Using BS4504 standard, there are plate flanges, weld neck flanges, slip on flanges, threaded flange and blind flange, etc. About these types of flanges, will introduce their specific size pressure and other details Plate Flanges（Code101）
Plate type flat welding flange (chemical standard HG20592, national standard GB/T9119, mechanical JB/T81): easy to obtain materials, easy to manufacture, low cost and wide use. However, its rigidity is very poor, so it cannot be used in supply and demand, flammable and explosive chemical process piping systems. These systems need explosion and higher vacuum, and are very dangerous. The type of sealing surface is flat and convex.
The threaded flange is a non-welded flange, which is connected to the threaded pipe by processing the inner hole of the flange into pipe thread. Compared with flat welding flange or butt welding flange, threaded flange has the characteristics of convenient installation and maintenance, and can be used for pipes that do not allow field welding. Alloy steel flange has sufficient strength, but it is not easy to weld, or the welding performance is not good, threaded flange can also be selected. However, when the pipe temperature changes rapidly or the temperature is higher than 260 ° C but lower than – 45 ° C, it is recommended not to use threaded flange to avoid leakage.
Flange cover is also called blind flange, blind plate. This is a flange without a hole in the middle, which is used to seal the pipe plug. This function is the same as that of welded joint and threaded pipe cap. The difference is that the blind flange and threaded pipe cap can be removed at any time, but the welding head cannot be removed. There are many types of sealing surfaces, including flat, convex, concave and convex, tenon and groove surfaces and annular connection surfaces.
American standard flanges are components that connect pipes to pipes and pipe ends. American standard butt-welded flanges are forged and cast in two ways. American standard butt welding flange can be divided into necked American standard butt welding flange and non-necked American standard butt welding flange according to its neck conditions. American standard butt welding flange consists of two flange plates and flange gaskets. Flange washers are bolted together to complete the connection. American standard flange has holes, and bolts connect the two flanges tightly. The flange is sealed with gasket.
Weld Neck Flanges(Code 111) 
Slip On Flanges(Code 112)
Threaded Flanges(Code 113)
Blank Flanges(Code 105)
Post time: Feb-21-2023
