Detailed Explanation of Three Types of Flange Gaskets And Their Usage Characteristics
The selection of flange gaskets, as key sealing components in pipeline flange connections, is directly affected by the medium, pressure, and temperature. In the process of flange connection, gaskets play a crucial role in significantly improving the sealing performance of the connection and ensuring the stable operation of the system.
Usually, there are various types of gaskets, including graphite gaskets, metal gaskets, asbestos rubber gaskets, etc. These different types of gaskets have different usage characteristics. Next, we will delve into three common stainless steel flange gaskets and their respective characteristics. ​First, let's focus on the metal gasket.
The tooth-shaped metal gasket is carefully machined with tapered grooves on its sealing surface, which is particularly suitable for concave convex flange sealing surfaces. In addition, octagonal and elliptical gaskets are suitable for trapezoidal groove flange sealing surfaces, while lens gaskets are specifically designed for lens flange sealing surfaces. These metal gaskets can be made of various materials such as pure iron, ultra soft steel, stainless steel, or aluminum, ensuring the diversity of their sealing performance.
In the manufacturing process, the machining accuracy and surface roughness of the sealing surface need to meet strict standards. At the same time, the bolt clamping force is also quite large, which enables the metal gasket to maintain stable sealing performance in high temperature and high pressure environments. It is worth mentioning that the metal coated graphite gasket commonly used in high-temperature and high-pressure valves is refined from thin metal coated annular asbestos gaskets, which are particularly suitable for concave convex flange sealing surfaces and can maintain excellent sealing effects at high temperatures and pressures.
Asbestos rubber gasket is a sealing material suitable for high temperature and medium pressure valves, which is for smooth, concave convex, and mortise and tenon flange sealing surfaces. Its advantages lie in good corrosion resistance and thermal stability, as well as high plasticity, which can achieve sealing with less compression force. However, its disadvantage is that its strength is relatively low and it is easy to adhere to the flange sealing surface. There are various types of asbestos rubber gaskets, including universal asbestos board, corrosion-resistant asbestos board, and asbestos board made according to specific purposes such as acid resistance, oil resistance, or metal wire clamping.
Graphite gaskets, one flat gasket made of soft graphite, are particularly suitable for high temperature and highly corrosive media. It is mainly used for mortise and tenon sealing surfaces and can be made of materials such as polytetrafluoroethylene or fiberglass polytetrafluoroethylene. It is fit for strong corrosive media under various pressures and can maintain stability at lower temperatures. In addition, the flange gasket plays a buffering role at the connection, effectively preventing direct contact between the steel plate and extending the service life of the flange.
