SA 516 Gr 70 Flange is a flange made from ASTM A516 Grade 70, a popular carbon steel grade widely used for pressure vessels and boilers. This grade offers high strength, excellent notch toughness, and resistance to corrosion, making it ideal for use in moderate to low-temperature applications. The SA 516 Gr 70 material is primarily used in industries such as oil and gas, chemical processing, and power generation, where pressure containment and durability are critical.

Key Features of SA 516 Gr 70 Flange:

1. High Tensile Strength: SA 516 Gr 70 steel offers a minimum tensile strength of 485 MPa (70,000 Psi), providing excellent durability and resistance to stress under pressure.

2. Notch Toughness: The material has excellent notch toughness, which ensures that the flange can withstand impacts and avoid brittle fractures, even at lower temperatures.

3. Corrosion Resistance: Although not as resistant to corrosion as stainless steel, SA 516 Gr 70 flanges perform well in environments where moisture, chemicals, or mild corrosive substances are present.

4. Weldability: SA 516 Gr 70 material is highly weldable, allowing for easy fabrication and the creation of complex piping systems without the risk of cracks or defects in the welds.

5. Pressure and Temperature Resistance: These flanges can handle moderate to high-pressure systems and are suitable for lower-temperature applications, making them ideal for pressure vessels and industrial boilers.

Common Types of SA 516 Gr 70 Flanges:

• Weld Neck Flange: Designed for high-pressure and high-temperature applications, these flanges are welded directly to the pipe, offering a smooth transition for stress distribution.
• Slip-On Flange: This type of flange is slipped onto the pipe and then welded, offering easy installation for systems operating at lower pressures.
• Blind Flange: Used to seal off a pipeline or vessel opening, providing flexibility for future expansion or maintenance.
• Socket Weld Flange: This flange type is used in high-pressure systems, especially for small-diameter pipes, to ensure a strong and leak-proof connection.
• Threaded Flange: Ideal for low-pressure systems, this flange is screwed onto the pipe without the need for welding.
• Lap Joint Flange: Used with a stub end, this flange allows easy assembly and alignment, especially in systems that require frequent disassembly.

Applications:

• Pressure Vessels and Boilers: SA 516 Gr 70 flanges are commonly used in the manufacturing of pressure vessels, steam boilers, and other equipment that handles high pressures.
• Oil and Gas Industry: These flanges are suitable for pipelines and other pressure-containing applications in oil refineries, gas processing plants, and offshore rigs.
• Chemical and Petrochemical Plants: SA 516 Gr 70 flanges are used in chemical processing where resistance to chemical corrosion and strength at moderate temperatures are required.
• Power Generation: They are used in power plants, including steam systems and heat exchangers, where they need to withstand high pressures and lower operating temperatures.
• Storage Tanks: Flanges made from SA 516 Gr 70 material are used in constructing storage tanks that store liquids and gases under pressure.

Mechanical Properties:

• Tensile Strength: 485 MPa (70,000 Psi) minimum
• Yield Strength: 260 MPa (38,000 Psi) minimum
• Elongation: 17%-21% in 200 mm, depending on thickness
• Impact Toughness: Excellent impact resistance, making it suitable for pressure and low-temperature environments.

Advantages:

• Strength and Durability: SA 516 Gr 70 flanges offer high tensile and yield strength, making them capable of withstanding high internal pressures and mechanical stress.
• Temperature Resistance: The material is designed to perform well in lower temperature environments, resisting brittle fracture and providing long-lasting service in moderate temperatures.
• Cost-Effective: SA 516 Gr 70 offers a good balance of strength, toughness, and affordability, making it a cost-effective choice for pressure vessel and industrial piping applications.
• Customizable: Available in a wide range of sizes and configurations, SA 516 Gr 70 flanges can be customized to fit specific project requirements.

Standards and Specifications:

• ASTM A516: This is the standard specification that governs the production of pressure vessel plates made from carbon steel.
• ASME Section II: The material complies with ASME standards for pressure vessels and boilers.
• ANSI/ASME B16.5: For the dimensions and pressure ratings of SA 516 Gr 70 flanges, ensuring compatibility with various piping systems.

Surface Treatment:

SA 516 Gr 70 flanges can be treated with additional surface coatings to enhance their corrosion resistance. Some common treatments include:

• Galvanization: Applying a layer of zinc for corrosion protection.
• Black Oxide: Offering a protective finish and improving wear resistance.
• Painting or Coating: Using specialized coatings for added protection in corrosive environments or high-temperature systems.

Thickness and Sizes:

SA 516 Gr 70 flanges are available in a wide range of sizes, from ½ inch to 60 inches or more, depending on the specific application. They are commonly manufactured in pressure ratings from 150# to 2500# (ANSI), with custom thicknesses available to suit various pressure vessel and piping system designs.

Maintenance:

• Regular Inspection: Despite their strength, it’s recommended to inspect these flanges periodically for signs of wear, corrosion, or fatigue in high-pressure systems.
• Surface Treatment Upkeep: Coatings and galvanization may need reapplication over time, depending on environmental conditions and exposure.

SA 516 Gr 70 Flanges are a versatile, reliable choice for a wide range of industrial applications that require high strength, good toughness, and resistance to moderate corrosion, making them ideal for use in pressure vessels, boilers, and high-pressure piping systems.