Flat welding flanges are mainly used for gas valves and natural gas pipelines. Because a short neck can improve the stiffness and load-bearing capacity of the flange. Flat welding flanges are used for general media. Flat welding flanges with necks are suitable for flammable, explosive, corrosive, and toxic environments. The sealing surface of flat welding flanges can be convex, concave convex, and mortise and tenon surfaces. They are different in structure, sealing effect, and strength.
Flat welding flanges are generally referred to as flat plates, also known as lap welding flanges. The connection between flat welding flange and pipeline is to insert the pipeline into the flange hole to the appropriate position before lap welding. The characteristics of flat welding flanges: Flat welding flanges not only save space and reduce weight, but also ensure no leakage at the joint and good sealing performance. The reason for the reduction in the size of compact flanges is the decrease in the diameter of the seal, which will reduce the cross-section of the sealing surface. The advantages of flat welding flanges are as follows:
1. To compact the sealing surface of the flat welding flange, only a small amount of pressure is required. As the required pressure decreases, the size and quantity of bolts also decrease accordingly.
2. The production of flat welding flanges can save data and reduce costs. When the raw materials of pipelines are special and the price is high, the welding cost of flanges made of the same raw materials will be very high. Using this type of flange can effectively save material costs. This type of flat welding flange is very suitable for construction, as it is inconvenient to align the flange bolt holes during connection or to avoid replacing the equipment flange bolt holes.
3. Flat welding flanges can save space and reduce weight during application. It is important to ensure that the head does not leak air. It has excellent sealing function. The reason for the reduction in the size of compact flanges is due to the decrease in the diameter of the seal, which reduces the cross-section of the sealing surface. In addition, flange gaskets have now been replaced by sealing rings to ensure excellent matching of flat welded flange seals facing the sealing surface.
But it also has some drawbacks, the drawbacks of flat welding flanges:
The main disadvantage of flat welding flanges is that they cannot guarantee no leakage. This is the lack of planning: the connection is dynamic, and cyclic loads such as thermal expansion and fluctuations can cause movement between flange faces, thereby affecting the function of the flange, damaging its integrity, and leading to leakage.
