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6 Steps To Find Out The Cause of Mechanical Seal Leakage of Chemical Centrifugal Pump

Learn - Sep. 07, 2022

mechanical seal of chemical pump

The chemical pump is an important equipment in chemical plant. For bad working conditions, the mechanical seals of chemical pumps are easy to be disturbed, leading to the failure of sealing, then affecting the progress of chemical production. When the pump handles toxic, volatile, flammable, explosive liquid, the leakage will cause serious consequences, we should ensure the reliable operation of the mechanical seal to prevent leakage.

The failure of mechanical seal of chemical pump, usually come from three aspects: mechanical damage, corrosion damage and thermal damage, but because of the special structure of the mechanical seal, its work environment is complex, therefore, in fact, the form of mechanical seal damage is more diverse. We summarized the chemical pump operation of the mechanical seal leakage of the most common six reasons, find the reason for the chemical pump mechanical seal leakage, in practical application, avoid these factors, can effectively prevent the chemical pump mechanical seal leakage, is beneficial to prolong the service life of the chemical pump.

6 common chemical pump mechanical seal leakage causes are as follows:

Step one    Step two    Step three    Step four    Step five    Step six

Step one:Pump model selection is not appropriate

If there is no selection according to the actual needs of the chemical pump work, it will lead to the end pressure of the mechanical seal is too large or too small. When the pressure on the end face is too large, it is not conducive to the formation of the liquid film between the friction pair, resulting in excessive friction between the end faces, and then lead to serious wear, resulting in deformation of the seal, resulting in leakage; When the end pressure is too small, the friction between the end faces can not be timely and effective compensation, because the friction force is too small, in the process of work will lead to skid, is not conducive to the normal work of the pump.

Step two:The material of the sealing ring is not correct

Engineers in choosing a sealing ring, to pump working environment, nature of work, the pressure and the rotation of the rotor speed and other factors make a comprehensive consideration, choose the correct seal materials, otherwise easy to cause seal material cannot pump to meet the demand of the work, can't have good sealing effect, caused by sealing ring greatly shorten service life

Step three:The pressure

Only sufficient pressure can ensure the realization of mechanical seal of chemical pump. In the assembly process of chemical pump, if the spring is not effectively compressed in strict accordance with the prescribed model, and the pressure is not enough, it may lead to the occurrence of a large difference. And then affect the sealing effect of chemical pump. In order to ensure uniform force on each end face of chemical pump, we can make full use of materials with high compressive strength such as cemented carbide to reduce displacement.

Step four:Periodic leakage

In the process of chemical pump operation, due to its own pump running characteristics, when the pump rotor axial momentum and periodic vibration is large, will cause adverse to the smooth running of the pump, the influence of the interference of the auxiliary seal and shaft quantity increases gradually, the increase as the amount of interference, cause the ring cannot be conducted on axis flexible mobile, As a result, the mechanical seal of the pump fails, causing the leakage of the surrounding.

Step five:External Factors

First, the axial channeling momentum of the pump is relatively large. The realization of the mechanical seal of the chemical pump is based on the sealing surface bearing a certain specific pressure. Usually, the channeling momentum of the pump shaft of the chemical pump is less than 0.5mm. Second, pump with mechanical seal vibration range is larger. If the vibration amplitude of mechanical seal of chemical pump is too large, it will cause the failure of mechanical seal. The reason for the large vibration amplitude of chemical pump is that the design of the pump is unreasonable, the radial force is too large, the bearing accuracy is not enough, the parallelism of the coupling is not enough and so on.

Step six:The worker did not operate correctly

During the operation of the chemical pump, due to cavitation and evacuation, the axial force of the chemical pump is large, and then the end face of the moving ring and the static ring are separated.

In the assembly process of the chemical pump, workers did not install the mechanical seal correctly, resulting in the expansion of the pump is too large, resulting in the wear of the end face of the friction pair.

During installation, the pump's moving ring seal ring is too close, resulting in the spring can not automatically adjust the floating amount of the moving ring axial, at this time, if the static ring seal ring is too loose, once the moving ring axial floating, the static ring may be detached from the static ring seat. Once the particles in the medium enter the friction pair of the dynamic and static rings, it will cause damage to the end seat of the dynamic ring seal and the static ring seal.