1. Full Face (FF):
The flange has a smooth surface, simple structure, and convenient processing. It can be used in situations where the pressure is not high or the temperature is not high. However, the contact area between the sealing surface and the gasket is large, requiring a large compression force. During installation, the gasket should not be placed, and after pre tightening, the gasket is easy to extend or move to both sides. When using lined flanges or non-metallic flanges, the FF surface flange ensures that the sealing surface does not break during tightening, especially the FF surface.
2 Raised Face (RF):
It has a simple structure and convenient processing, and can be used in situations where the pressure is not too high or the temperature is not too high. However, some people believe that using gaskets under high pressure is possible.
Due to its convenient installation, this flange is a widely used sealing surface form below PN 150.
3. Male and Female Face (MFM):
Consisting of concave and convex surfaces, the gasket is placed on the concave surface. Compared to flat flanges, concave convex flange gaskets are less prone to compression, easier to assemble, and have a larger working pressure range than flat flanges, making them suitable for strict sealing requirements. However, for equipment with high operating temperatures and large sealing diameters, some people believe that the gasket may still be squeezed out when using this sealing surface.
4. Tongue face flange (TG)
The method of mortise groove flange consists of groove surface and groove surface, and the gasket is placed in the groove. Like concave and convex flanges, tenon and groove flanges do not compress in grooves, so their compression area is small and the gasket is evenly stressed. Due to the fact that there is no direct contact between the gasket and the medium, the medium has little impact on the corrosion and pressure of the flange sealing surface. Therefore, it is often used in occasions with strict sealing requirements for high pressure, flammable, explosive, toxic media, etc. This sealing surface gasket is relatively simple and advantageous during installation, but its processing and replacement will become more difficult.
5. Ring Joint Face (RJ)
The flange sealing surface gasket is placed in the annular groove. Place the gasket in the ring groove so that it does not compress into the groove, with a small compression area and uniform force on the gasket. Due to the fact that there is no direct contact between the gasket and the medium, the medium has little impact on the corrosion and pressure of the flange sealing surface. Therefore, it is often used in occasions with strict sealing requirements for high pressure, flammable, explosive, toxic media, etc.
In summary, the sealing surface forms of flanges are different, and their characteristics and application ranges are also different. So, when choosing a flange, we must pay attention to its usage and performance requirements. For example, when the work is not harsh, choose an RF sealing surface, and when the working conditions are harsh, choose an RJ sealing surface that fully meets the sealing requirements; It is better to use FF surface in non-metallic or lined flange low-pressure pipelines. The specific situation depends on the actual needs.
Post time: Apr-18-2023
