Mechanical seal use precautions
Mechanical seals are common wearing parts of water pumps, but they will be more likely to cause mechanical seal wear and leakage if used or installed improperly. What factors will affect the life of mechanical seals?
First, the axial force is too large. Mechanical seals cannot withstand axial forces during use. If axial forces are present, the effect on mechanical seals is severe. Sometimes the axial force is not balanced due to the unreasonable design of the axial force balance mechanism of the pump and the manufacturing, installation, and use reasons. Second, the mechanical seal is subjected to an axial force, and the temperature of the sealing gland will be high during operation. The polypropylene medium will melt at a high temperature, so the sealing effect will be lost soon after the pump starts. The sealing end face will appear when the pump is stationary—intermittent leaks.
Second, the deflection of the pump shaft is too large. Mechanical seal, also known as an end face seal, is a rotary axial contact type dynamic seal. Under the action of a fluid medium and an elastic element, two sealing end faces perpendicular to the axis line are closely fitted and relatively rotated, thereby achieving The sealing effect requires a uniform force between the two seals. However, due to the unreasonable design of the pump product, when the pump shaft is running, the deflection generated at the mechanical seal installation is large so that the force between the sealing surfaces is uneven, resulting in a poor sealing effect.
Third, the vibration is too large. The mechanical seal vibration is too large, eventually leading to the loss of sealing effect. However, the reason for the large vibration of the mechanical seal is often not the cause of the mechanical seal itself. Other parts of the pump are the source of vibration, such as unreasonable pump shaft design, processing reasons, insufficient bearing precision, and poor parallelism of the coupling. Radial force and other reasons.