Tubewell Steel & Engg. Co. is a leading manufacturer and stockist specializing in Alloy Steel Pipes, Tubes, Fittings and Flanges for critical industrial applications.
Tubewell Steel & Engg. Co. is a Mumbai-based manufacturer, stockist and supplier of ASTM A234 alloy steel buttweld fittings. Our range of elbows, tees, reducers, caps, stub ends and return bends in grades WP5, WP9, WP11, WP22 and WP91 is built to match A335 pipes for steam, boiler, refinery and petrochemical service.
Chrome-moly buttweld fittings for elevated-temperature piping
Alloy steel buttweld fittings are wrought fittings made from seamless pipe, plate or forgings of chromium-molybdenum steel and covered by ASTM A234 / ASME SA234. The chromium in these grades – from 1.25% in WP11 up to 9% in WP9 and WP91 – improves resistance to oxidation, sulphidation and hydrogen attack, while molybdenum raises creep and rupture strength. This makes A234 fittings the natural partner for ASTM A335 P-grade pipes in power, refinery and petrochemical piping operating between roughly 400°C and 650°C.
We supply seamless (WP) and welded (WPW) fittings dimensioned to ASME B16.9, ASME B16.28 and MSS SP-43, in long and short radius, from 1/2" to 24" NB and schedules SCH 10 to XXS. Every fitting is heat treated as required by the specification, bevelled to ASME B16.25, marked per MSS SP-25 and shipped with EN 10204 3.1 mill test certificates. IBR documentation and third-party inspection by BV, TÜV, SGS, Lloyd's or EIL can be arranged on request.
Standard supply range for ASTM A234 alloy steel buttweld fittings
| Parameter | Details |
|---|---|
| Standard | ASTM A234, ASME SA234 |
| Grades | WP5 (Cl.1, Cl.3), WP9 (Cl.1, Cl.3), WP11 (Cl.1, Cl.2, Cl.3), WP22 (Cl.1, Cl.3), WP91 |
| Dimension Standard | ASME B16.9, ASME B16.28, MSS SP-43 |
| Size (NB) | Seamless: 1/2" NB to 24" NB; Welded (WPW): 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, Lateral |
| Manufacturing | Seamless (WP) and Welded (WPW) – hot formed / cold formed |
| Heat Treatment | Annealed or Normalized & Tempered; WP91: Normalized 1040–1080°C + Tempered 730–800°C |
| Ends | Bevelled Ends as per ASME B16.25 |
| Certificates | EN 10204 3.1 / 3.2, IBR, NACE MR0175, TPI Reports |
International equivalents of ASTM A234 alloy grades
| Grade | ASTM / ASME | UNS | EN | W.Nr. | JIS | Matching Pipe / Forging |
|---|---|---|---|---|---|---|
| WP5 | A234 / SA234 WP5 | K41545 | X11CrMo5 | 1.7362 | STPA 25 | A335 P5 / A182 F5 |
| WP9 | A234 / SA234 WP9 | K90941 | X11CrMo9-1 | 1.7386 | STPA 26 | A335 P9 / A182 F9 |
| WP11 | A234 / SA234 WP11 | K11597 | 13CrMo4-5 | 1.7335 | STPA 23 | A335 P11 / A182 F11 |
| WP22 | A234 / SA234 WP22 | K21590 | 10CrMo9-10 | 1.7380 | STPA 24 | A335 P22 / A182 F22 |
| WP91 | A234 / SA234 WP91 | K90901 | X10CrMoVNb9-1 | 1.4903 | STPA 28 | A335 P91 / A182 F91 |
