The 1 1/4″ Pipe Flange is a crucial component in piping systems, facilitating the connection of pipes and components. Its key features and benefits include:

socket weld flange

Key Features:

  • Wide Applicability: Designed for 1 1/4-inch diameter pipes, it is compatible with a variety of pipes and equipment, simplifying integration into piping networks.
  • Material Versatility: Available in different materials like stainless steel, carbon steel, and alloy steel, allowing customization for specific applications, such as corrosion resistance or durability.
  • Easy Installation: Simple installation ensures a secure, leak-free connection, reducing the risk of system failures.


  • Leak Prevention: The 1 1/4″ Pipe Flange forms a robust seal with gaskets and bolts, preventing fluid leaks, saving costs, and minimizing hazards.
  • Maintenance-Friendly: Its design allows for easy disassembly and reassembly, simplifying maintenance tasks and reducing downtime.
  • Versatility: With various flange types and material options, it suits applications in chemical processing, oil and gas, water treatment, and more.

In summary, the 1 1/4″ Pipe Flange is an essential component in piping systems, offering compatibility, leak prevention, ease of maintenance, and adaptability to diverse industrial applications.

Certainly, here are the detailed specifications for the 1 1/4″ Pipe Flange in English:

SpecificationDetailed Description
Size1 1/4 inches (Inches)
Pressure RatingANSI 150, ANSI 300, ANSI 600, ANSI 900, ANSI 1500, ANSI 2500
MaterialStainless Steel, Carbon Steel, Alloy Steel, or other specialized alloy materials (per customer requirements)
Flange TypeWeld Neck, Slip-On, Blind, Threaded, Forged, Lap Joint, Threaded Neck, Socket Weld, Flat Face, or other specialized types (per customer requirements)
Surface FinishSmooth, Raised Face, Concave Face, Oval, or other specialized surface finishes (per customer requirements)
Gasket CompatibilityDesigned for compatibility with various gasket materials, including rubber, metal, graphite, and others, to ensure effective sealing.

These specifications provide a comprehensive overview of the 1 1/4″ Pipe Flange, including its size, pressure rating, material, flange type, surface finish, and gasket compatibility. If you require more information or a quotation, please feel free to contact our team, and we will provide personalized assistance and support.


  • Size: The 1 1/4″ Pipe Flange is designed to accommodate pipes with a 1 1/4-inch diameter. This standardized size ensures compatibility with a wide range of piping systems.
  • Material Options: These flanges are available in various materials to suit different environmental and operational needs, including but not limited to:
  • Stainless Steel: Suitable for applications requiring corrosion resistance, commonly in the food industry or chemical processing.
  • Carbon Steel: Known for its strength and durability, often used in high-pressure applications.
  • Alloy Steel: Combining strength and resistance to high temperatures, ideal for demanding environments like oil and gas.
  • Pressure Rating: The 1 1/4″ Pipe Flange is engineered to withstand different pressure levels depending on the material and design. Typical pressure classes include:
  • Class 150: Suitable for low-pressure applications.
  • Class 300: Used in moderate-pressure environments.
  • Class 600: Designed for high-pressure systems.
  • Higher classes available for specialized needs.
  • Standard Compliance: These flanges are manufactured in accordance with industry standards to ensure quality and reliability. Common standards include:
  • ASME B16.5: The American Society of Mechanical Engineers standard for pipe flanges and flanged fittings.
  • ANSI: American National Standards Institute standards, often used in the United States.
  • DIN: German Industrial Standards, widely adopted in Europe.
  • JIS: Japanese Industrial Standards, prevalent in Japan and some Asian markets.

Customization Options:

  1. Gasket Material: Depending on the application’s requirements, you can choose from various gasket materials, such as rubber, silicone, or PTFE, to ensure an optimal seal.
  2. Flange Type: Select the appropriate flange type for your needs. Options include slip-on, weld neck, socket weld, threaded, and more, each catering to specific connection methods.
  3. Coating or Lining: To enhance corrosion resistance or prevent material contamination, you can opt for flanges with specialized coatings or linings, such as epoxy or PTFE.
  4. Bolt and Nut Material: Customizing the material of bolts and nuts can improve overall flange performance and durability.
  5. Special Dimensions: For unique applications, customized dimensions and designs are available to meet specific requirements.

In conclusion, the 1 1/4″ Pipe Flange offers a range of specifications and customization options, allowing it to be tailored to diverse industrial needs while adhering to relevant standards for quality and safety.


Let’s explore the wide range of applications where the 1 1/4″ Pipe Flange is utilized and how it enhances the performance of piping systems in various industries and sectors:

1. Chemical Processing:

Use Case: Chemical processing plants often deal with corrosive substances. The 1 1/4″ Pipe Flange, with its material customization options (e.g., stainless steel), helps prevent corrosion, ensuring the integrity of pipelines carrying chemicals.

2. Oil and Gas:

Use Case: In the oil and gas industry, where high-pressure environments are common, the 1 1/4″ Pipe Flange with higher pressure ratings (e.g., Class 600) is employed to connect pipelines, valves, and pumps, ensuring safety and reliability.

