1 pump shaft axial channeling large

　　2 axial force is too large

　　The mechanical seal during use are not able to withstand the axial forces, axial force, the influence of the mechanical seal is a serious.

　　Sometimes unreasonable pump axial force balance mechanism design and manufacture, installation, use of reason, causing axial force is not balanced. Mechanical seal to withstand an axial force, the operation when the temperature of the gland to high for the medium of the polypropylene type, at high temperatures will be melted, so pump starts soon after the loss of the sealing effect, and the pump is stationary seal faces appear intermittent spray leakage phenomenon.

　　3 shaft deflection is too large

　　Mechanical seals, also known as seal, movable seal is a rotary axial direction of the touch, it is in the fluid medium and the role of the elastic element, the seal faces of the two perpendicular to the axis line closely bonded, relative rotation, so as to achieve The sealing effect, thus requiring force uniform between the two seals. However, due to the the pump product design unreasonable, the operation of the pump shaft, mechanical seal installed at larger deflection discontinuity, between the sealing surface of the cause poor sealing effect.

　　4 no auxiliary flushing system or auxiliary flushing system set unreasonable

　　Secondary flushing system of the mechanical seal is very important, and it can effectively protect the sealing surface, and serves to cool, lubricate and carry away debris, and other effects. Sometimes designers no reasonable auxiliary flushing system is configured to reach the sealing effect; sometimes designers auxiliary system design, but due to impurities in the washing fluid, the flow of irrigation fluid pressure is not enough, rinse mouth position unreasonable design reasons , also reach the sealing effect.

　　5 vibration is too large

　　The mechanical seals vibration is too large, and ultimately result in the loss of the sealing effect. The large mechanical seal vibration because more often than not the reasons of the mechanical seal, the other parts of the pump generates the source of the vibration, shaft design unreasonable processing, bearing accuracy is not enough, the coupling of parallelism, radial force and other reasons.

　　6 reasons for pump cavitation

　　Bad because of the the device system operating unreasonable and cavitation performance of the pump inlet, the high speed of the pump, in the entrance of the pump the local cavitation, cavitation occurs, there will be bubbles in the water, it will, on the one hand, the impact of mechanical sealing surface The outer surface, its surface appears damaged; the other hand, causes the movement ring anastomosis surface flow membrane containing bubbles, can not form a stable flow of film, resulting in a dry friction of the surface of the static ring anastomosis, so that damage to the mechanical seal device.

　　7 machining accuracy is not enough

　　Machining accuracy is not enough, there are many reasons, and some mechanical seals itself machining accuracy is not enough, the reasons for this is easy to attract attention, but also easy to find.

　　But sometimes it is not enough, the machining accuracy of the other parts of the pump and in this regard it is not easy to attract attention. For example: shaft, bushings, pump seal cavity to increase the accuracy is not enough reason. The existence of these reasons the sealing effect of the mechanical seal is very unfavorable.