1.The larger the spring compression, the better the sealing effect. In fact, if the spring compression is too large, it can cause the friction pair to wear rapidly and instantaneously burn out; excessive compression makes the spring lose the ability to adjust the end face of the moving ring, resulting in seal failure.
2.The tighter the sealing diagram of the moving ring, the better. In fact, too tight a dynamic ring seal is harmful and useless. One is to aggravate the wear between the sealing ring and the shaft sleeve, and to leak prematurely; the other is to increase the resistance of the axial adjustment and movement of the moving ring, which cannot be adjusted in time when the working conditions change frequently; the third is that the spring is easily damaged due to excessive fatigue; It deforms the moving ring sealing ring and affects the sealing effect.
3.The tighter the static ring seal, the better. The static ring seal is basically in a static state, and the sealing effect will be better if it is relatively tight, but too tight is also harmful. The first is that the static ring seal is excessively deformed, which affects the sealing effect; the second is that the static ring is mostly made of graphite, which is generally brittle, and excessive stress can easily cause fragmentation; the third is that it is difficult to install and disassemble, and the static ring is easily damaged.
4.The tighter the impeller lock nut, the better. In mechanical seal leakage, the leakage between the sleeve and the shaft (inter-shaft leakage) is relatively common. It is generally believed that the leakage between the shafts means that the impeller lock nut is not locked. In fact, there are many factors that cause the leakage between the shafts, such as the failure of the shaft pads, offsets, impurities in the shafts, and large shapes in the matching parts of the shafts and sleeves. Position errors, damage to the contact surface, gaps between parts on the shaft, and excessively long shaft head threads will cause leakage between the shafts. Over-locking of the lock nut will only cause premature failure of the inter-axis pad. On the contrary, properly lock the lock nut so that the inter-axis pad always maintains a certain compression elasticity. During operation, the lock nut will be automatically locked in time, so that the shafts are always in good condition. The sealed state.
5.The new one is better than the old one. Relatively speaking, the effect of using the new mechanical seal is better than the old one, but the quality or material of the new mechanical seal is not properly selected, and the large size error of the fit will affect the sealing effect; in the polymerizable and permeable media, the static ring is not excessive. Worn, it is better not to replace. Because the static ring stays in a static state for a long time in the static ring seat, the polymer and impurities are deposited as a whole, which has a better sealing effect.
6.It is better to dismantle and repair than not to dismantle. Once the mechanical seal leakage occurs, it is eager to dismantle and repair. In fact, sometimes the seal is not damaged, and the leakage can be eliminated by adjusting the working conditions or properly adjusting the seal. This can not only avoid waste but also verify one's own fault judgment ability, accumulate maintenance experience and improve the quality of maintenance.