This kind of metal ring gasket is made of metal material by forging, heat treatment and machining into a solid metal gasket with an elliptical cross-sectional shape. It has a radial self-sealing effect and is a standard R-type metal ring gasket. The principle of action is to rely on the contact between the gasket and the inner and outer surfaces (mainly the outer side) of the flange trapezoidal groove, and to form a sealing effect by pressing.
The oval metal ring gasket is installed in the trapezoidal ring groove on the flange surface. When the connecting bolt is tightened, it is axially tightened and tightened with the upper and lower trapezoidal grooves, resulting in plastic deformation, forming an annular sealing belt and establishing an initial seal. After boosting, under the action of medium pressure, the ring gasket is radially expanded.
The gasket and the inclined surface of the trapezoidal groove are more tightly attached, resulting in a self-tightening effect. However, the increase of the medium pressure will also deform the flange and the connecting bolt, forming a relative separation between the sealing surfaces, and the gasket sealing ratio is relatively reduced, so the ring gasket can be regarded as a semi-self-tight seal.
The oval-shaped ring gasket and the flange groove are in line contact, and the sealing performance is good, but the processing accuracy is high, so the manufacturing cost is high. At the same time, the hardness of the oval-shaped metal ring gasket should be 15~20HB lower than that of the flange surface, and it is recommended that Do not use repeatedly.