National Standard Flange

Flange, also known as a flange disk or boss, is a component used for connecting shafts or for joining pipe ends; it is also used at equipment inlets and outlets, such as reducer flanges. A flange connection or flange joint refers to a removable joint that consists of a flange, a gasket, and bolts, forming a combined sealing structure. Pipe flanges are the flanges used for piping in pipeline installations; on equipment, they refer to the equipment's inlet and outlet flanges. Flanges have holes, and bolts secure them tightly together. They are sealed with a gasket. Flanges come in threaded (screwed) connections,焊接 (welded) flanges, and clamp flanges. Flanges are used in pairs; low-pressure pipelines can use threaded flanges, while those above four kilograms of pressure use焊接 flanges. Two flange disks are joined with a sealing pad and then fastened with bolts. Flanges of different pressures have different thicknesses and require different bolts. In the case of pumps and valves, when connected to pipelines, these equipment components are also shaped to match the flange, also known as flange connections. Any connection piece that uses bolts to connect two flat surfaces and is sealed is generally called a "flange," such as the connection of ventilation pipes, which can be referred to as "flange-type components." However, such connections are only a part of a device, like the connection between a flange and a pump, so it's not appropriate to call the pump a "flange-type component." Smaller components like valves can be called "flange-type components."