are usually applied to the connection among pipelines, facilities, valves and pipe fittings. The casting of flange was originally proposed by Erchardt in 1809. However, it wasn’t adopted until the early 20th century. After that, flanges were gradually produced and applied into various industries. China has concentrated on the application and casting of flange pipe since 1930s.
Moulded and solidificated in rotation state, flanges boast the following characteristics:
First, the liquid metal can be made into a hollow cylinder without mold core. This feature can greatly reduce the costs and increase the productivity due to the simplification of casting process.
Second, the power generated during rotation can upgrade the quality of mold filling. This technology can be used in other production such as the less liquid alloy and thin-wall casting.
Third, gas and non metallic impurity can be easily eliminated during the process. Therefore, the flange castings have little weak points and great mechanical property.
Fourth, this process leads to high usage of metal. In 2014 and even the following decades, the energy conservation will greatly benefit our society.
The sealing gasket used for flanges are chosed on base of the features of transported media, temperatures and pressures of working environment. The common gaskets are rubber gaskets, rubber asbestos gaskets, asbestos gaskets, metal gaskets, etc. In order to guarantee the sealing performance of gaskets, the both sides of gaskets should be painted with sealant to prevent media from sealing. By the way, the sealant should be unable to react with the media.
Different flanges are adopted according to the pressure and type of the media, as well as the materials of pipelines. The generally used flange types include slip on flanges
, welding neck flanges, lap joint flanges and so on.