A Socket Weld Flange (SW Flange) is a type of pipe flange specifically designed for small-diameter, high-pressure piping systems. It features a recessed socket (counterbore) into which the pipe is inserted before being secured with a fillet weld around the flange hub. This design provides a smooth bore, excellent flow characteristics, and a strong, leak-resistant joint, making it ideal for applications involving high pressure, high temperature, and critical process services.

Socket Weld Flanges are commonly used for pipe sizes up to NPS 2 (DN 50), where reliable performance and ease of installation are essential. Unlike threaded flanges, socket weld flanges eliminate the need for threading, reducing the risk of leakage while offering greater mechanical strength. The pipe is inserted into the socket with a small expansion gap (typically 1.6 mm or 1/16 inch) to accommodate thermal expansion during welding.

These flanges are manufactured in accordance with international standards such as ASME B16.5, ASME B16.47, EN 1092-1, DIN, JIS, and BS, ensuring compatibility with a wide range of industrial piping systems