Research on the metal sealing performance of plug valves based on the pressure penetration simulation method

ZHANG Shulin; PANG Hao

doi:10.16579/j.issn.1001.9669.2026.08.015

Abstract：[Objective]The reliability problem of metal-to-metal sealing for plug valves under high-temperature and high-pressure conditions in deep oil and gas extraction remains to be solved.The influence laws of key geometric dimensions of arc segments and plugs on sealing performance were investigated,so as to provide reference for high-reliability design of plug valves.[Methods]Firstly,a finite element simulation method based on pressure penetration mechanism was adopted,a pressure criterion related to surface roughness was established,and the penetration process of medium along the contact interface was dynamically simulated to realize analysis of sealing behavior under multi-factor coupling.Secondly,five sets of assembly models with different outer arc diameters were constructed,and contact characteristic calculations under multiple pressure levels were performed to clarify the influence of outer arc dimension on sealing band formation and contact pressure distribution.Then,with the optimal outer arc dimension fixed,five sets of models with different inner arc diameters were established,and the influence mechanism of inner arc dimension and assembly clearance on sealing performance was analyzed.Finally,multiple sets of dimension samples were fabricated and high-pressure sealing tests were conducted to verify the reliability of simulation conclusions.[Results]The results show that when the outer arc diameter is 145.35 mm,a continuous and effective sealing band can be formed in the plug valve over the full pressure range of 5 000 psi-15 000 psi,with optimal comprehensive sealing performance and a distinct optimal size range.The inner arc diameter exhibits an approximately linear negative correlation with sealing performance.When the inner arc diameter is 126.01 mm,the assembly clearance reaches the minimum,the contact pressure distribution is more uniform,the sealing band width increases significantly,and the sealing reliability is effectively improved.