Replacement of mechanical seal is very necessary, but we should pay attention to the following several misconceptions.
1. The greater the amount of spring compression replacement of mechanical seal is not sealed the better the results.Because of large amount of spring compression, which can lead to sharp wear and friction pair friction plate instantaneous loss;Excessive compression spring lose the ability of adjusting ring end face, lead to seal failure.
2. The ring seal the tighter, the better.Actually ring seal tight more harm than good.One is the wear between seal and shaft sleeve, prematurely leak;2 it is to increase the axial adjustment, mobile, the resistance of the ring in working condition changes frequently unable to timely adjust;3 it is spring fatigue damage easily;Four is to make the ring seal deformation, affect the sealing effect.
3. The static seal tight, the better.Static ring sealing ring in static state, the basic relatively tight sealing effect will be better, but too tight is also harmful.One is the cause of excessive static ring seal for deformation, affect the sealing effect;Second, if the static ring material is graphite, generally brittle, excessive stress can easily cause fracture;Three is to install and remove the difficult and easy to damage the static ring.
4. Impeller fixed screw tight, the better.Mechanical seal leakage, the sleeve and the shaft leakage between (axial leakage) is relatively common.Is generally believed that the leakage of the shaft between the impeller lock the mother didn't lock, actually lead to leakage of the shaft between many factors, such as axial failure, migration, contains impurities between shaft, shaft and shaft sleeve with larger shape error, contact surface damage, shaft have clearance between components, shaft thread is too long can lead to leakage between shaft.Mother lock lock will only cause axial mat premature failure, on the contrary moderate lock to lock the mother, the shaft between the mat keeps certain compression elasticity, lock the mother in operation will automatically lock timely, remain the state of good sealing between the shaft.
5. The new is better than the old.Relatively, the effect of using new mechanical seal is better than the old, but the quality of the new mechanical seal or material choose not to at that time, cooperate with size error is meeting influence sealing effect;In polymerized and medium permeability, and the static ring without excessive wear, or not to change as well.Because the static ring in static ring long time in the stationary state, make the polymer and the sediment is an organic whole, played a good sealing effect.