Tubewell Steel & Engg. Co. is a leading manufacturer and stockist specializing in Alloy Steel Pipes, Tubes, Fittings and Flanges for critical industrial applications.
1.25% Chromium – 0.5% Molybdenum alloy steel buttweld fittings in Class 1, 2 and 3 for steam lines, boiler headers and refinery piping.
Tubewell Steel & Engg. Co. is a leading Mumbai manufacturer, stockist and supplier of ASTM A234 WP11 fittings – the most widely used chrome-moly fitting grade for moderate-temperature steam and process service. Our WP11 elbows, tees, reducers and caps are matched to A335 P11 pipe and available in Class 1, Class 2 and Class 3.
The workhorse chrome-moly fitting for steam and process piping
ASTM A234 WP11 is a wrought ferritic alloy steel fitting grade containing 1.00–1.50% chromium, 0.44–0.65% molybdenum and 0.50–1.00% silicon. Chromium and silicon improve oxidation resistance, while molybdenum raises creep and rupture strength at temperatures up to about 595°C (1100°F). WP11 offers an excellent balance of high-temperature strength, weldability and cost, which is why it is the most common fitting grade in power-plant steam lines, boiler headers and refinery heater piping.
The specification offers three strength classes: Class 1 (415 MPa min tensile), Class 2 (485 MPa) and Class 3 (520 MPa), allowing the fitting to match the pressure design of the connected pipe. We supply seamless and welded (WPW11) elbows, tees, reducers, caps and stub ends to ASME B16.9 / B16.28, annealed or normalized and tempered, with EN 10204 3.1 certificates, IBR documentation and third-party inspection on request.
Standard supply range for ASTM A234 WP11 fittings
| Parameter | Details |
|---|---|
| Standard | ASTM A234, ASME SA234 |
| Grade | WP11 Class 1, Class 2, Class 3 (UNS K11597); WPW11 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, IBR, NACE MR0175, TPI Reports |
International equivalents of A234 WP11
| Grade | ASTM / ASME | UNS | EN | W.Nr. | JIS | Matching Pipe / Forging |
|---|---|---|---|---|---|---|
| WP11 | A234 / SA234 WP11 | K11597 | 13CrMo4-5 | 1.7335 | STPA 23 | A335 P11 / A182 F11 |
Weight %, as per ASTM A234
| Grade | C | Mn | P | S | Si | Cr | Mo |
|---|---|---|---|---|---|---|---|
| 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 |
Values at room temperature as per ASTM A234
| Grade | Tensile Strength | Yield Strength (min) | Elongation (Long.) | Elongation (Trans.) | Hardness (max) |
|---|---|---|---|---|---|
| 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 |
Typical values (for reference)
| Property | Metric | Imperial |
|---|---|---|
| Density | 7.75 g/cm³ | 0.280 lb/in³ |
| Melting Range | 1450 – 1510 °C | 2640 – 2750 °F |
| Modulus of Elasticity | 205 GPa | 29.7 × 10³ ksi |
| Thermal Conductivity (100°C) | 37 W/m·K | 21.4 BTU/h·ft·°F |
| Mean Thermal Expansion (20–300°C) | 12.4 µm/m·°C | 6.9 µin/in·°F |
| Specific Heat | 0.46 J/g·°C | 0.11 BTU/lb·°F |
| Max. Service Temperature | ≈ 595 °C | ≈ 1100 °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 WP11 fittings are used
Main steam, hot reheat and auxiliary steam piping in thermal stations.
Boiler header connections, superheater and reheater links.
Heater outlet piping, hydrotreaters and catalytic reformers.
Hydrogen-bearing process lines at elevated temperature.
Ammonia and urea plant lines needing hydrogen-attack resistance.
HRSG and waste-heat boiler piping in cogeneration 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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