Precautions for the use of pump mechanical seals

The following matters should be paid attention to when using mechanical seals of pumps:

Many people think that it is better to disassemble and repair the mechanical seal than not to disassemble it. When the seal leaks, it is hurriedly disassembled and repaired. In many cases, the seal is not damaged. Just a little tweaking of the seals can fix the leak and avoid unnecessary waste.

The static ring seal of the mechanical seal should not be too tight. Although it is in a static state, too tight will also cause excessive deformation, and the sealing effect is not good. Some static ring seals are made of graphite. The material is relatively brittle and tightened with excessive force, which is prone to breakage, and is also extremely easy to be damaged during installation and disassembly. It is recommended to use some imported seals to have a longer service life.

The tightness of the moving ring seal in the mechanical seal should be moderate. If the moving ring seal is too tight, the friction will increase, which will accelerate the wear between the moving ring seal and the shaft sleeve and cause premature leakage. . Increase the axial adjustment of the moving ring and the resistance during movement. In the case of frequently changing operating conditions, there is no way to make appropriate adjustments. The spring will also be too tight, resulting in serious fatigue failure or even damage, and it is easy to cause serious deformation of the moving ring sealing ring, and the sealing effect is not good.

The spring in the mechanical seal should be compressed in a moderate range. It must not be considered that the greater the compression range of the spring, the better the sealing effect. In fact, this is not the case. If the spring is compressed too much, the friction will be greatly increased. If it increases, the seal will be seriously worn or even burned out. Excessive compression of the spring will easily lose the adjustment ability of the end face of the moving ring, which will directly cause the seal to fail.

The impeller lock nut in the mechanical seal should not be too tight. In common leaks, there will be more leakage between the shaft and the shaft sleeve. This is not only the reason why the impeller lock nut is not locked, other Many factors can cause leakage, such as deformation, offset, failure of the gasket between the shafts, impurities mixed in the end face of the shaft, a relatively large error in shape and position between the sleeve and the shaft, the contact surface is damaged, and the various components on the shaft interact with each other. There is a gap between them, the thread of the shaft head is too long, etc., which will lead to leakage between the shafts. Many cases are similar to the leakage of hydraulic seals.