Research On Sealing Performance And Calculation Method Of Sealing Force Of Globe Valve With Soft Seal

Globe valve with soft seal is widely used in the chemical industry, aerospace, etc. Once its seal goes wrong, it will not only waste energy and raw material, but also affect the environment and even threat equipment normal operation. In the current study about sealing performance of globe valve with soft seal, the design of the sealing force still stay on the traditional empirical formula with a larger design margin. The traditional empirical formulas are not only unable to meet the continuous improvement of soft seal material, but also unable to show the influence of sealing force on the medium properties, even can not calculate the leakage rate quantitatively. So the traditional empirical formulas are not fit the lightweight and effective principle referred by aerospace. Aiming at calculation method of the sealing force of globe valve with soft seal in different leakage requirements, this paper references the tightness analysis method and raises a sealing force calculation method of the globe valve with soft seal based on leakage rate.The ABAQUS analysis software is used to establish the calculation model of sealing pair finite element of globe valve with soft seal and obtain the characteristic parameters of the disc gasket stress and deformation. Study on the influence of the medium pressure, the sealing force and the contact width to the characteristic parameters shows that the maximum stress and deformation of the disc gasket contact surface appears at the inside and outside edge of clack seat valve port contact area, and the contact stress of disc gasket at the inside valve port is larger than that at the outside valve port, as well as the contact stress and deformation of the gasket decreases with the increase of the contact width.The globe valve sealing test system is used to test the sealing performance of the FEP(F46) flat globe valve with soft seal. The sealing force of the globe valve with soft seal works in the case of 1.0～25.0MPa medium pressure and different leakage rate is measured. The law that the sealing pair effective contact width has an effect on sealing performance in the opening or closing process of globe valve with soft seal is studied. It shows that the sealing force is linearly related to the medium pressure in the case of globe valve with soft seal arriving setting leakage level. At the same sealing force, the leakage rate in the opening process is less than that in the closing process. The leakage rate of sealing pair decreases with the increase of the contact width.Aiming at the globe valve with soft seal disc gasket with synthetic resinous material, a sealing force calculation method of globe valve with soft seal is referenced based on the leakage rate calculation formula. Every coefficient of the formula is calculated by using the sealing performance test data of globe valve with soft seal and exponential curve model. The accuracy of the formula was verified by test, as well as the formula calculation numerical, the test numerical and the PVPC calculation numerical is compared with each other, which proves the accuracy of the calculation formula.Through the study on the sealing performance of globe valve with soft seal, the sealing force of globe valve with soft seal could be related with the leakage rate of the sealing pair, which offers a theoretical basis to design the sealing force drives of globe valve with soft seal.