ASTM A234 WP11-S 180 Degree U Bend For High Temperature And Pressure Application
Product Specifications
Product Name | 180 Degree Return Bend |
Specification | ASTM A234 |
Material | WP11-S |
Radius | LR or SR (Depend on Customer's Requirements) |
Surface | Black Painted or Oiled |
Test | Size Inspection, Visual Inspection, NDE Test |
Size Standard | ASME B16.9 |
Application | Heat Exchangers, Piping Systems, Oil and Gas Industry, Water Treatment |
Product Description
A 180-degree U-bend is a pipe fitting that curves back on itself in a semi-circular or U-shaped pattern, changing the flow direction by 180 degrees. It is commonly used in piping systems where space constraints or thermal expansion management require a tight directional reversal.
Key Features
- Shape & Geometry: Forms a complete half-circle (U-shape) with specified bend radius (R) as a multiple of pipe diameter
- Types: Short Radius (1D) for tight spaces, Long Radius (1.5D+) for smoother flow, or custom engineered radii
- Manufacturing: Hot induction bending for thick walls, cold bending for smaller pipes, or mandrel bending for smooth interiors
- Materials: Carbon steel, alloy steel (ASTM A234 WP11), stainless steel, or nickel alloys
- End Connections: Plain ends for welding, beveled ends for butt welding, or threaded ends for screw connections
Advantages vs. Two 90° Bends: Fewer welds reduce leak risks, lower pressure drop for smoother flow, and more compact design for tight spaces.
ASTM A234 WP11 Chemical Composition (%)
Element | WP11 Class 1 | WP11 Class 2 | WP11 Class 3 |
Carbon (C) | 0.05-0.15 | 0.05-0.20 | 0.05-0.20 |
Manganese (Mn) | 0.30-0.60 | 0.30-0.80 | 0.30-0.80 |
Phosphorus (P) | ≤ 0.030 | ≤ 0.030 | ≤ 0.030 |
Sulfur (S) | ≤ 0.030 | ≤ 0.030 | ≤ 0.030 |
Silicon (Si) | 0.50-1.00 | 0.50-1.00 | 0.50-1.00 |
Chromium (Cr) | 1.00-1.50 | 1.00-1.50 | 1.00-1.50 |
Molybdenum (Mo) | 0.44-0.65 | 0.44-0.65 | 0.44-0.65 |
Nickel (Ni) | ≤ 0.50 | ≤ 0.50 | ≤ 0.50 |
Vanadium (V) | - | - | ≤ 0.03 |
Columbium (Cb) | - | - | ≤ 0.08 |
ASTM A234 WP11 Mechanical Properties
Property | WP11 Class 1 | WP11 Class 2 | WP11 Class 3 |
Tensile Strength (MPa) | ≥ 415 | ≥ 485 | ≥ 485 |
Yield Strength (MPa) | ≥ 205 | ≥ 275 | ≥ 275 |
Elongation (%) (min) | 20 | 20 | 20 |
Hardness (HB) (max) | 197 | 197 | 197 |
Notes: WP11 Class 1 is standard grade, while Classes 2 & 3 offer higher strength through modified heat treatment (Class 3 includes micro-alloying elements). Suitable for high-temperature service up to 593°C (1100°F).
Applications
- Power Plants: Boiler systems, steam lines, and thermal expansion loops
- Oil & Gas Refineries: Crude oil processing and high-pressure gas lines
- Chemical Plants: Resistant to sulfur compounds and acidic/alkaline environments
- Steam Systems: Steam distribution networks up to 593°C
- Heating/Cooling: Heat recovery systems and condensers
