Chemical pump is the forever pursuit of chemical equipment without leakage, it is the request to the application of the shielding pump magnetic pump and expanding. But really no leakage is still a long way to go, such as magnetic pump isolation set of shielding and shielding pump sets of life problem, the material of pitting corrosion problem, the reliability of static sealing and so on. Now on the sealing some basic situation introduction is as follows: 1. For static seal, seal form usually only seal and seal two forms, and sealing ring with o-rings used most widely; Medium viscosity affect the performance of the pump is great, when the viscosity increases, the pump head curve dropped, the best working condition of the head and flow rate were decreased, while the power, and low efficiency. Generally the parameters for conveying water on the sample performance, should be reduced when the viscous medium. For high viscosity pulp, cream and viscous fluid conveying, screw pump is a suggested alternative. 2. Chemical pump seal material static sealing materials generally adopts the fluorine rubber, special situation to adopt ptfe material; Mechanical seal ring materials configuration is the key activity, not carbide carbide is best, the price is high on the one hand, both no hardness difference is not reasonable, so it's best to discriminate based on the medium. For dynamic seal, chemical pump packing seal, is scarcely used to is given priority to with mechanical seal, mechanical seal and single face and double face, equilibrium and non-equilibrium model, equilibrium model is suitable for high pressure sealing medium ( Usually refers to the pressure is greater than 1. 0MPa) , double end face machine is mainly used for high temperature, easy to crystallization, viscosity, and toxic volatile medium including particle, double end face machine sealing should be added spacer to the sealed cavity, the pressure is generally higher than that of medium pressure 0. 7 ~ 0. 1MPa。