Weight %, as per ASTM A234
| Grade | C | Mn | P | S | Si | Cr | Mo | Others |
|---|---|---|---|---|---|---|---|---|
| WP5 | 0.15 max | 0.30 – 0.60 | 0.040 max | 0.030 max | 0.50 max | 4.0 – 6.0 | 0.44 – 0.65 | – |
| 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 | – |
| WP11 Cl.1 | 0.05 – 0.15 | 0.30 – 0.60 | 0.030 max | 0.030 max | 0.50 – 1.00 | 1.00 – 1.50 | 0.44 – 0.65 | – |
| WP11 Cl.2 / Cl.3 | 0.05 – 0.20 | 0.30 – 0.80 | 0.040 max | 0.040 max | 0.50 – 1.00 | 1.00 – 1.50 | 0.44 – 0.65 | – |
| WP22 Cl.1 / Cl.3 | 0.05 – 0.15 | 0.30 – 0.60 | 0.040 max | 0.040 max | 0.50 max | 1.90 – 2.60 | 0.87 – 1.13 | – |
| WP91 | 0.08 – 0.12 | 0.30 – 0.60 | 0.020 max | 0.010 max | 0.20 – 0.50 | 8.0 – 9.5 | 0.85 – 1.05 | Ni 0.40 max, V 0.18–0.25, Nb 0.06–0.10, N 0.03–0.07, Al 0.02 max |
Values at room temperature as per ASTM A234
| Grade | Tensile Strength | Yield Strength (min) | Elongation (Long.) | Elongation (Trans.) | Hardness (max) |
|---|---|---|---|---|---|
| WP5 Cl.1 / WP9 Cl.1 | 415 – 585 MPa (60 – 85 ksi) | 205 MPa (30 ksi) | 30% | 20% | 217 HB |
| WP5 Cl.3 / WP9 Cl.3 | 485 – 655 MPa (70 – 95 ksi) | 275 MPa (40 ksi) | 22% | 14% | 217 HB |
| WP11 Cl.1 | 415 – 585 MPa (60 – 85 ksi) | 205 MPa (30 ksi) | 30% | 20% | 197 HB |
| WP11 Cl.2 | 485 – 655 MPa (70 – 95 ksi) | 275 MPa (40 ksi) | 22% | 14% | 197 HB |
| WP11 Cl.3 | 520 – 690 MPa (75 – 100 ksi) | 310 MPa (45 ksi) | 22% | 14% | 197 HB |
| WP22 Cl.1 | 415 – 585 MPa (60 – 85 ksi) | 205 MPa (30 ksi) | 30% | 20% | 197 HB |
| WP22 Cl.3 | 485 – 655 MPa (70 – 95 ksi) | 275 MPa (40 ksi) | 22% | 14% | 197 HB |
| WP91 | 620 – 840 MPa (90 – 120 ksi) | 415 MPa (60 ksi) | 20% | – | 248 HB |
Typical values (for reference)
| Property | WP5 | WP9 | WP11 | WP22 | WP91 |
|---|---|---|---|---|---|
| Density (g/cm³) | 7.70 | 7.67 | 7.75 | 7.80 | 7.77 |
| Modulus of Elasticity (GPa) | 205 | 205 | 205 | 205 | 218 |
| Thermal Conductivity, 100°C (W/m·K) | 33 | 26 | 37 | 36 | 26 |
| Mean Thermal Expansion, 20–300°C (µm/m·°C) | 11.9 | 11.5 | 12.4 | 12.6 | 11.4 |
| Specific Heat (J/g·°C) | 0.46 | 0.46 | 0.46 | 0.46 | 0.46 |
| Approx. Max. Service Temperature | ≈ 650 °C | ≈ 650 °C | ≈ 595 °C | ≈ 600 °C | ≈ 650 °C |
| ASME P-Number | 5B | 5B | 4 | 5A | 15E |
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 alloy steel buttweld fittings are used
Main steam, hot reheat and feedwater piping in thermal and supercritical units.
Fired heater transfer lines, hydrotreaters and crude/vacuum unit piping.
Crackers, reformers and hydrogen service lines at elevated temperature.
Header connections, superheater and reheater piping in boilers and HRSGs.
Ammonia and urea plant lines needing hydrogen-attack resistance.
High-pressure process and utility piping in onshore and offshore plants.
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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