Flange, also known as a flange dish or raised rim. A flange is a component used to connect shafts together or to join pipe ends; it's also used at equipment inlets and outlets for connecting two devices, such as a reducer flange. Flange connection or flange joint refers to a removable connection made up of the flange, gasket, and bolts working together as a sealed assembly. Pipe flanges are the flanges used in piping installations; on equipment, they refer to the equipment's inlet and outlet flanges. Flanges have holes, and bolts secure them tightly. They are sealed with a gasket. Flanges are available 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 varying thicknesses and require different bolts. In the case of pumps and valves, the parts that connect to pipes are also made in the shape of corresponding flanges and are referred to as flange connections. Any connection piece that uses bolts to join two flat surfaces and is sealed is generally called a "flange," such as the connection of ventilation pipes, which can be termed "flange-like parts." However, such a connection is 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-like part." Smaller components like valves can be referred to as "flange-like parts."