Forged flanges are components used for connecting pipes together at the pipe ends. They have holes for bolts that securely fasten the two flanges. Sealing is achieved between the flanges with gaskets. Forged flanged pipe fittings refer to pipe fittings equipped with forged flanges (also known as collars or hubs). They can be cast (image temporarily unavailable), threaded, or welded. A flange joint consists of two flanges, a gasket, and several bolts and nuts. The gasket is placed between the sealing surfaces of the flanges, and when the nuts are tightened, the surface pressure on the gasket reaches a certain value, causing it to deform and fill in any irregularities on the sealing surface, ensuring a tight and leak-proof connection. Flange joints are a type of detachable connection. They can be categorized by the components they connect, such as vessel flanges and pipe flanges. Structurally, they are classified into integral flanges, slip-on flanges, and threaded flanges. Common integral flanges include flat welding flanges and socket welding flanges. Flat welding forged flanges have lower rigidity and are suitable for pressures p≤4MPa; socket welding flanges, also known as high-neck flanges, have higher rigidity and are used in high-pressure and high-temperature applications.