What Are Forged Flanges?

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What Are Forged Flanges?

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What Are Forged Flanges?

Forged flanges are components used in piping systems and pressure vessel connections to provide a secure and leak-free connection between pipes, valves, or other equipment. They are typically made by forging, which is a manufacturing process that involves shaping and compressing heated metal into the desired flange shape. Forged flanges are essential in various industries, including oil and gas, petrochemical, chemical, and power generation, where high-pressure and high-temperature conditions are common.

How Forged flanges are made?

Forged flanges are manufactured through a forging process, which involves shaping and compressing heated metal into the desired flange shape. The key steps in the manufacturing of forged flanges are as follows:

1. Material Selection: The process begins with the selection of the appropriate raw material, which is typically a metal or alloy. Common materials used for forged flanges include carbon steel, stainless steel, alloy steel, and other specialized materials. The choice of material depends on the specific application and the required properties, such as strength, corrosion resistance, and temperature resistance.

2. Heating: The selected material is heated to a high temperature in a furnace to make it malleable. The exact temperature and heating time depend on the material being used. Heating the metal makes it easier to shape and deform during the forging process.

3. Forging: Once the metal reaches the desired forging temperature, it is placed in a forging machine, which can be a hydraulic press, mechanical press, or hammer. The forging process involves applying extreme pressure to shape the heated metal into the required flange shape. The dies and tooling in the forging machine help create the specific design and dimensions of the flange.

4. Flashing and Trimming: During forging, excess material, known as flash, is forced out of the die cavities. After forging, the excess flash is removed, and the flange is trimmed to achieve the final dimensions and surface finish.

5. Heat Treatment: Forged flanges often undergo a heat treatment process, such as annealing or normalizing, to relieve any residual stresses and improve the material’s mechanical properties.

6. Machining: After the forging and heat treatment processes, the flanges may undergo further machining to refine the dimensions and achieve a smooth surface finish. This includes processes like turning, drilling, and threading.

7. Inspection and Testing: Quality control and inspection are critical at various stages of the manufacturing process. Forged flanges are inspected for dimensional accuracy, surface finish, and defects. They may also undergo various non-destructive and destructive testing methods, such as ultrasonic testing, radiographic testing, and pressure testing, to ensure their integrity and compliance with industry standards.

8. Marking and Identification: Forged flanges are typically marked with important information, including material specifications, size, pressure rating, and manufacturer’s markings, to ensure proper identification and traceability.

9. Surface Treatment: Depending on the material and application, the flanges may be subjected to additional surface treatments like painting, coating, or galvanizing to enhance corrosion resistance.

Once the forging process is complete and the flanges pass all quality checks, they are ready for packaging and shipping to be used in various industrial applications, where they play a crucial role in connecting pipes, valves, and other equipment in high-pressure and high-temperature environments.

Standards For Forged flanges:

Forged flanges are manufactured to adhere to various national and international standards to ensure their quality, safety, and compatibility in different applications. Some of the most commonly used standards for forged flanges include:

1. ASME B16.5: The American Society of Mechanical Engineers (ASME) B16.5 standard covers the dimensions, materials, and pressure-temperature ratings for pipe flanges and flanged fittings. It is widely used in the United States and other parts of the world and includes various types of flanges, such as weld neck, slip-on, socket weld, threaded, blind, and lap joint flanges.

2. ANSI B16.5: ANSI (American National Standards Institute) B16.5 is the same as ASME B16.5 and is used interchangeably. ANSI and ASME standards are often synonymous for many industrial applications.

3. ASTM A105: ASTM (American Society for Testing and Materials) A105 is a specification for carbon steel forgings used in various applications, including flanges, valves, and fittings.

4. ASTM A182: ASTM A182 covers a wide range of forged or rolled alloy and stainless steel pipe flanges, fittings, valves, and other components for high-temperature and high-pressure service. It includes materials like stainless steel, alloy steel, and duplex stainless steels.

5. EN 1092-1: This European standard covers flanges and their jointing faces and specifies various types and dimensions for flanges used in Europe and other regions that follow EN standards.

6. DIN 2501: The Deutsches Institut für Normung (DIN) standard 2501 is a German standard that specifies flange dimensions and materials. It is widely used in Europe.

7. JIS B2220: The Japanese Industrial Standards (JIS) B2220 standard outlines the dimensions, materials, and pressure ratings for steel pipe flanges used in Japan and other regions that adhere to JIS standards.

8. BS 4504: British Standard BS 4504 covers flanges for various applications and specifies flange dimensions and materials. It is commonly used in the United Kingdom and other regions that follow British standards.

9. MSS SP-44: The Manufacturers Standardization Society (MSS) SP-44 standard defines steel pipe flanges for pressure ratings between 150 and 2500. It includes materials, dimensions, and pressure-temperature ratings.

10. GOST 12821: The GOST (Gosudarstvennyy Standart) 12821 standard is a Russian standard that specifies the dimensions and materials for flanges used in Russia and some other countries within the former Soviet Union.

These are just a few examples of the many standards available for forged flanges. The choice of standard depends on the region in which the flanges will be used and the specific requirements of the application, such as pressure, temperature, and material compatibility. It’s essential to select the appropriate standard to ensure the flanges’ compliance with industry regulations and the safety and reliability of the overall piping system.

Types of forged flanges

Forged flanges come in various types, each designed for specific applications and requirements. The choice of flange type depends on factors such as the operating conditions, the type of connection needed, and the method of installation. Here are some common types of forged flanges:

1. Weld Neck Flange (WNRF – Weld Neck Raised Face):
– Weld neck flanges are used in high-pressure and high-temperature applications.
– They have a long neck that is welded to the pipe, providing reinforcement and reducing stress concentration.
– The raised face on the flange helps create a smooth and secure connection when bolted to another flange or equipment.

