Misconceptions about repairing mechanical seals

In many cases, in the maintenance of mechanical seals will exist to the next few misconceptions: 

1, the greater the amount of spring tightening sealing effect is better. In fact, not, taut spring constriction is too large, can lead to sharp wear and tear of the friction side, the moment burned; excessive tightening so that the taut spring lost the ability to regulate the moving ring end face, resulting in sealing failure. 

2, the tighter the moving ring seal, the better. In fact, the moving ring seal ring is too tight harmful. One is to aggravate the wear between the seal and the sleeve, premature leakage; two is to increase the dynamic ring axial adjustment, moving resistance, in the working conditions change frequently can not be adjusted when the order; three is the excessive fatigue of the taut spring easy to damage; four is to make the dynamic ring seal deformation, affecting the sealing effect. 

3, the tighter the static ring seal the better. Static ring seal ring is simply in a stop condition, relatively tight seal effect will be better, but too tight is also harmful. First, the static ring seals due to excessive deformation, affecting the sealing effect; Second, the static ring material to graphite mostly, generally more brittle, excessive force is easy to cause shattering; Third, the device, disassembly difficult, easy to damage the static ring. 

4, the tighter the impeller lock mother the better. Mechanical seals seal leakage, the leakage between the sleeve and the shaft (shaft leakage) is more common. Generally thought that the shaft leakage is impeller lock mother did not lock tight, in fact, resulting in more factors between the shaft leakage, such as the shaft pad failure, offset, impurities in the shaft, shaft and sleeve cooperation at a large deformation error, touch surface damage, the shaft between the parts of the gap, the shaft head thread is too long, etc. will lead to shaft leakage. Locking mother locking excessive will only lead to premature failure of the inter-shaft pad, on the contrary moderate locking closed mother, so that the inter-shaft pad has been adhering to a certain tight elasticity, in the operation of the locking mother will take the initiative to lock in order to make the inter-shaft has been in a prominent sealing condition. 

5, the new better than the old. Relatively speaking, the use of new mechanical seals seal better than the old, but the new mechanical seals seal quality or material selection is not its time, cooperation scale error will affect the sealing effect; in the polymeric and permeable media, static ring such as no excessive wear, still not replaced for good. Because the static ring in the static ring seat for a long time in the stop condition, so that the polymer and impurities deposited as one, played a better sealing effect.