Flange is also called as flange plate, which is normally used for connecting two pipes together through the bolts or the welding method.
The flanges are available in various shapes and the most common ones include rectangular, oval and round. The type of flanges includes welding neck flange, slip on flange, socket weld flange, lap joint flange, threaded flange and blind flange
The materials of flanges
The most of flanges are usually made by grey iron. They have good corrosion resistance, wearing resistance, and it is very strong, non-deformation. Moreover, the cost of grey cast iron is cheap.The ductile iron flange is more expensive than grey iron, but it has better strength and elongation.
The application of flangesFlanges are commonly used in plumbing systems, water systems, electrical factory, pipe connection and building construction etc. It is convenient for maintenance and its life time is long. Flanges help to keep the pipes stay strong without the risks of leakage. In high pressure zones, welded flanges can prevent the pipes from corrosion, but they will reduce flow rate. In low pressure areas, it is recommended to use flanges with bolts as it facilitates smooth flow.
The surface treatment of flangesThe surface of flange should be used rust resistant coating, such as electro galvanizing, bituminous paint, powder coating and so on. All these coatings could prevent rust effectively. In general, sand casting process is fitted for the manufacture of flange. The necessary machining will be needed to meet the requirement of flatness. In China, most of iron foundries could produce flange castings.