Due to the increasing number of product brands of sealants, the selection should be made according to the use conditions of the sealing part, the material of the sealing pair, the state of the joint surface of the sealing pair, the type and performance of the sealed medium and the curing conditions before use. . Regarding the conditions of use: including the stress state, working temperature, environment, and whether the sealing pair needs to be detachable, etc. Regarding the material of the sealing pair: generally, low-strength sealants can be used for non-metallic parts. For metal parts, high-strength sealants should be used. Regarding the state of the sealing pair: it includes the size and shape of the gap, surface roughness, and whether there is an oxide scale of the sealing pair in the assembled state. Generally, when the gap is large, or the surface is rough, the sealant with high viscosity should be used. When the sealing area is large or the sealing surface is smooth, the sealant with low viscosity should be used. Regarding the type of the sealed medium: the compatibility between the sealed medium and the selected sealant should be fully paid attention to, that is, to ensure the stability of the chemical and physical properties of the sealant itself under working conditions, so that it can be liquids are compatible with each other. Regarding curing conditions: If you choose anaerobic adhesive, you should pay attention to whether there are conditions to isolate it from the air. If the heating and complex process conditions that promote the curing of the glue cannot be achieved at the work site, other types of sealants that can be used at room temperature and do not need to be isolated from air should be selected. Alternatively, control and reduce the sealing clearance of the mating surfaces. At the same time, the catalyst component to shorten the curing time is increased in the glue solution of the anaerobic glue.