Abstract: To make the pressure balanced plug valve meet the required strength and also the necessary RT(Radiographic Test) specified by customers, different structural types of valves are analyzed. Based on the valve design standards such as API 6D, API 599 and ASME B16.34, three-dimensional models of plug valves in different structural types are established. FEA(Finite Element Analysis) is performed on different models under the same boundary conditions and constraint conditions, in order to find the qualified valve structure. The analysis result shows that the plug valve with spherical structure can fulfill the requirements of strength, without the disadvantages of plug valve with stiffened structure such as unavailable RT operation and inaccurate result of RT. This kind of valve has significant advantages on internal quality control of structure components.