Flange in the mechanical design of what the role of general?

A discoid flange parts, most commonly in the pipeline, flange pairs are used. In the pipeline, the flange is mainly used for pipe connections. In the need to connect the pipe, flange mounted with a low pressure pipeline can use the wire connected flange, 4 kg more than the use of pressure welding flange. Between the two flange with seal point, and then tighten the bolts. Different pressures have different thickness of the flange and the use of different bolts. Pumps and valves, and pipe connections at the equipment the equipment locally, but also made the corresponding flange shape, also known as the flange connection. Any use of the two plane bolted around the same time in close connection parts, generally referred to as "flanges", such as ventilation pipe connections, the parts can be called "flange parts." But this is only a device to connect the local, such as flanges and pumps connected to water pump on the well known "flange parts." Such as valves and other relatively small, you can call "flange parts."