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In the use of desulfurization centrifugal pumps and other chemical processing equipment, leaks often occur as a result of failure in the mechanical seal of the centrifugal pump. There are many different types of mechanical seals, each with its own specifications. When installing such pumps, different types of seals are chosen depending on the operating conditions and requirements. What are the reasons for seal leakage? Where are the main points of leakage? ① The seal between the shaft sleeve and the shaft； ②Sealing between the rotating ring and the shaft sleeve ； ③Seal between rotating and stationary rings ； ④Sealing between the stationary ring and the stationary ring seat ； ⑤Sealing between the sealed end cover and the pump body. 1. The failure of the sealing rings in mechanical seals is also a major cause of seal leakage; the sealing rings of the rotating and stationary parts are installed at an incorrect angle ； The surface finish of the shaft or sleeve that fits with the sealing ring is insufficient, or the fit dimensions are too small ； Physical or chemical reactions between the sealing ring and the sealing medium, as well as corrosion, deformation, aging, etc., can all lead to leaks. 2. Improper assembly leads to leakage in the mechanical seal. Before assembling the mechanical seal, the components are not cleaned properly, or they are damaged or scratched ； Improper assembly ； The spring is misaligned and the fastening screws are not tightened ； Damage during disassembly, etc., are all causes of premature failure of mechanical seals. 3. Leakage of mechanical seals caused by improper selection and design. Due to the variety in the properties of the process media used in chemical plants, improper design of mechanical seals can result in an insufficient or excessive pressure on the sealing surfaces, or in significant cold shrinkage of the sealing materials; all of these factors can easily lead to the failure of the mechanical seals and subsequent leakage. 4. Wear of the end faces of the stationary and rotating rings leads to leakage in mechanical seals. For any type of mechanical seal, its main characteristic is that the sealing surfaces are end faces perpendicular to the axis of rotation; this transforms what would otherwise be an axially oriented seal prone to leakage into an end-face seal that is less likely to leak. Therefore, the main form of failure in mechanical seals is wear failure between the stationary and rotating rings. The friction pair at the end faces of the rotating and stationary rings is primarily compressed by spring force to prevent leakage. The tighter the compression between the moving and stationary rings, the less likely leakage is to occur; however, the friction between them also increases. Under such high friction, the mirror-like surfaces at the contact points of the moving and stationary rings wear out quickly, leading to failure and leakage. 5. Unstable process conditions and poor installation lead to mechanical seal leakage. Vibration caused by unstable process conditions and poor installation, as well as sudden interruptions in flow during the vaporization of the fluid inside the equipment, can all result in the breakdown of the liquid film between the stationary and rotating rings of the mechanical seal. This causes the mechanical seal to operate in a \"dry\" condition without any lubrication; as a result, the temperature of the sealing rings rises rapidly. In some cases, the seals get burned out, while in other cases they are suddenly cooled down once the pump returns to normal operation, leading to thermal shock and damage to the seals. Poor flushing fluid and flushing conditions can also cause thermal shock, leading to radial cracks in the sealing ring and exacerbating wear failure of the stationary and rotating rings. At the same time, when the graphite ring exceeds its operating temperature, crystals form on its surface; carbonization occurs in the vicinity of the friction pairs at higher temperatures, and these particles enter the friction pairs, causing rapid wear and failure of both the moving and stationary rings.