Whether the silicone or rubber, software pectin products depends on extrusion deformation of the sealing effect, so when the pressure is greater than the pressure of seal medium sealing effect, less than when leakage occurs, the fundamental reason is due to the high pressure working environment of silicone rubber ring permanent deformation and piled into gap caused by the bite, so this is the core of the main factors, On the basis of this factor, there are several unavoidable factors.
First: working pressure leads to deformation and failure of silicone rubber ring; Pressure extrusion is silicone rubber ring permanent deformation of the culprit, the pressure of the medium for silicone rubber ring deformation is bigger, the influence of all industry one of the most common cause of silicone rubber ring deformation, with the development of modern hydraulic equipment, hydraulic medium pressure is more and more big, the silicone rubber circle for a long period of time in this kind of high-pressure work environment, can lead to permanent deformation, This deformation is irreversible, so different materials should be selected for different working pressures. Silicone or rubber materials with relative pressure resistance, wear resistance and temperature resistance should be selected. Accordingly, in order to cope with higher working pressure, the hardening degree of silicone rubber ring of pressure-resistant materials will also increase.
Second: failure caused by temperature; Temperature is very important for the relaxation of silicone rubber ring. No matter what kind of material, it will speed up its aging rate at high temperature. When the temperature in the environment is higher, the deformation of gas compression will be greater. When in installation of silicon rubber circle will be the initial stress, these will be asleep long relaxation of the silicone rubber ring and temperature gradually reduce and slowly disappear, in some cases could disappear as the temperature decreased sharply, even if the material is high and low temperature resistant silicone rubber products, when compared with 20 degrees of stress, is not greater than 25%, Therefore, the initial stress should be set when installing the silicone rubber ring, and the temperature in the working environment should be fully considered.
Third: compression and tensile factors; Because of the different kinds of rubber formula of silicone rubber ring, the compression amount and tensile strength of silicone rubber ring produced by different enterprises are different. Products under the conditions of long-term compression will produce compression stress relaxation phenomenon, this phenomenon will gradually expand over time, the longer the smaller amount of compression and tensile rate will, make its elasticity is insufficient cause leakage phenomenon, the most direct method of change is to increase the section size of products, but also leads to the increase of product on the structure.
Therefore, in the early use process, silicone rubber should be well selected. Its friction coefficient must be low, lubrication must be in place, and its contact surface must be smooth, not rough and stained. In the process of installation, it is necessary to ensure the coaxial installation, absolutely not too eccentric, but also to ensure the rationality of the sealing system, not too large size error phenomenon.