|---|---|---|---|---|
| WP9 Cl.1 | 415 – 585 MPa (60 – 85 ksi) | 205 MPa (30 ksi) | 30% | 20% | 217 HB |
| WP9 Cl.3 | 485 – 655 MPa (70 – 95 ksi) | 275 MPa (40 ksi) | 22% | 14% | 217 HB |
Typical values (for reference)
| Property | Metric | Imperial |
|---|---|---|
| Density | 7.67 g/cm³ | 0.277 lb/in³ |
| Melting Range | 1450 – 1510 °C | 2640 – 2750 °F |
| Modulus of Elasticity | 205 GPa | 29.7 × 10³ ksi |
| Thermal Conductivity (100°C) | 26 W/m·K | 15.0 BTU/h·ft·°F |
| Mean Thermal Expansion (20–300°C) | 11.5 µm/m·°C | 6.4 µin/in·°F |
| Specific Heat | 0.46 J/g·°C | 0.11 BTU/lb·°F |
| Max. Service Temperature | ≈ 650 °C | ≈ 1200 °F |
As per ASME B16.9 – center-to-end / end-to-end dimensions in mm
| NPS | OD at Bevel | 90° LR Elbow (A) | 45° LR Elbow (B) | Tee (C / M) | 180° LR Return (O) | Cap (E) | Reducer (H) |
|---|---|---|---|---|---|---|---|
| 1/2" | 21.3 | 38 | 16 | 25 | 76 | 25 | – |
| 3/4" | 26.7 | 38 | 19 | 29 | 76 | 25 | 38 |
| 1" | 33.4 | 38 | 22 | 38 | 76 | 38 | 51 |
| 1 1/4" | 42.2 | 48 | 25 | 48 | 95 | 38 | 51 |
| 1 1/2" | 48.3 | 57 | 29 | 57 | 114 | 38 | 64 |
| 2" | 60.3 | 76 | 35 | 64 | 152 | 38 | 76 |
| 2 1/2" | 73.0 | 95 | 44 | 76 | 190 | 38 | 89 |
| 3" | 88.9 | 114 | 51 | 86 | 229 | 51 | 89 |
| 4" | 114.3 | 152 | 64 | 105 | 305 | 64 | 102 |
| 5" | 141.3 | 190 | 79 | 124 | 381 | 76 | 127 |
| 6" | 168.3 | 229 | 95 | 143 | 457 | 89 | 140 |
| 8" | 219.1 | 305 | 127 | 178 | 610 | 102 | 152 |
| 10" | 273.1 | 381 | 159 | 216 | 762 | 127 | 178 |
| 12" | 323.9 | 457 | 190 | 254 | 914 | 152 | 203 |
| 14" | 355.6 | 533 | 222 | 279 | 1067 | 165 | 330 |
| 16" | 406.4 | 610 | 254 | 305 | 1219 | 178 | 356 |
| 18" | 457.0 | 686 | 286 | 343 | 1372 | 203 | 381 |
| 20" | 508.0 | 762 | 318 | 381 | 1524 | 229 | 508 |
| 22" | 559.0 | 838 | 343 | 419 | – | 254 | 508 |
| 24" | 610.0 | 914 | 381 | 432 | 1829 | 267 | 508 |
All dimensions in mm. A, B, C/M = center-to-end; O = center-to-center; E = cap length (for standard wall); H = reducer end-to-end. Wall thickness is matched to the specified pipe schedule.
Where ASTM A234 WP9 fittings are used
Return bends and headers on refinery fired heater coils.
Transfer lines handling hot, sulphur and acid-bearing crude.
Delayed coker heater and drum feed piping at high temperature.
Cracker and reformer piping requiring strong scaling resistance.
Connection piping on high-temperature process exchangers.
Steam and superheater piping where oxidation resistance matters.
Quality you can verify on every heat
Large inventory for fast dispatch
MTC EN 10204 3.1 / 3.2
Positive material identification
Pan-India & export shipping
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