One of the external factors that affect the effectiveness of mechanical seals is poor machining accuracy

There are many reasons for the insufficient machining accuracy of mechanical seals, some of which are due to the insufficient machining accuracy of the mechanical seals themselves. These reasons are easy to attract people's attention and are also easy to find. But sometimes the machining accuracy of other components of the pump is insufficient, which is not easy to attract people's attention. For example, due to insufficient precision in enlarging the pump shaft, shaft sleeve, pump body, and sealing chamber. The existence of these reasons is very detrimental to the sealing effect of mechanical seals.

2. External factors affecting the effectiveness of mechanical seals: excessive vibration

The mechanical seal vibrates excessively, ultimately leading to the loss of sealing effect. However, the reason for the excessive vibration of mechanical seals is often not due to the mechanical seal itself. Other components of the pump are the root cause of vibration, such as unreasonable pump shaft design, processing reasons, insufficient bearing accuracy, poor parallelism of couplings, and large radial forces.

3. External factors affecting the effectiveness of mechanical seals: large axial displacement of the pump shaft

The sealing surface of a mechanical seal must have a certain specific pressure in order to achieve a sealing effect. This requires the spring of the mechanical seal to have a certain compression amount, giving the mechanical seal end face a thrust and rotating it to produce the required specific pressure for sealing. In order to ensure this specific pressure, the mechanical seal requires that the pump shaft should not have too much displacement. The mechanical seal cannot withstand axial force during use, and if there is axial force, it will have a serious impact on the mechanical seal. Sometimes, due to the unreasonable design of the axial force balancing mechanism of the pump and reasons related to manufacturing, installation, and use, the axial force is not balanced. Mechanical seals bear an axial force, and during operation, the temperature of the sealing gland will be higher. For polypropylene media, they will be melted at high temperatures, so the sealing effect will quickly lose after the pump is started. When the pump is stationary, there will be intermittent leakage at the sealing end face.

4. External factors affecting the effectiveness of mechanical seals: lack of auxiliary flushing system or unreasonable setting of auxiliary flushing system

The auxiliary flushing system of mechanical seals is very important. The auxiliary flushing system of mechanical seals can effectively protect the sealing surface, playing a role in cooling, lubricating, and washing away debris. Sometimes designers fail to properly configure auxiliary flushing systems and fail to achieve sealing effects; Sometimes, although designers have designed auxiliary systems, the sealing effect cannot be achieved due to impurities in the flushing liquid, insufficient flow and pressure of the flushing liquid, and unreasonable design of the flushing port position.