Material selection and whether the valve can work properly is of great significance. Compared with globe valve and gate valve, the structure of butterfly valve avoids deformation caused by irregular shape, uneven shell wall thickness, condensation and temperature difference at low temperature. And because the butterfly valve volume is small, the shape of the valve body is basically symmetrical, so the heat capacity is small.
In the operation of cryogenic valve, the rotating part of valve is not flexible. The main reasons are: the material selection is not reasonable, the machining accuracy is not high, the reserved clearance is small and so on. Metal sealed butterfly valve has the characteristics of some common valves do not have, such as small flow resistance, sealing reliable, open and close quickly, long service life and other advantages.