泵用机械密封：叶轮锁母越紧越好。机械密封泄漏中，轴套与轴之间的泄漏（轴间泄漏）是比较常见的。一般认为，轴间泄漏就是叶轮锁母没锁紧，其实导致轴间泄漏的因素较多，如轴间垫失效，偏移，轴间内有杂质，轴与轴套配合处有较大的形位误差，接触面破坏，轴上各部件间有间隙，轴头螺纹过长等都会导致轴间泄漏。锁母锁紧过度只会导致轴间垫过早失效，相反适度锁紧锁母，使轴间垫始终保持一定的压缩弹性，在运转中锁母会自动适时锁紧，使轴间始终处于良好的密封状态。
Mechanical seal for pump: the tighter the impeller lock nut, the better. In the leakage of mechanical seal, the leakage between shaft sleeve and shaft is common. It is generally believed that the inter shaft leakage is that the impeller lock nut is not locked tightly, in fact, there are many factors that cause the inter shaft leakage, such as the failure and deviation of the inter shaft gasket, impurities in the inter shaft, large form and position errors in the fit between the shaft and the shaft sleeve, the damage of the contact surface, the gap between the components on the shaft, the too long thread of the shaft head, etc., which will lead to the inter shaft leakage. Excessive locking of the lock nut will only lead to premature failure of the inter shaft gasket. On the contrary, moderately locking the lock nut will keep a certain compression elasticity of the inter shaft gasket. During operation, the lock nut will lock automatically and timely, so that the inter shaft gasket will always be in a good sealing state.