The basic contact faces of flanges are flat faces, raised faces, male faces, female faces, tongue faces, groove faces and RTJ faces. The selection of contact faces of flanges is different based on working conditions, media, pressure, specifications, temperatures and other conditions. Let's know more information about these contact faces.
The flat face is flat and is suitable for places where pressure is not high and the media is non-toxic.
The raised face type sealing surface is the most widely used among these types we mention above. The international standard and the European system and the domestic standard all have fixed heights.
Male and female faces are two kinds of sealing surfaces which are a match, and they must be used together. They are applied to high pressure conditions. All kinds of non-metallic flat gaskets, metal gaskets and basic type gaskets are suitable for male and female faces.
Tongue faces and groove faces are similar to male and female surfaces. They are also used in pairs. Their gasket are located in the annular groove, and they are limited by the metal walls on both sides in order to prevent gaskets being squeezed in the pipeline due to deformation. Since the gasket is not directly in contact with the fluid medium in the tube, it is hardly corroded by the medium of the fluid, which makes the gasket be used for high pressure, flammable, explosive and toxic media places that have strict sealing requirements. It is difficult to process this kind of sealing surface. When we replace the gasket, the sealing surface is easily damaged. In addition, the flange must be separated in the axial direction during installation and disassembly. Therefore, when we design the pipeline, we should consider the possibility of separating the flanges in the axial direction. Gaskets used for tongue faces and groove faces are all kinds of metal and non-metal flat gaskets, metal gaskets and basic wound gaskets.
RTJ faces also belong to the narrow face flange. When we design the pipeline, we should consider the possibility of separating the flanges in the axial direction just like tongue faces and groove faces.
This kind of sealing surface is specially processed into an octagonal or elliptical gasket with a metallic material so as to seal the flange. This type of seal surface has good sealing performance and its installation requirements are not strict, which is applied to high temperature and high pressure working conditions. Though, the sealing surface has higher processing accuracy.