Mechanical seal for pump

Maintenance of mechanical seals for pumps: There are five main leakage points of mechanical seals for pumps: (l) the seal between the shaft sleeve and the shaft. (2) the seal between the moving ring and the shaft sleeve. (3) moving, The seal between the static ring. (4) The seal between the static ring and the static ring seat. (5) The seal between the sealing end cover and the pump body. Generally speaking, the sealing end cover and the pump body are between the extended shaft of the shaft sleeve. It is easier to find and solve the leakage in the middle, but it needs careful observation, especially when the working medium is liquefied gas or high pressure, toxic and harmful gas, it is relatively difficult. The rest of the leakage is intuitively difficult to distinguish and judge, and it must be managed in the long-term On the basis of maintenance practice, the correct conclusion can be drawn only by observing, analyzing and judging the leakage symptoms. Misunderstandings in the maintenance of mechanical seals for pumps: 1. The greater the compression of the spring, the better the sealing effect. In fact, if the compression of the spring is too large, it can cause rapid wear of the friction pair and instantaneous burn. 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 moving ring seal, the better. In fact, the too tight of the moving ring seal is harmful and useless. One is to aggravate the wear between the seal 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. When the working conditions change frequently, it cannot be adjusted in time. The third is that the spring is excessively fatigued and easily damaged. The fourth is to deform the moving ring sealing ring, which 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 relatively tight sealing effect will be better, but too tight is also harmful. The first is that the static ring seal is excessively deformed and affects the sealing effect. The second is static. The ring material is mostly graphite, which is generally brittle, and excessive force is very easy to cause chipping. Third, it is difficult to install and disassemble, and it is easy to damage the static ring. 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 more common. It is generally believed that the leakage between the shafts means that the impeller lock nut is not locked, which actually leads to leakage between the shafts. There are many factors, such as failure of the pad between the shafts, offset, impurities in the shaft, large shape and position error at the matching place of the shaft and the shaft sleeve, damage to the contact surface, gaps between the components on the shaft, and the thread of the shaft head Long waits will cause leakage between the shafts. Excessive locking of the lock nut will only cause premature failure of the inter-axis pad. On the contrary, the lock nut shall be properly locked so that the inter-axis pad always maintains a certain degree of compression elasticity. The lock nut will automatically lock in time during operation. Tight, so that the shaft is always in a good sealing state.