Flanges are parts that connect shafts to shafts and are used for connecting pipe ends. Flange connection or flange joint refers to a detachable connection made of flange, gasket and bolt which are connected to each other as a group of assembled sealing structures. Pipeline flanges refer to the flanges for piping in pipeline devices and the import and export flanges of equipment when used in equipment. There are holes in the flange and bolts hold the two flanges together. Gasket seals between flanges.

Flanges are used in pairs, with gaskets placed between the two flanges and bolted. Flanges at different pressures have different thicknesses, and they use different bolts. Pumps and valves, when connected to pipes, are also made into the corresponding flange shape, also known as flange connection.

Gasket is a mechanical seal between two objects, usually used to prevent pressure, corrosion, and natural thermal expansion and contraction leakage of the pipeline between two objects. Since machined surfaces cannot be perfect, irregularities can be filled with gaskets. Gaskets are usually made of sheet materials such as pad paper, rubber, silicone rubber, metal, cork, felt, neoprene, NBR, fiberglass or plastic polymers (such as PTFE). Gaskets for specific applications may contain asbestos.

Bolt is a mechanical part with a cylindrical threaded fastener fitted with a nut. A type of fastener consisting of a head and a screw (a cylinder with external threads) that is fitted with a nut for fastening two parts with through-holes. This type of connection is called bolt connection. If the nut is unscrewed from the bolt, the two parts can be separated, so the bolt connection is a detachable connection.