2. Slip-On Flange (SORF – Slip-On Raised Face):
– Slip-on flanges are easy to install and are used in low-pressure applications.
– They slide over the pipe and are then welded in place. The raised face provides a seal and bolt connection surface.

3. Socket Weld Flange (SWRF – Socket Weld Raised Face):
– Socket weld flanges are ideal for smaller-sized, high-pressure piping systems.
– They have a socket or opening for the pipe to fit into, and the connection is made through welding.
– The raised face helps create a tight seal when bolted to another flange or equipment.

4. Threaded Flange (THRF – Threaded Raised Face):
– Threaded flanges are used in low-pressure and low-temperature applications.
– They have internal threads to connect to threaded pipes or fittings.
– The raised face provides a sealing surface for a secure connection.

5. Blind Flange:
– Blind flanges are used to close the end of a piping system or vessel.
– They do not have an opening for the pipe, and their primary purpose is to block the flow or access to the system.
– They are often used for pressure testing or when future expansion is planned.

6. Lap Joint Flange (LJF):
– Lap joint flanges are used with stub ends in applications where frequent disassembly and assembly of the piping system are necessary.
– They have a flat face and a loose, slip-on fit with the stub end.
– The flange itself is not in contact with the fluid; it provides a convenient bolting point.

7. Orifice Flange:
– Orifice flanges are designed for metering orifice plate assemblies used in flow measurement applications.
– They have a specific bore size to accommodate orifice plates.

8. Ring Type Joint Flange (RTJ):
– Ring type joint flanges are used in high-pressure and high-temperature applications.
– They feature a special ring groove and a metal ring gasket that provides a tight and reliable seal.

9. Reducing Flange:
– Reducing flanges are used when connecting pipes of different diameters.
– They have one end with a larger bore and the other with a smaller bore to accommodate the size transition.

10. Spectacle Blind Flange:
– Spectacle blind flanges are used in applications where the flow needs to be alternately blocked and opened.
– They consist of two metal discs with a handle for easy rotation to block or open the flow.

These are some of the common types of forged flanges. The choice of flange type depends on the specific requirements of the piping system, including pressure, temperature, and the method of connection or sealing needed.

Pressure Ratings and Size for forged flanges

Forged flanges come in various pressure ratings and sizes to accommodate different applications and operating conditions. The pressure rating of a flange is an indication of the maximum pressure that it can safely handle. The size of a flange refers to the diameter of the pipe or equipment it is designed to connect. Here’s an overview of pressure ratings and sizes for forged flanges:

Pressure Ratings (Class or Pressure-Pipe Schedule):

1. Class 150 (PN 20): These flanges are designed for relatively low-pressure applications. They are commonly used in industries where moderate pressures are involved, such as water supply systems.

2. Class 300 (PN 50): Flanges with a Class 300 rating are suitable for higher pressure applications. They are used in various industrial settings, including chemical and petrochemical industries.

3. Class 600 (PN 100): Class 600 flanges are used in applications with even higher pressure requirements, such as high-pressure steam systems and high-pressure gas pipelines.

4. Class 900 (PN 150): Flanges rated as Class 900 are intended for severe service conditions, including high-temperature and high-pressure applications.

5. Class 1500 (PN 250): These flanges are used in extremely high-pressure applications where safety and reliability are paramount, such as in the oil and gas industry.

6. Class 2500 (PN 420): Class 2500 flanges are designed for the most demanding high-pressure applications, including those in critical environments like power generation and offshore drilling.

Sizes:

Forged flanges come in various sizes to match the diameter of the pipes or equipment they will be connected to. Common flange sizes include:

1. 1/2 inch (15mm) to accommodate small-diameter pipes or equipment.

2. 3/4 inch (20mm) for slightly larger pipes or applications.

3. 1 inch (25mm), a standard size for a wide range of applications.

4. 2 inches (50mm), used in various industries for moderate to high-pressure applications.

5. 3 inches (80mm), commonly used in industrial systems with larger pipe diameters.

6. 4 inches (100mm) for medium to large-sized pipes and equipment.

7. 6 inches (150mm) for larger industrial piping systems.

8. 8 inches (200mm) and larger for heavy-duty industrial applications with substantial pipe diameters.

It’s important to note that the availability of specific pressure ratings and sizes may vary depending on the manufacturing standards and the materials used for the flanges. When selecting forged flanges for a particular application, it is crucial to consider the pressure and size requirements and ensure that the flanges conform to the relevant industry standards and specifications. Proper selection and installation of flanges are essential to maintain the safety and integrity of the piping system.

Sino Special Metal is a trusted provider of high-quality forged flanges. With a strong reputation for excellence in the industry, Sino Special Metal has consistently delivered top-tier products that meet and exceed the stringent demands of various applications.

Our forged flanges are crafted with precision and expertise, ensuring exceptional strength and durability. Sino Special Metal offers a diverse range of flange types, materials, and sizes, making it easier to find the perfect solution for your specific requirements. Whether it’s for low-pressure systems or the most demanding high-pressure and high-temperature environments, our flanges are designed to perform with unwavering reliability.

Sino Special Metal adheres to strict quality control and industry standards, assuring customers of the highest levels of safety and performance. Our commitment to excellence extends to providing outstanding customer service and technical support, making the sourcing process efficient and hassle-free.

When you choose Sino Special Metal for your forged flange needs, you can trust that you’re investing in a product that exemplifies precision engineering, material integrity, and a dedication to delivering products that stand the test of time. Experience the difference with Sino Special Metal’s forged flanges, where quality meets reliability for your critical applications.

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