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| Brand Name: | Yuhong |
| Model Number: | ASTM A234 WP11-S 180 Degree U Bend |
| MOQ: | 1 PC |
| Price: | Negotiable |
| Payment Terms: | TT, LC |
| Supply Ability: | According to Clients' requirements |
ASTM A234 WP22-S 180 Degree Elbow/ Return Bend For Refinery Process Piping
An ASTM A234 WP22 180-Degree Elbow is a high-performance, alloy steel, U-turn pipe fitting used to change the direction of flow in high-temperature and high-pressure piping systems. Its specific material composition (Chrome-Moly) makes it strong, durable, and resistant to heat, oxidation, and creep, ensuring the safety and integrity of critical industrial infrastructure.
Here are some detailed breakdowns:
1. Chemical Composition (Heat Analysis) of ASTM A234 WP22
The chemical composition is the key factor that defines the WP22 grade. The values are percentages by weight.
| Element | Composition (%) | Notes |
| Carbon (C) | 0.05 - 0.15 | Provides strength. Controlled within a tight range for weldability. |
| Manganese (Mn) | 0.30 - 0.60 | Aids in strength and hardenability. |
| Phosphorus (P) | 0.025 max | Impurity, kept low to prevent brittleness. |
| Sulfur (S) | 0.025 max | Impurity, kept low to improve ductility and toughness. |
| Silicon (Si) | 0.50 max | Adds strength and improves oxidation resistance. |
| Chromium (Cr) | 2.00 - 2.50 | Key alloy. Provides high-temperature strength and oxidation/corrosion resistance. |
| Molybdenum (Mo) | 0.87 - 1.13 | Key alloy. Enhances strength and resistance to creep at high temperatures. |
Note: The material must also conform to the rules for product analysis tolerances as specified in the ASTM A234 specification.
2. Mechanical Properties of ASTM A234 WP22
These properties are the minimum required for the material after undergoing the appropriate heat treatment (normalize and temper, or anneal).
| Property | English Units | Metric Units | Notes |
| Tensile Strength | 60,000 psi (min) | 415 MPa (min) | The maximum stress the material can withstand while being stretched. |
| Yield Strength | 30,000 psi (min) | 205 MPa (min) | The stress at which the material begins to deform plastically. |
| Elongation | 20% (min) | 20% (min) | A measure of ductility. The amount of stretch before fracture. |
Important Notes on Mechanical Properties:
3. Key Characteristics and Manufacturing
4. Why This Specific Fitting is Chosen (The "Why")
The application is dictated by the synergy of its three features:
| Feature | Why It's Important for Application |
| 180-Degree Form (Return Bend) | • Creates a Compact Flow Reversal: Allows piping to double back on itself in tight spaces, like in boiler convection sections or heater coils. • Saves Space: A pre-fabricated elbow is more efficient than field-fitting two 90-degree elbows. • Improves Flow Efficiency: Provides a smoother, more consistent flow path than a sharp, fabricated turn, reducing turbulence and pressure drop. |
| WP22 Material (2.25 Chrome-1 Moly) | • High-Temperature Strength: Maintains structural integrity and pressure containment in services often exceeding 1000°F (538°C). • Creep Resistance: Withstands mechanical loads for extended periods at high temperatures without deforming (a phenomenon called "creep"). • Oxidation Resistance: The chromium content forms a stable oxide layer that protects the metal from scaling and corrosion in steam service. |
| ASTM A234 (Butt-Weld Fitting) | • Strong, Permanent Connection: Butt-welding creates a homogenous connection that is as strong as the pipe itself, essential for high-integrity systems. • Smooth Bore: Eliminates internal gaps or ridges that could cause erosion, turbulence, or corrosion. • Leak-Proof: Welded connections are ideal for hazardous and volatile process fluids. |
5. Common Applications
This fitting is used in demanding industrial environments where high temperature and pressure are present:
