The use of axial stops and polymer dynamic load absorbers in gates with thin-walled seals

Abstract

In sealing technology, there are valve joint designs, where various axial stops and polymer load absorbers are used to reduce radial deformations of the thin-walled seal in the gate. The use of polymer materials as axial limiters compensates for shock loads in the sealing joint and provides additional tightness (secondary sealing) of the joint with relatively little effort on the part of the drive. However, the use of polymer materials is limited by the operating conditions (chemical composition of the working medium, pressure of the working medium and other conditions). Polymer seals are squeezed out and destroyed at high pressures of the sealed medium. The change should also be noted in the physical and mechanical characteristics of polymers over time, under temperature, radiation, and other influences. The exclusive use of metal stops makes it possible to limit the impact of shock loads on a thin-walled seal, however, such design solutions lead to a decrease in the life of the sealing joint and limits the scope of application. Thus, the use of axial stops as deformation limiters can be provided in the design of the sealing joint in case of a significant excess of the pressure of the sealed medium over the calculated one reducing damage to the valve gate. To weaken the shock loads in the sealing joint, the gate can be «unloaded». The scientific article presents an overview and analysis of sealing joints in which the reduction of dynamic loads in the valve gate is compensated by axial stops and polymer load absorbers. The comparison of this method with one of the promising areas of improvement of valve connections – «unloading» is carried out. The actual designs of unloaded gates developed by the author are presented, which allow creating a thin-walled shell element of reasonable geometric dimensions, which, in turn, leads to a decrease in the hermetic effort and energy intensity of the drive. The conducted review and analysis showed that the presence of stops is necessary under conditions of unsteadiness of the sealed medium pressure, leading to significant changes in the component of the sealing force.