Elbow
ASTM A234 WP22 Alloy Steel Elbow is a chromium-molybdenum alloy steel butt weld fitting manufactured in accordance with ASTM A234 / ASME SA234 and ASME B16.9 for high-temperature refinery and power plant service environments.
Product Overview
ASTM A234 WP22 Alloy Steel Elbow is a chromium-molybdenum alloy steel butt weld fitting manufactured in accordance with ASTM A234 / ASME SA234 and ASME B16.9 for high-temperature refinery and power plant service environments.
Based on a 2.25Cr-1Mo alloy system, WP22 alloy steel elbows provide a balanced combination of high-temperature strength, hydrogen attack resistance and weldability, making them one of the most widely used alloy steel grades in refinery and petrochemical applications.
WP22 is a proven, cost-effective alloy steel grade suitable for hydrogenation units, hydrocrackers, catalytic reformer systems and high-temperature process piping operating at temperatures up to approximately 565°C.
Hongcheng supplies ASTM A234 WP22 alloy steel elbows in normalized and tempered condition, with full material traceability, inspection documentation and project-specific technical support.
Material & Heat Treatment
ASTM A234 WP22 shares the same 2.25Cr-1Mo alloy system as ASTM A335 P22 seamless pipe and ASTM A182 F22 forgings, which are extensively applied in refinery, petrochemical and power generation industries.
Key alloying elements include:
Chromium (Cr)
Molybdenum (Mo)
Manganese (Mn)
Silicon (Si)
Carbon (C)
Chromium provides oxidation and sulfidation resistance, while molybdenum enhances high-temperature strength, creep resistance and hydrogen attack resistance.
Typical heat treatment includes:
Normalizing: 900–1000°C
Tempering: 675–775°C
This produces a stable tempered microstructure suitable for long-term operation in hydrogen-containing and high-temperature process environments.
Heat treatment parameters are controlled according to ASTM A234, ASME SA234, manufacturing procedures and customer project specifications.
Manufacturing Process
Steel Billet / Forging Stock → Heating → Hot Forming → Sizing & Calibration → Normalizing & Tempering → UT & MT Inspection → Beveling → Marking → Packing
Hongcheng applies strict manufacturing controls throughout forming, heat treatment and inspection processes to ensure dimensional accuracy, material integrity and consistent performance of every WP22 alloy steel elbow.
Technical Parameters
|
Parameter |
Value |
|
Grade |
ASTM A234 WP22 |
|
Product Type |
Alloy Steel Butt Weld Elbow |
|
Applicable Standards |
ASTM A234 / ASME SA234, ASME B16.9 |
|
Angle |
15°, 22.5°, 30°, 45°, 60°, 90°, 180° |
|
Outside Diameter |
1/2"–48" (DN15–DN1200) |
|
Wall Thickness |
SCH 40, SCH 80, SCH 160, XXS and Custom |
|
Bend Radius |
Long Radius (1.5D) / Short Radius (1D) |
|
Heat Treatment |
Normalized & Tempered |
|
End Type |
Beveled Ends (ASME B16.25) |
|
Surface |
Black Painted / Anti-rust Oil / Natural Finish |
|
Customization |
Custom Angles, Dimensions and Radii Available |
Inspection & Testing
Every ASTM A234 WP22 alloy steel elbow is inspected throughout production to ensure compliance with ASTM A234, ASME SA234, dimensional requirements and customer specifications.
Available inspections and testing include:
Welding Procedure Qualification (WPS / PQR) for welded assemblies
EN 10204 Type 3.1 Material Test Certificates (MTC) are available for each production batch.
Third-party inspection, additional non-destructive testing and project-specific documentation can be provided according to customer requirements.
Applications
ASTM A234 WP22 alloy steel elbows are widely used in:
• Hydrogenation units and hydrocrackers
• Catalytic reformer systems
• Refinery high-temperature process piping
• Subcritical power plant main steam piping
• Petrochemical reactor feed lines
• High-temperature heat exchanger piping
• Coal chemical process units
WP22 alloy steel elbows are selected for applications requiring a balanced combination of high-temperature strength, hydrogen attack resistance and weldability under elevated-temperature service conditions.
For hydrogen service applications, material selection and heat treatment should be confirmed according to API RP 941 (Nelson Curves) and applicable project specifications.
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Power Plant Projects
Products: P91 Pipes · P92 Pipes · Pipe Fittings · Pipe Spools
FAQs
What is the difference between WP22 and WP11?
WP22 and WP11 are both chromium-molybdenum alloy steel grades used for high-temperature refinery service.
WP22 is a 2.25Cr-1Mo alloy steel with higher chromium and molybdenum content, providing better high-temperature strength and hydrogen resistance compared with WP11 (1.25Cr-0.5Mo).
WP11 offers better weldability and cost-effectiveness for moderate-temperature and moderate-hydrogen service, while WP22 is selected for more demanding high-temperature and hydrogen-containing environments.
Does WP22 require PWHT?
Yes. Welded WP22 piping systems generally require preheating and post-weld heat treatment (PWHT) according to applicable construction codes, qualified welding procedures and project specifications.
What is the maximum service temperature of WP22?
WP22 is designed for high-temperature service and is commonly applied in systems operating up to approximately 565°C.
For hydrogen service, the allowable temperature and pressure conditions should be verified using API RP 941 (Nelson Curves).
Can custom angles and radii be supplied?
Yes. Hongcheng can manufacture custom WP22 alloy steel elbows according to customer drawings and technical specifications.
What standards are supported?
Products can be manufactured according to ASTM A234, ASME SA234, ASME B16.9 and ASME B16.25.
Wuliyao Industrial Zone, Yanshan County, Cangzhou City, Hebei Province, China.
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