Leak-free is the eternal pursuit of chemical equipment, and it is this requirement for pumping mechanical seals to promote the increasing application of magnetic pumps. However, there is still a long way to go to truly achieve no leakage, such as the life of the magnetic pump isolation sleeve, the pitting corrosion of the material, the reliability of the static seal, and so on. Some basic information about sealing is briefly introduced as follows:
1. For static seals, there are usually only two types of seals and seals, and O-rings are the most widely used seals; for dynamic seals, chemical pumps rarely use packing seals, and mechanical seals are the main ones. , Mechanical seals are divided into single end face and double end face, balanced type and unbalanced type. The balanced type is suitable for the sealing of high-pressure media in the mechanical seal of the kettle (usually the pressure is greater than 1.0MPa). The double end face mechanical seal is mainly used for high temperature, For the medium that is easy to crystallize, has viscosity, contains particles, and is toxic and volatile, the double-end machine seal should inject isolating liquid into the sealed cavity, and its pressure is generally higher than the medium pressure by 0.07~0.1MPa.
2. Sealing material Chemical magnetic pump static seal material is generally fluorine rubber, and PTFE material is used in special circumstances; the material configuration of mechanical seal dynamic and static ring is more critical, not cemented carbide is the best to cemented carbide, and the price is high. On the one hand, there is no difference in hardness between the two and it is unreasonable, so it is best to treat them differently according to the characteristics of the medium.