SA350 LF2 Long Welding Neck FLange For Cryogenic Piping and Equipment

Overview

The SA350 LF2 Long Welding Neck Flange is a type of flange that is commonly used in pressure vessel, piping, and industrial applications where strength, durability, and resistance to extreme conditions are required. The "SA350 LF2" refers to the material specification (ASTM A350, Grade LF2), and "long welding neck" refers to the specific design of the flange.

SA350 LF2 Long Welding Neck Flanges are widely used in industries where low-temperature toughness, strength, and the ability to withstand pressure are required. These flanges are particularly suited for applications in cryogenics, offshore oil and gas, chemical processing, and power generation systems. Their design, with the extended neck, ensures that they can provide a strong, secure, and durable connection in challenging and demanding environments.

Key Features of SA350 LF2 Long Welding Neck Flange:

1. Material (SA350 LF2):

• ASTM A350 LF2 is a low-alloy carbon steel that is designed for use in low-temperature environments. It is known for its excellent toughness at low temperatures and its ability to withstand moderate pressure.
• Chemical Composition: The material contains carbon, manganese, silicon, sulfur, and phosphorus with small amounts of other elements like chromium and molybdenum to enhance its strength and toughness at lower temperatures.
• Mechanical Properties: SA350 LF2 has good tensile and yield strength, along with high impact toughness at temperatures as low as -50°F (-45°C), making it suitable for low-temperature service.

​Long Welding Neck Design:

A long welding neck flange has a longer neck compared to a standard welding neck flange. This extended neck provides several advantages:

• Strength and Stability: The long neck enhances the strength of the flange, providing better alignment with the pipe and minimizing stresses in the welded connection.

• Ease of Welding: The long neck allows for easier and more secure welding, offering a larger area for the weld joint, which improves the integrity and reliability of the connection.

• Pressure Distribution: The long neck design helps distribute the stresses from internal pressure more evenly along the length of the flange, reducing the potential for failure.

Chemical Composition (%) of ASTM A350 LF2:

Mechanical Property Requirements of ASTM A350 LF2:

Applications of SA350 LF2 Long Welding Neck Flange:

Low-Temperature Service:

• Cryogenic Piping and Equipment
• Power Plants

Piping Systems in Harsh Environments:

• Oil and Gas Industry
• Chemical Processing

Pressure Vessel and Heat Exchanger Applications:

• Heat Exchangers
• Pressure Vessels

Pipeline Connections:

• In critical pipeline connections

Subsea and Offshore Applications

Cryogenic Storage and Transport:

• LNG storage tanks