1) The relationship between compression rate and tensile amount and permanent deformation
2) Relationship between temperature and O-ring tensioning process
3) Medium working pressure and permanent deformation The compression permanent deformation rate of O-ring material is related to temperature. When the deformation rate is 40% or greater, there will be leakage, so the heat resistance of several kinds of glue is: nitrile rubber 70 ℃, EPDM 100 ℃, fluorine rubber 140 ℃. Therefore, the permanent deformation of O-ring is stipulated in various countries. The size changes of O-rings of Chinese standard rubber materials at different temperatures are shown in the table. The O-Ring of the same material has a low permanent deformation rate of O-ring compression with a large section diameter at the same temperature. The situation in the oil is different. Since the O-ring does not come into contact with oxygen at this time, it occurs in the dynamic seal state. O-Ring If the assembly is properly assembled and the conditions of use are appropriate, it is generally not easy to produce rolling or twisting in a reciprocating state, because the contact area between the O-ring and the groove is greater than the friction contact area on the sliding surface, and the resistance of the O-ring itself can prevent distortion. The distribution of friction also tends to keep the O-ring stationary in its groove, because the static friction is greater than sliding friction, and the roughness of the groove surface is generally inferior to the roughness of the sliding surface.
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