What are the performance characteristics and application scope of octagonal gasket? Octagonal gasket is a solid metal gasket with a cross-sectional shape of octagonal shape made of metal materials through forging, heat treatment, and mechanical processing. It has a radial self tightening sealing effect and is a type of standard R-type metal ring gasket. Its working principle is that the cushion gasket contacts the inner and outer surfaces (mainly the outer surface) of the flange ladder groove, and is compressed to form a sealing effect.
The octagonal gasket is installed in the ladder shaped groove on the flange surface. When the connecting bolt is tightened, it is compressed axially and pressed against the upper and lower ladder shaped grooves, causing plastic deformation and forming an annular sealing band, establishing the initial seal. After the pressure is increased, the ring gasket expands radially under the action of the medium pressure. The gasket is more tightly attached to the inclined surface of the trapezoidal groove, creating a self tightening effect. However, the increase in medium pressure can also cause deformation of the flange and connecting bolts, resulting in relative separation between the sealing surfaces and a relative decrease in the sealing ratio of the gasket. Therefore, the gasket can be considered a semi self tight seal.
The matching between octagonal gasket and flange groove is mainly surface contact. Although it is not easy to achieve a tight fit with the flange groove compared to elliptical gasket, it can be reused and is easy to process because the cross-section is composed of straight lines. At the same time, the hardness of the octagonal gasket material should be 15-20HB lower than that of the flange surface.
Octagonal gasket performance characteristics:
1. High temperature and high pressure resistance, suitable for high-pressure flanges;
2. Durable and reliable sealing;
3. Adapt to working conditions with fluctuating pressure and temperature;
Application scope of octagonal gasket: It is usually used for pipe flanges, tower tanks, pressure vessels, high-speed joint surfaces, high-temperature and high-pressure valves, and covers for high-temperature and high-pressure steam, gas, and solvents. Wellhead equipment and seals on Christmas trees in the petroleum and natural gas industry
Metal ring gaskets originated in the United States and were first used in the boiler industry in the 1920s. Later, they were used for sealing manhole covers and other windows of high-pressure reactors. They were particularly valued in petroleum production and refining industries. As the temperature and pressure of steam power plants increase, the use of metal gaskets becomes increasingly widespread.
We can provide over 30 types of materials, such as 321 SS, 347SS, 316SS, 304SS, Inconel 600,Inconel 625 ,Monel 400, Hastelloy C-276, lncoly825,Nickel 200,Duplex F44,Duplex F51,Duplex F53,Soft Iron,Low Carbon Steel,F5 wait; At the same time, it can produce gaskets with a maximum outer diameter of 2500mm.