octagonal ring gasket

Octagonal gasket is a kind of Ring joint gasket with octagonal cross-section shape made of metal materials by forging, heat treatment and machining .It has the function of radial self-tightening seal. It is a kind of standard R-type Ring joint gasket. Its working principle is the contact between the backing sheet and the inside and outside (mainly the outside side) of the flange ladder groove, and the sealing effect is formed by pressing.

The octagonal Ring joint gasket is installed in the ladder ring groove on the flange surface. When the connecting bolts are tightened, they are tightly attached to the upper and lower ladder groove under axial compression, resulting in plastic deformation, forming an annular sealing belt, and establishing the initial seal.

After boosting, the Ring joint gasket expands radially under the action of medium pressure. The gasket is more closely attached to the inclined plane of the trapezoidal groove, resulting in self-tightening effect. However, the increase of medium pressure will also deform the flange and connecting bolt, resulting in the relative separation between the sealing surfaces and the relative decrease of gasket sealing ratio. Therefore, the ring gasket can be considered as a semi self-tightening seal.

Octagonal Ring joint gasket and flange groove match is mainly face contact, compared with oval ring gasket, although it is not easy to close with flange groove, but it can be used again, and because the section is composed of straight lines, it is easy to process. At the same time, octagonal metal ring gasket material should be selected, and its hardness should be lower than 15 ~ 20hb of flange face.