Method for determining the sealing forces in a shut-off valve

Abstract

The developed method for determining the sealing forces in a shut-off valve takes into account the design features of its components and their elements, which affect the amount of sealing pressure. The components and assemblies of the shut-off valve that provide the creation of sealing pressure are referred to the fastening system or the sealing system. Dependences for determining the forces acting in these systems are analytically revealed. The values of forces are determined when tightening fasteners, when increasing and releasing pressure, as well as when they are exposed to temperatures. The calculation of the specific structure of the shut-off valve shutdown showed that the forces in the sealing system of the check valve prototype are 1.4 times higher than the values obtained using known calculation methods, and the forces in the mounting system of this check valve are 1.2 times higher than the calculated values. The magnitude of the discrepancy between the calculated and actual values of the forces for different designs of shut-off valves may differ and depends on the number of components included in the station shut-off valve. The proposed method for determining the sealing forces in the shut-off valve makes it possible to determine not only the forces in the shut-off valve, but also the optimal number of components and connections that will ensure safe operating conditions. It is shown that the method of calculating the forces in the station shut-off valve, used in practice, is a special case in which the stiffness coefficient of the station shut-off valve is equal to unity. The proposed method for determining the sealing forces in the shut-off valve makes it possible to more accurately determine the forces acting on the shut-off valve, the sealing conditions and the stress-strain state of the components. To implement the developed methodology for determining the sealing forces in the shut-off valve of the stop station in the shut-off valves, it is necessary to develop regulatory documents formalizing the application of this method.