3. Water Treatment:

Use Case: Water treatment facilities rely on these flanges to connect pipes carrying treated water. The 1 1/4″ Pipe Flange’s leak prevention capabilities are crucial for maintaining water quality and reducing wastage.

4. Food and Beverage:

Use Case: In the food and beverage industry, hygiene is paramount. The 1 1/4″ Pipe Flange, often made of stainless steel, facilitates clean and sanitary connections, preventing contamination.

5. Pharmaceuticals:

Use Case: Pharmaceutical manufacturing requires precision and cleanliness. Customized 1 1/4″ Pipe Flanges with specialized coatings or linings help maintain sterile conditions in pipelines.

6. Power Generation:

Use Case: Power plants, including nuclear and thermal facilities, rely on these flanges to connect various pipelines carrying steam, water, or fuel. The flanges’ material options and pressure ratings ensure safety and reliability.

7. HVAC (Heating, Ventilation, and Air Conditioning):

Use Case: In HVAC systems, these flanges connect pipes that distribute heating or cooling, enhancing energy efficiency and maintaining indoor comfort.

8. Construction and Building Services:

Use Case: Flanges are used in plumbing and heating systems within buildings to ensure reliable connections and prevent water leakage.

9. Shipbuilding and Marine Industry:

Use Case: These flanges play a vital role in shipbuilding by connecting various pipelines, including those for water, fuel, and hydraulic systems, ensuring the vessel’s functionality.

10. Aerospace:

Use Case: In aircraft and aerospace applications, precision and reliability are crucial. Customized flanges with special materials and coatings help maintain the integrity of fluid systems.

In each of these industries and sectors, the 1 1/4″ Pipe Flange enhances the performance of piping systems by providing leak-tight connections, facilitating easy maintenance, and offering material customization to meet specific environmental and operational requirements. Its versatility and compatibility make it a fundamental component in ensuring the efficiency and safety of various industrial processes.

Design and Construction

  1. Flange Types: The 1 1/4″ Pipe Flange is available in various types, including slip-on, weld neck, socket weld, and threaded. Each type has a specific design to cater to different connection methods, ensuring versatility.
  2. Materials: These flanges are crafted from a range of materials, such as stainless steel, carbon steel, and alloy steel. The choice of material depends on factors like corrosion resistance, temperature tolerance, and strength requirements, making it adaptable to diverse applications.
  3. Pressure Ratings: The flanges are engineered to meet various pressure ratings, accommodating both low and high-pressure systems. This ensures that they can withstand the demands of different industrial environments.
  4. Structural Integrity: The 1 1/4″ Pipe Flange is meticulously designed to provide structural integrity. It consists of two main parts:
    • Flange Face: The flat surface where the sealing gasket sits, ensuring a secure and leak-free connection.
    • Flange Rim: The raised edge that strengthens the flange and provides stability when bolted to another flange or component.
  5. Bolt Holes: Precisely positioned bolt holes allow for secure attachment to other flanges or equipment. The number and size of these holes depend on the flange’s size and class.
  6. Gasket Seat: The flange’s design includes a gasket seat where the sealing gasket is placed. This ensures a tight seal when the flange is bolted to another flange or component.

Unique Characteristics and Innovations:

  1. Material Customization: One of the standout features of the 1 1/4″ Pipe Flange is its extensive material options. This flexibility allows for tailoring the flange to the specific needs of an application, whether it’s for extreme corrosion resistance or high-temperature environments.
  2. Coatings and Linings: Many manufacturers offer coatings and linings for these flanges, enhancing their resistance to corrosion and chemical reactions. These protective layers can significantly extend the flange’s lifespan.
  3. Precision Engineering: Competent manufacturers employ precision engineering techniques to ensure that each flange conforms to industry standards and specifications. This dedication to quality control ensures consistency and reliability.
  4. Innovative Sealing Solutions: Some flange designs incorporate innovative sealing solutions, such as self-energizing gaskets, which further improve leak prevention and durability.
  5. Customization Options: Manufacturers often provide customization options for bolt materials, dimensions, and additional features like flange facings, ensuring that the flanges meet the precise requirements of different industries and applications.

In summary, the 1 1/4″ Pipe Flange is designed and constructed with a focus on structural integrity, durability, and adaptability to various industries. Its extensive material options, precise engineering, and potential for customization set it apart from competitors, making it a reliable choice for a wide range of piping system needs.

Installation Guidelines

Installation Steps:

1. Gather Your Materials and Tools:

  • 1 1/4″ Pipe Flange
  • Gasket (appropriate for your application)
  • Bolts and Nuts (corrosion-resistant if needed)
  • Wrenches or Socket Set
  • Proper safety equipment

2. Prepare the Flanges:

  • Ensure that the flange faces are clean, free of debris, and flat.
  • Check the gasket for any defects or damage, and make sure it is the correct size and type for your application.

3. Position the Flanges:

  • Align the flanges with the pipe ends, ensuring that they are perfectly centered and parallel. Misalignment can lead to leaks.

