Six major problems in pump sealing and overhaul

1, the new is better than the old one

Relatively speaking, the effect of using a new mechanical seal is better than that of the old one, but the quality or material selection of the new mechanical seal is not appropriate. The large dimensional error will affect the sealing effect; in the polymerizable and permeable medium, the static ring is not excessive. Wear or not replace it as well. Because the static ring is in a static state for a long time in the static ring seat, the polymer and impurities are deposited as one body, which has a good sealing effect.

2, the total repair is better than not disassembled, once the mechanical seal leaks, it is eager to repair, in fact, sometimes the seal is not damaged, just adjust the working conditions or adjust the seal properly to eliminate the leak. In this way, it avoids waste and can verify its own fault judgment ability, and accumulates maintenance experience to improve the quality of maintenance.
3, the tighter the seal diagram of the moving ring, the better the moving ring seal is too harmful and harmful. First, the wear between the seal ring and the bushing is intensified, and the leakage is premature. Secondly, the resistance of the axial adjustment and movement of the moving ring is increased. When the working condition changes frequently, the adjustment cannot be timely; thirdly, the spring is excessively fatigued and easily damaged; It is to deform the moving ring seal and affect the sealing effect.
4, the tighter the ring seal is better. The static ring seal is basically in a static state, the relatively tight sealing effect will be better, but too tight is also harmful. First, the static ring seal is caused by excessive deformation, which affects the sealing effect. Secondly, the static ring material is mostly graphite, which is generally brittle. Excessive force is easy to cause fragmentation. Third, it is difficult to install and disassemble, and it is easy to damage the static ring.
5. The tighter the impeller lock is, the better the mechanical seal leaks. The leakage between the bushing and the shaft (axial leakage) is more common. It is generally believed that the leakage between the shafts is that the impeller locks are not locked. In fact, there are many factors causing leakage between the shafts, such as the failure of the inter-axis pads, the offset, the impurities between the shafts, and the larger shape of the shaft and the sleeve. The position error, the contact surface is broken, there is a gap between the components on the shaft, and the shaft thread is too long, which causes leakage between the shafts. Excessive locking of the lock nut will only lead to premature failure of the inter-axis pad. On the contrary, the lock nut is moderately locked, so that the inter-shaft pad always maintains a certain compression elasticity. During operation, the lock nut will automatically lock in time, so that the shaft is always in good condition. Sealed state.
6, the greater the amount of spring compression, the better the sealing effect. In fact, the amount of spring compression is too large, which can cause the friction pair to wear sharply and burn out instantly; excessive compression causes the spring to lose the ability to adjust the end face of the moving ring, resulting in seal failure.