ASTM A234 WP11 Pipe Fittings are alloy steel buttweld fitting products made from 2.25 CHEVY and 3.5 CHEVY carbon steel and chromium-molybdenum steel pipe fittings for moderate and high temperature pressure piping applications. The WP11 grade is resistant to oxidation, has reliable strength and good thermal stability and is suitable for high demanding industrial environments. The fittings come in seamless or welded varieties, such as elbows, tees, reducers, caps and bends, offering flexibility in piping system design. They are made with a consistent performance and durability to ASTM A234 and ASME standards. The Metinox Overseas range of ASTM A234 WP11 Pipe Fittings are supplied in a variety of classes and configurations to assure precision, quality and delivery on time to satisfy the needs of critical industrial applications.
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- Specifications of ASTM A234 WP11 Pipe Fittings
- Chemical Composition of ASTM A234 WP11 Pipe Fittings (Class Wise)
- Mechanical Properties of ASTM A234 WP11 Pipe Fittings
- ASTM A234 WP11 Class 1, Class 2 and Class 3 Difference
- Types of ASTM A234 WP11 Pipe Fittings
- Dimension Chart for ASTM A234 WP11 Pipe Fittings
- Weight Chart of ASTM A234 WP11 Pipe Fittings
- ASTM A234 WP11 Pipe Fittings Pressure Rating Chart
- ASTM A234 WP11 vs WP22 Pipe Fittings
- Heat Treatment, PWHT and Weld Inspection for WP11 Fittings
- Applications and Industrial Uses of ASTM A234 WP11 Pipe Fittings
- Related Products
- Frequently Asked Questions
Specifications of ASTM A234 WP11 Pipe Fittings
| Parameter | Details |
|---|---|
| Specification | ASTM A234 / ASME SA234 |
| Material Type | Chromium-Molybdenum Alloy Steel |
| Grade | WP11 (1.25Cr – 0.5Mo) |
| Product Type | Buttweld Pipe Fittings |
| Manufacturing Process | Wrought (Seamless / Welded) |
| Available Classes | Class 1, Class 2, Class 3 |
| Temperature Range | Moderate to High Temperature Applications |
| Applicable Standards | ASME B16.9, ASME B16.28, MSS-SP-75 |
| Fitting Types | Elbows, Tees, Reducers, Caps, Stub Ends, Bends |
| Construction Type | Seamless and Welded |
| Application | Pressure Piping Systems |
| Key Properties | Good strength, heat resistance, and oxidation resistance |
| Brand | Metinox Overseas |
Chemical Composition of ASTM A234 WP11 Pipe Fittings (Class Wise)
| Element | WP11 Class 1 (%) | WP11 Class 2 / Class 3 (%) |
|---|---|---|
| Carbon (C) | 0.05 – 0.15 | 0.05 – 0.20 |
| Manganese (Mn) | 0.30 – 0.60 | 0.30 – 0.80 |
| Phosphorus (P) | Max 0.030 | Max 0.040 |
| Sulfur (S) | Max 0.030 | Max 0.040 |
| Silicon (Si) | 0.50 – 1.00 | 0.50 – 1.00 |
| Chromium (Cr) | 1.00 – 1.50 | 1.00 – 1.50 |
| Molybdenum (Mo) | 0.44 – 0.65 | 0.44 – 0.65 |
Mechanical Properties of ASTM A234 WP11 Pipe Fittings
| Grade | Tensile Strength (Mpa) | Yield Strength (Mpa) | Elongation % |
|---|---|---|---|
| A234 WP11 | 415 - 585 | ≥205 | ≥20 |
ASTM A234 WP11 Class 1, Class 2 and Class 3 Difference
| Parameter | Class 1 | Class 2 | Class 3 |
|---|---|---|---|
| Application Level | Standard applications | Higher strength requirement | Critical/high-strength applications |
| Minimum Tensile Strength | 60–85 ksi | ≥ 70 ksi | Higher than Class 2 (as specified) |
| Minimum Yield Strength | Standard | ≥ 40 ksi | Higher than Class 2 |