4. Insert the Gasket:

  • Place the gasket carefully between the flange faces, making sure it sits evenly. Some gaskets may require a lubricant or sealant; follow the manufacturer’s recommendations.

5. Insert Bolts and Nuts:

  • Insert the bolts through the bolt holes in one of the flanges.
  • Hand-tighten the nuts onto the bolts, ensuring that they engage properly without cross-threading.

6. Tighten the Bolts:

  • Begin tightening the bolts in a star or crisscross pattern. This distributes pressure evenly and prevents warping or distortion of the flange.
  • Gradually increase the torque on each bolt until they are snug.

7. Torque to Specifications:

  • Use a torque wrench to apply the final torque to the bolts. Refer to the manufacturer’s specifications or industry standards for the recommended torque values based on the flange class and size.

8. Inspect the Connection:

  • Visually inspect the flange connection for any gaps or misalignment.
  • Ensure that the gasket is properly compressed but not over-tightened, as this can damage the gasket.

9. Conduct a Leak Test:

  • Perform a leak test, which may involve pressurizing the system with water or air to check for any leaks around the flange connection. Address any leaks immediately.
How to install pipe flanges?

Helpful Tips and Precautions:

  1. Cleanliness: Keep the flange faces and gasket clean and free from contaminants to ensure a proper seal.
  2. Proper Gasket Selection: Choose the right gasket material and type for your application, considering factors like temperature, pressure, and the fluid being conveyed.
  3. Even Bolt Torque: Apply even and gradual torque to the bolts to prevent uneven pressure on the gasket, which can lead to leaks.
  4. Flange Alignment: Ensure the flanges are perfectly aligned before tightening the bolts to avoid stress on the connection.
  5. Torque Specifications: Always follow the manufacturer’s torque specifications or industry standards to prevent over-tightening or under-tightening.
  6. Leak Testing: Perform a thorough leak test after installation to identify and rectify any issues before the system goes into operation.
  7. Safety: Use proper safety equipment, and follow safety guidelines when working with piping systems, especially in high-pressure applications.

By following these installation guidelines and taking necessary precautions, you can ensure a successful and reliable installation of the 1 1/4″ Pipe Flange, promoting the integrity and efficiency of your piping system.

Quality Assurance

Ensuring the quality of the 1 1/4″ Pipe Flange is paramount to its reliability and performance in various industrial applications. Manufacturers typically implement stringent quality control measures throughout the manufacturing process to meet industry standards and certifications. Here’s an overview of the quality assurance practices commonly employed:

1. Material Selection:

  • Manufacturers carefully select materials such as stainless steel, carbon steel, or alloy steel based on the intended application’s requirements for strength, corrosion resistance, and temperature tolerance.

2. Raw Material Inspection:

  • All incoming materials undergo rigorous inspections to verify their quality and compliance with industry standards.

3. Precision Machining:

  • Flanges are machined with precision to ensure accurate dimensions and a smooth surface finish, essential for a proper seal.

4. Quality Checks at Various Stages:

  • Quality control personnel conduct inspections and measurements at different stages of the manufacturing process to identify and rectify any defects.

5. Non-Destructive Testing (NDT):

  • NDT methods such as ultrasonic testing, radiographic testing, and dye penetrant testing are often employed to detect internal defects and ensure the integrity of the flange.

6. Compliance with Industry Standards:

  • Manufacturers adhere to established industry standards and specifications, such as ASME B16.5 (American Society of Mechanical Engineers) and ANSI (American National Standards Institute), which provide guidelines for flange design, materials, and quality.

7. Certification:

  • Many manufacturers seek certifications from reputable organizations to validate the quality of their products. Common certifications include ISO 9001 (Quality Management System) and ASME certifications for specific product categories.

8. Traceability:

  • Manufacturers maintain detailed records of materials, processes, and quality control procedures, ensuring full traceability of each flange’s production history.

9. Inspection Documentation:

  • Inspection reports, material certificates, and test records are often provided with each flange to demonstrate compliance with industry standards and customer requirements.

10. Continuous Improvement:

  • Manufacturers prioritize continuous improvement by analyzing any quality issues or customer feedback and making necessary adjustments to enhance product quality.

11. Customer Satisfaction:

  • Ensuring customer satisfaction is a primary goal. Manufacturers welcome feedback and are responsive to any concerns or issues related to product quality.

By adhering to these stringent quality control measures and industry standards, the 1 1/4″ Pipe Flange’s reliability and performance are upheld. Customers can have confidence in the product’s durability, safety, and ability to meet the demanding requirements of various industrial applications.

Lewis Liu

Hello, I am Lewis Liu, a professional sales engineer with over ten years of experience in the flange fittings industry. I am highly knowledgeable in flange selection, installation, and maintenance. I am passionate about providing customers with the best solutions to ensure their pipeline systems run smoothly, safely, and reliably.

If you have any questions or concerns regarding flange fittings for your pipelines, whether it’s about selection, material choice, specification requirements, or any other aspect, please feel free to contact me at any time. I am committed to offering professional advice and assistance to help you make informed decisions and meet your needs.

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