Contact Mechanical Performance and Fatigue Life of Sealing Surface of Plug Sampling Valve

The contact mechanical properties and fatigue life of plug sampling valve were studied in this paper. The mechanical analysis of the installation and sampling process of the plug sampling valve was carried out by applying the relevant mechanical theories. A theoretical model was established for the contact stress calculation of the contact surface in the installation process. A calculation model was established for the radial contact stress of the plug in the working process of the plug sampling valve. A calculation model was established for calculating the contact stress distribution of three typical cross sections of the plug surface. The contact stress distribution of the plug during sampling was verified by finite element method. Moreover, with a specific example, the variation and distribution of contact stress at each point on the plug surface during the sampling process were numerically calculated and studied. Based on the basic theory of fatigue life, the influences of pipeline working pressure and the amount of pressing in the process of plug installation on the fatigue life of plug were studied.