Weld neck flanges are a type of flange used in piping systems to connect pipes, valves, and other equipment. They feature a long neck that gradually tapers to the pipe, providing a strong and stable connection. This design helps to reduce stress at the joint, making them suitable for high-pressure applications. These flanges are typically made from materials like carbon steel, stainless steel, or alloy steel, and are available in various sizes and pressure ratings. They are commonly used in industries such as oil and gas, chemical processing, and water treatment due to their durability and reliability.