ASTM A234 WP91 Alloy Steel Elbow
ASTM A234 WP91 Alloy Steel Elbow is a butt weld pipe fitting manufactured in accordance with ASTM A234, ASME SA234 and ASME B16.9 for high-temperature and high-pressure piping systems.
Elbow
ASTM A234 WP91 Alloy Steel Elbow is a butt weld pipe fitting manufactured in accordance with ASTM A234, ASME SA234 and ASME B16.9 for high-temperature and high-pressure piping systems.
Product Overview
ASTM A234 WP91 Alloy Steel Elbow is a butt weld pipe fitting manufactured in accordance with ASTM A234, ASME SA234 and ASME B16.9 for high-temperature and high-pressure piping systems.
Manufactured from 9Cr-1Mo-V alloy steel, WP91 elbows provide excellent creep strength, oxidation resistance and long-term metallurgical stability for demanding service conditions.
Hongcheng supplies WP91 alloy steel elbows in the normalized and tempered condition, making them suitable for ultra-supercritical (USC) power plants, main steam piping systems, reheat systems, refinery process piping and other high-temperature industrial applications.
Material & Heat Treatment
ASTM A234 WP91 is based on the same 9Cr-1Mo-V alloy system as ASTM A335 P91 seamless pipe and ASTM A182 F91 forged flanges.
Its controlled chemical composition provides improved creep rupture strength, oxidation resistance and thermal stability compared with conventional 2.25Cr-1Mo alloy steels.
Key alloying elements include chromium (Cr), molybdenum (Mo), vanadium (V), niobium (Nb) and nitrogen (N), which are tightly controlled to ensure required creep strength and microstructure stability.
Heat treatment includes:
• Normalizing: 1040–1080°C
• Tempering: 730–780°C
This process produces a stable tempered martensitic microstructure suitable for long-term operation under elevated temperature and pressure.
Manufacturing Process
Steel Billet / Forging Stock → Heating → Hot Pressing or Push Bending → Sizing & Calibration → Normalizing & Tempering → UT & MT Inspection → Beveling → Marking → Packing
Dimensions & Standards
|
Item |
Specification |
|
Material Standard |
ASTM A234 / ASME SA234 |
|
Dimension Standard |
ASME B16.9 |
|
End Preparation |
ASME B16.25 |
|
Material Grade |
WP91 |
|
Manufacturing Method |
Seamless / Welded |
Technical Parameters
|
Parameter |
Value |
|
Grade |
ASTM A234 WP91 |
|
Product Type |
Alloy Steel Butt Weld Elbow |
|
Angle |
15°, 22.5°, 30°, 45°, 60°, 90°, 180° |
|
Outside Diameter |
1/2"–48" (DN15–DN1200) |
|
Wall Thickness |
SCH 10, SCH 20, SCH 40, SCH 80, SCH 160, XXS |
|
Bend Radius |
Long Radius (1.5D) / Short Radius (1D) |
|
Manufacturing Method |
Seamless / Welded |
|
Heat Treatment |
Normalized & Tempered |
|
End Type |
Beveled Ends (ASME B16.25) |
|
Surface |
Black Painted / Anti-rust Oil / Natural Finish |
Inspection & Testing
Every ASTM A234 WP91 alloy steel elbow is inspected throughout production to ensure compliance with ASTM A234 and ASME SA234 requirements.
Available inspection methods include:
EN 10204 Type 3.1 Material Test Certificates are available for every production batch.
Applications
ASTM A234 WP91 alloy steel elbows are widely used in:
• Ultra-supercritical (USC) power plant main steam systems
• Reheat steam piping
• Oil refineries
• Petrochemical plants
• Thermal power stations
• Combined cycle power plants
• Boiler headers and outlet manifolds
• Chemical processing facilities
• High-pressure steam distribution systems operating above 580°C
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Projects of Elbow
Power Plant Projects
Products: P91 Pipes · P92 Pipes · Pipe Fittings · Pipe Spools
FAQs
What is the difference between ASTM A234 WP91 and ASTM A335 P91?
ASTM A234 WP91 is the wrought fitting grade used for elbows, tees, reducers and caps, while ASTM A335 P91 is the seamless pipe grade.
Both are manufactured from the same 9Cr-1Mo-V alloy system and are heat treated in the normalized and tempered condition for use in the same high-temperature piping systems.
Does WP91 require post weld heat treatment (PWHT)?
Yes. Welded joints generally require preheating and post weld heat treatment in accordance with ASME B31.1 or ASME B31.3, together with qualified welding procedures (WPS/PQR).
What temperature can WP91 alloy steel elbows withstand?
WP91 alloy steel elbows are commonly used in high-temperature piping systems at operating temperatures of approximately 600–621°C, depending on the applicable design code, pressure, and operating conditions.
Can custom angles and bend radii be supplied?
Yes. Non-standard angles including 15°, 22.5°, 30° and 60°, as well as custom bend radii, can be manufactured according to customer drawings or project specifications.
What standards are available?
Products can be manufactured in accordance with:
• ASTM A234
• ASME SA234
• ASME B16.9
• ASME B16.25
What inspection documents are available?
EN 10204 Type 3.1 Material Test Certificates and project-specific inspection reports can be supplied upon request.
Wuliyao Industrial Zone, Yanshan County, Cangzhou City, Hebei Province, China.
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