The role of O-rings

The sealing principle of the O-ring is to use the compressive stress of the O-ring to seal. The O-ring is inserted into the groove, and the corresponding stress occurs with the elastic recovery of the rubber, and a certain initial contact pressure Po is generated on the contact surface. Even if there is no medium pressure or the pressure is very small, the O-ring seal can be sealed by its own elastic force; when the chamber is filled with a pressurized medium, under the action of the medium pressure, the O-ring seal is displaced , moves to the low pressure side, and at the same time its elastic deformation further increases, filling and closing the gap δ.