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Alloy Steel ASTM A234 WP22 Pipe Fittings
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At SteelPro Group, we provide precision-engineered WP22 steel fittings built to industry standards. This guide explores its characteristics, standards, and uses, helping you choose the best option for your needs.
What Is W22 Steel?
WP22 Steel is a high-temperature, high-pressure Chrome-Moly alloy steel. It provides exceptional durability, oxidation protection, and heat resistance. SteelPro Group WP22 pipe fittings are used in power plants, refineries, chemical processing, and boiler systems.
Cr enhances resistance to oxidation, while Mo increases strength and prevents deformation under prolonged stress. These properties allow WP22 Steel to withstand thermal stress and prolonged high temperatures without degradation. It is weldable and manufactured through forging, rolling, pressing, and welding, ensuring adaptability in industrial applications.
W22 Steel Pipe Fittings Standards
WP22 Steel complies with ASTM A234 WP22, a standard for alloy steel fittings used in high-temperature and high-pressure applications.
| Standard | Category |
| ASTM A234 / ASME SA234 | Pipe Fittings |
| ASTM A335 P22 / ASME SA335 P22 | Seamless Pipes |
| ASTM A691 2-1/4 Cr | Welded Pipes |
| ASTM A182 F22 | Flanges |
| ASTM A387 Grade 22 / ASME SA387 Grade 22 | Steel Plates |
| ASME B16.9 | Butt-Weld Fittings |
| ASME B16.11 | Socket-Weld & Threaded Fittings |
| MSS-SP-79, MSS-SP-83, MSS-SP-95, MSS-SP-97 | Design & Dimensional Standards |
W22 Steel Pipe Fittings Specification
SteelPro Group WP22 Steel is used in a variety of pipe fittings designed for high-temperature and high-pressure applications. These fittings are available in multiple sizes, thicknesses, and configurations to meet industrial requirements.
Available Pipe Fitting Types
- Elbows (Long Radius / Short Radius)
- Tees (Straight / Reducing)
- Reducers (Concentric / Eccentric)
- Caps, Crosses, Stub Ends
- Socket-Weld & Threaded Fittings
Size & Thickness Range
- Outer Diameter: ½” – 48” (ASME B16.9)
- Wall Thickness: SCH 10, SCH 20, SCH 30, STD, SCH 40, SCH 60, SCH 80, XS, SCH 100, SCH 120, SCH 140, SCH 160, XXS
- Pressure Ratings: Class 150 to Class 2500
W22 Steel Pipe Fittings Chemical Composition
| Element | Content (wt%) | Function |
| Carbon (C) | 0.05 – 0.15 | Increases strength and hardness |
| Manganese (Mn) | 0.3 – 0.6 | Enhances toughness and hardenability |
| Silicon (Si) | ≤ 0.50 | Improves oxidation resistance and strength |
| Sulfur (S) | ≤ 0.04 | Impurity, controlled to prevent brittleness |
| Phosphorus (P) | ≤ 0.04 | Impurity, controlled to avoid embrittlement |
| Chromium (Cr) | 2.00 – 2.50 | Enhances oxidation and corrosion resistance |
| Molybdenum (Mo) | 0.87 – 1.13 | Improves high-temperature strength and creep resistance |
W22 Steel Pipe Fittings Mechanical Properties
| Property | Value (Metric) | Value (Imperial) |
| Material Grade | WP22 | WP22 |
| Tensile Strength | 415 – 585 MPa | 60,191 – 84,847 psi |
| Yield Strength | ≥205 MPa | ≥29,732 psi |
| Elongation | ≥20% | ≥20% |
| Hardness | ≤197 HBW | ≤197 HBW |
W22 Steel Applications
WP22 steel is a Chrome-Moly alloy used in high-temperature, high-pressure environments.
- Power Plants & Boilers – Used in boilers, heat exchangers, and steam piping.
- Oil & Gas – Found in refineries, pipelines, and petrochemical processing.
- Chemical Plants – Applied in process piping, reactors, and pressure vessels.
- Nuclear Power – Used in steam generators and structural components.
- Pipelines – Supports steam, superheated water, and gas transport.
- Aerospace & Defense – Used in jet engines, pressure vessels, and structural parts.
- Other Industries – Found in automotive exhausts, cryogenics, and heavy machinery.
W22 Steel Pipe Fittings Heat Treatment
Annealing
This process increases flexibility, enhances workability, and relieves internal tension that may arise during shaping procedures. This process also helps refine the microstructure by softening the material.
- Heating Range: 1350 – 1450°F (730 – 790°C)
- Cooling Method: Controlled cooling in a furnace or air to prevent rapid temperature drops, which could lead to brittleness.
Normalizing
This process makes the material less brittle and more uniform.
- Heating Range: 1650 – 1750°F (900 – 955°C)
- Cooling Method: Air cooling to prevent excessive grain growth and ensure structural integrity.
Tempering
For WP22 Class 1 & Class 2, the most common practice is normalizing followed by tempering, as this provides an optimal balance of strength, ductility, and corrosion resistance.
- Heating Range: 1200 – 1350°F (650 – 730°C)
- Cooling Method: Air cooling after holding at the specified temperature.
Isothermal Annealing
Isothermal annealing is employed when consistent microstructure and mechanical properties are required, particularly for large or thick-walled pipe fittings. This process helps achieve better uniformity in hardness and improved machinability.
- Heating Range:1250 – 1350°F (675 – 730°C)
- Cooling Method: Holding the material at a controlled intermediate temperature before slow cooling.
Cooling Rate and Precautions
- WP22 steel fittings must not be water-quenched to prevent thermal shock and cracking.
- Cooling should be gradual, either by air cooling or controlled furnace cooling to avoid excessive hardness.
- If the fittings are cooled too quickly, the material may become brittle and susceptible to stress corrosion cracking (SCC).
Source Certified W22 Steel from SteelPro Group
At SteelPro Group, we provide high-quality WP22 Steel fittings that meet strict industry standards for strength, thermal stability, and long-term performance. Our fittings are crafted for accuracy, longevity, and effortless compatibility with industrial pipeline networks. Contact us today to find the right WP22 Steel solutions for your project.
