Principle and characteristics of flat welding flange

The issue of flat welding flanges has always been a topic of concern to people. It is related to the production costs or economic benefits of companies and enterprises. Therefore, the sealing principle of flat welding flanges has been continuously improved and improved.

However, the main design disadvantage of a flat welded flange is that it does not guarantee no leakage. This is the shortcoming of its design: the connection is dynamic, and such as thermal expansion and undulating cyclic loading will cause movement between the flange faces, affect the function of the flange, and thus damage the integrity of the flange, eventually leading to leakage. No product can be free of defects, but it is necessary to control the shortage of the product to the minimum, so the company will try its best to improve the performance of the product in the production of flat welding flanges, so that it can play the greatest role.

The characteristics of flat welded flange: Flat welded flange not only saves space and weight, it is more important to ensure that joints will not leak and has good sealing performance. The reduced size of the compact flange is due to the reduced diameter of the seal, which will reduce the cross-section of the sealing surface. Second, the flange gasket has been replaced by a sealing ring to ensure that the seal faces the sealing surface. In this way, only a small amount of pressure is required to compact the cover. As the required pressure is reduced, the size and number of bolts can be reduced accordingly, so a new design with a small size and light weight (70% to 80% lighter than traditional flanges) is designed. product. Therefore, the flat welding flange type is a relatively high-quality flange product, which reduces the quality and space and plays an important role in industrial applications.

Sealing principle of flat welding flange: The two sealing surfaces of the bolt squeeze the flange gasket against each other and form a seal, but this also causes the seal to be damaged. In order to maintain the seal, a large bolt force must be maintained, and for this reason, the bolt must be made larger. Larger bolts need to match larger nuts, which means that larger diameter bolts are needed to create conditions for tightening the nut. However, the larger the diameter of the bolt, the more suitable the flange becomes. The only way is to increase the wall thickness of the flange. The entire device will require significant size and weight, which becomes a particular problem in offshore environments, where weight is always the main concern that people must pay attention to. And, fundamentally, the flat welding flange is an ineffective seal, which requires 50% of the bolt load to be used to squeeze the gasket, and only 50% of the load to maintain pressure is left.