Flange
Alloy Steel Flanges are forged fittings manufactured to ASTM A182 / ASME SA182, designed for high-temperature and high-pressure piping systems. Hongcheng manufactures and supplies alloy steel flanges in grades including F11, F22, F5 and F91, suitable for refinery process piping, power generation, hydrogenation units and petrochemical applications.
Product Overview
Alloy Steel Flanges are forged fittings manufactured to ASTM A182 / ASME SA182, designed for high-temperature and high-pressure piping systems. Hongcheng manufactures and supplies alloy steel flanges in grades including F11, F22, F5 and F91, suitable for refinery process piping, power generation, hydrogenation units and petrochemical applications.
These flanges are commonly used together with ASTM A335 alloy steel pipes and ASTM A234 alloy steel fittings of corresponding material grades. Each product form is governed by its respective ASTM / ASME material specification, while flanges provide the connection integrity required for elevated-temperature service conditions.
Hongcheng supplies alloy steel flanges with heat treatment performed in accordance with applicable material specifications and purchaser requirements. Full material traceability, inspection documentation and project-specific technical support are available. Custom sizes, facing types and drilling configurations can be supplied according to project drawings and specifications.
Flange Types
Alloy steel flanges are available in the following configurations:
• Weld Neck Flange (WN): Butt-welded to the pipe, suitable for high-stress and cyclic loading applications.
• Slip On Flange (SO): Pipe slips into the flange, easier alignment and lower cost for moderate services.
• Socket Weld Flange (SW): Pipe inserted into a recessed socket, suitable for small-bore, high-pressure piping.
• Blind Flange: Used to close the end of a piping system or vessel.
• Threaded Flange (TH): Internal threads allow connection without welding, generally used where welding is undesirable and where permitted by the applicable service and project specifications.
• Lap Joint Flange: Used with a stub end, allowing easy disassembly and alignment.
The selection of flange type depends on pressure rating, piping layout, maintenance requirements and project specifications.
Material & Heat Treatment
Alloy steel flanges are produced in chromium-molybdenum alloy grades including F11, F22, F5 and F91. Key alloying elements include Chromium (Cr), Molybdenum (Mo), Vanadium (V), Manganese (Mn), Silicon (Si) and Carbon (C) within the limits specified by the applicable material standard.
Chromium and molybdenum contribute to the material's elevated-temperature mechanical properties and resistance to oxidation in applicable service environments. Material suitability for hydrogen service depends on operating conditions, design requirements and applicable project specifications.
Typical heat-treatment requirements may include normalizing, tempering and other treatments specified by the applicable material grade and standard. Heat treatment parameters are controlled according to ASTM A182 / ASME SA182, qualified manufacturing procedures and purchaser requirements.
Manufacturing Process
Raw Material Inspection → Cutting → Forging → Heat Treatment → Machining → Dimensional Inspection → Surface Finishing → Marking → Final Inspection & Testing
Hot forging or other qualified forming processes may be used according to product size and configuration. Where welding is involved in attachments or special constructions, welding and applicable PWHT are performed according to qualified welding procedures and project requirements.
Technical Parameters
|
Parameter |
Specification |
|
Product |
Alloy Steel Flange |
|
Material Grades |
ASTM A182 F11 / F22 / F5 / F91 |
|
Manufacturing Standard |
ASTM A182 / ASME SA182 |
|
Flange Types |
Weld Neck (WN), Slip On (SO), Socket Weld (SW), Blind, Threaded, Lap Joint |
|
Size Range |
NPS 1/2–48 (DN15–DN1200), subject to applicable dimensional standards and manufacturing capability |
|
Pressure Rating |
Class 150 / 300 / 600 / 900 / 1500 / 2500, subject to size and applicable standard |
|
Facing Types |
Raised Face (RF), Ring Type Joint (RTJ), Flat Face (FF) |
|
Dimensional Standard |
ASME B16.5 / ASME B16.47, where applicable |
|
Heat Treatment |
According to applicable ASTM A182 / ASME SA182 requirements |
|
Surface |
Black Painted / Anti-Rust Oil / Natural Finish |
|
MTC |
EN 10204 3.1 available |
|
Customization |
Custom Drilling, Facing, Marking and Drawings Available |
Inspection & Testing
Inspection and testing are performed according to ASTM A182 / ASME SA182, applicable dimensional standards and purchaser requirements.
Available inspection and testing services may include:
EN 10204 Type 3.1 Material Test Certificates (MTC) can be provided according to purchase requirements. Third-party inspection, additional NDT and project-specific documentation are available upon request.
Applications
Alloy steel flanges are commonly used in:
• Refinery Process Piping
• Hydrogenation Units and Hydrocrackers
• Catalytic Reformer Systems
• Power Generation Piping Systems
• High-Temperature Steam Piping
• Boiler and Steam Piping Systems
• Petrochemical High-Temperature Reactors
• Hydrogen-Related Process Piping, subject to material compatibility and project requirements
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Projects of Flange
Power Plant Projects
Products: P91 Pipes · P92 Pipes · Pipe Fittings · Pipe Spools
FAQs
What is the difference between F11 and P11?
F11 and P11 refer to related grades within the same chromium-molybdenum alloy grade, but they are specified under different ASTM product standards. ASTM A335 P11 is used for seamless alloy steel pipe, while ASTM A182 F11 is used for forged alloy steel flanges. They may be specified together in high-temperature service, subject to the applicable piping design and material requirements.
How do I choose between weld neck and slip on flanges?
Weld neck flanges provide higher strength and fatigue resistance, making them suitable for high-pressure and high-temperature services. Slip on flanges are easier to install and more economical, typically used for moderate pressure and temperature conditions. The selection depends on operating conditions and project specifications.
What post-weld heat treatment is required for alloy steel flanges?
PWHT may be required depending on the applicable construction code, flange thickness, welding procedure and project requirements. Where welding is required, alloy steel flanges should be welded using qualified procedures with preheating and PWHT applied as required by the applicable code and project specifications.
Can custom drilling and facing be supplied?
Yes. Hongcheng can manufacture custom alloy steel flanges according to customer drawings and technical specifications, including custom drilling, facing, marking and special configurations.
What standards are supported?
Alloy steel flanges can be supplied according to ASTM A182 / ASME SA182, with dimensional requirements based on ASME B16.5 or ASME B16.47, where applicable. Weld-neck flange welding ends can be prepared according to ASME B16.25 where applicable.
Wuliyao Industrial Zone, Yanshan County, Cangzhou City, Hebei Province, China.
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