| Mechanical Properties | Basic requirements | Improved strength | Enhanced strength for demanding conditions |
| Usage | General piping systems | Moderate to high-pressure systems | Only when specified in project requirements |
| Selection Criteria | Default choice | When higher strength is needed | Must be explicitly specified |
| Purchase Order Requirement | Must specify Class 1 | Must specify Class 2 | Must specify Class 3 |
| Other PO Details | - | - | Must include fitting type, size, schedule, construction, and inspection requirements |
Types of ASTM A234 WP11 Pipe Fittings
90° Elbow
45° Elbow
Equal Tee
Reducing Tee
Concentric Reducer
Eccentric Reducer
Pipe Cap
Pipe Bend
Stub End
Dimension Chart for ASTM A234 WP11 Pipe Fittings
| NPS (inch) | O.D. (mm) | O.D. (inches) | 90° LR Elbow: Center to Face (Inches) | 90° SR Elbow: Center to Face (Inches) | 45° LR Elbow: Center to Face (Inches) | 45° LR Elbow: Radius (Inches) | 180° Return Elbow: Center to Center (Inches) | 180° Return Elbow: Back to Face (Inches) |
|---|---|---|---|---|---|---|---|---|
| 1/2 | 21.3 | 0.840 | 1 1/2 | – | 5/8 | 2 | 1 7/8 | |
| 3/4 | 26.7 | 1.050 | 1 1/8 | – | 7/16 | 2 1/4 | 1 11/16 | |
| 1 | 33.4 | 1.315 | 1 1/2 | 1 | 7/8 | 3 | 2 3/16 | |
| 1 1/4 | 42.2 | 1.660 | 1 7/8 | 1 1/4 | 1 | 3 3/4 | 2 3/4 | |
| 1 1/2 | 48.3 | 1.900 | 2 1/4 | 1 1/2 | 1 1/8 | 3 | 4 1/2 | 3 1/4 |
| 2 | 60.3 | 2.375 | 3 | 2 | 1 3/8 | 4 | 6 | 4 3/16 |
| 2 1/2 | 73.0 | 2.875 | 3 3/4 | 2 1/2 | 1 3/4 | 5 | 7 1/2 | 5 3/16 |
| 3 | 88.9 | 3.500 | 4 1/2 | 3 | 2 | 6 | 9 | 6 1/4 |
| 3 1/2 | 101.6 | 4.000 | 5 1/4 | 3 1/2 | 2 1/4 | 7 | 10 1/2 | 7 1/4 |
| 4 | 114.3 | 4.500 | 6 | 4 | 2 1/2 | 8 | 12 | 8 1/4 |
| 5 | 141.3 | 5.563 | 7 1/2 | 5 | 3 1/8 | 10 | 15 | 10 5/16 |
| 6 | 168.3 | 6.625 | 9 | 6 | 3 3/4 | 12 | 18 | 12 5/16 |
| 8 | 219.1 | 8.625 | 12 | 8 | 5 | 12 | 24 | 16 5/16 |
| 10 | 273.1 | 10.750 | 15 | 10 | 6 1/4 | 15 | 30 | 20 3/8 |
| 12 | 323.9 | 12.750 | 18 | 12 | 7 1/2 | 18 | 36 | 24 3/8 |
Weight Chart of ASTM A234 WP11 Pipe Fittings
| DN | Sch 10S: 90° Elbow | Sch 10S: 45° Elbow | Sch 10S: Equal Tee | Sch 40S: 90° Elbow | Sch 40S: 45° Elbow | Sch 40S: Equal Tee | Sch 80S: 90° Elbow | Sch 80S: 45° Elbow | Sch 80S: Equal Tee |
|---|---|---|---|---|---|---|---|---|---|
| 8 | 0.02 | 0.01 | 0.03 | 0.03 | 0.02 | 0.06 | 0.04 | 0.03 | 0.07 |
| 10 | 0.03 | 0.02 | 0.05 | 0.03 | 0.02 | 0.03 | 0.06 | 0.04 | 0.09 |
| 15 | 0.06 | 0.03 | 0.09 | 0.08 | 0.04 | 0.10 | 0.10 | 0.05 | 0.14 |
| 20 | 0.07 | 0.03 | 0.13 | 0.08 | 0.04 | 0.17 | 0.11 | 0.05 | 0.20 |
| 25 | 0.14 | 0.08 | 0.28 | 0.15 | 0.11 | 0.29 | 0.22 | 0.14 | 0.38 |
| 32 | 0.23 | 0.11 | 0.49 | 0.26 | 0.17 | 0.59 | 0.40 | 0.23 | 0.68 |
| 40 | 0.30 | 0.17 | 0.68 | 0.40 | 0.23 | 0.86 | 0.51 | 0.29 | 1.02 |
| 50 | 0.50 | 0.25 | 0.85 | 0.70 | 0.40 | 1.28 | 0.91 | 0.59 | 1.59 |
| 65 | 0.85 | 0.48 | 1.41 | 1.40 | 0.77 | 2.19 | 1.81 | 0.99 | 3.13 |
| 80 | 1.25 | 0.63 | 1.77 | 2.20 | 1.08 | 3.31 | 2.97 | 1.50 | 4.45 |
| 90 | 1.70 | 0.75 | 2.67 | 2.83 | 1.42 | 4.08 | 4.00 | 2.00 | 5.44 |
| 100 | 2.10 | 1.08 | 3.46 | 4.47 | 2.09 | 5.27 | 6.18 | 2.81 | 7.71 |
| 150 | 5.45 | 2.72 | 8.07 | 10.89 | 5.44 | 10.99 | 16.32 | 8.16 | 13.61 |
| 200 | 10.20 | 5.33 | 15.65 | 21.54 | 10.77 | 20.91 | 33.11 | 16.56 | 28.12 |
| 250 | 18.15 | 9.75 | 26.46 | 38.56 | 19.27 | 35.38 | 51.71 | 25.86 | 49.90 |
| 300 | 25.80 | 13.62 | 39.46 | 59.42 | 29.71 | 62.14 | 79.38 | 39.69 | 83.91 |
ASTM A234 WP11 Pipe Fittings Pressure Rating Chart
| Temperature Ratings (°F) | Temperature Ratings (°C) | Pressure Class: 150 | Pressure Class: 300 (1/4 - 1 Inches) | Pressure Class: 300 (1 1/4 - 2 Inches) | Pressure Class: 300 (2 1/2 - 3 Inches) |
|---|---|---|---|---|---|
| -20 to 150 | -29 to 66 | 300 | 2000 | 1500 | 1000 |
| 200 | 93 | 265 | 1785 | 1350 | 910 |
| 250 | 121 | 225 | 1575 | 1200 | 825 |
| 300 | 149 | 185 | 1360 | 1050 | 735 |
| 350 | 177 | 150 | 1150 | 900 | 650 |
| 400 | 204 | - | 935 | 750 | 560 |
| 450 | 232 | - | 725 | 600 | 475 |
| 500 | 260 | - | 510 | 450 | 385 |
| 550 | 288 | - | 300 | 300 | 300 |
ASTM A234 WP11 vs WP22 Pipe Fittings
| Parameter | WP11 | WP22 | Selection Note |
|---|---|---|---|
| Cr-Mo family | 1.25Cr-0.5Mo | 2.25Cr-1Mo | WP22 provides higher chromium and molybdenum for more severe temperature service. |
| Matching pipe | ASTM A335 P11 | ASTM A335 P22 | Match the fitting grade to the project pipe class. |
| Matching forged fitting / flange | ASTM A182 F11 | ASTM A182 F22 | Do not interchange without engineering approval. |
| Common use | Steam, boiler and refinery piping where 1.25Cr-0.5Mo is specified | Higher-temperature refinery and power service where 2.25Cr-1Mo is specified | Final selection depends on design pressure, temperature and piping material specification. |
Heat Treatment, PWHT and Weld Inspection for WP11 Fittings
ASTM A234 WP11 fittings are available in either full annealed, isothermal annealed or normalized and tempered. Any fusion-welded WP11 fittings after the above heat treatment shall have post-weld heat treatment to not less than the above temperature (1150°F / 620°C) unless otherwise specified in the applicable code or purchase specification. When requested, welds should be provided with EN 10204 3.1 or 3.2 qualified NDE records.
Applications and Industrial Uses of ASTM A234 WP11 Pipe Fittings
WP11 fittings are used in steam lines, boiler headers, superheater and reheater connections, refinery process piping, heat exchanger piping and Cr-Mo utility systems where the pipe class specifies 1.25Cr-0.5Mo alloy steel.
Frequently Asked Questions
ASTM A234 WP11 pipe fittings are chromium-molybdenum alloy steel fittings used in moderate to high-temperature pressure piping systems.
WP11 is equivalent to ASTM A335 P11 alloy steel, with similar chemical composition and properties.
Yes, WP11 fittings are suitable for moderate to high-pressure and high-temperature applications.
The UNS number for ASTM A234 WP11 is K11597.
Yes, WP11 fittings have good weldability and can be welded using proper procedures and heat treatment.
WP11 typically contains around 1.0% to 1.5% chromium, providing improved heat and corrosion resistance.
The difference lies in strength and chemistry limits—Class 1 is standard, Class 2 has higher strength, and Class 3 has the highest strength for critical applications.
Yes, WP11 fittings are typically normalized and tempered to achieve the required mechanical properties and performance.
WP11 fittings are commonly used with ASTM A335 P11 pipes and ASTM A182 F11 flanges for compatibility.
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