What are the installation suggestions and preparations for mechanical seals?

What are the installation suggestions and preparations for mechanical seals?

Preparations before installation and installation precautions Check whether the model and specification of the mechanical seal to be installed are correct and whether the quality meets the standard. Check whether the components of the mechanical seal are damaged, especially whether the sealing end faces of the moving ring and the static ring are bumped. If any damage is found, the mechanical seal must be repaired or replaced with new parts. Each sealing element needs to be cleaned with gasoline or kerosene to keep the surface of each element free of dust and foreign matter. Check whether there are burrs, groove marks, etc. on the surface of the shaft or the shaft sleeve of the submerged sewage pump, the inner wall of the sealing cavity, and the inner surface of the sealing end cover. If burrs and groove marks are found, they should be smoothed, polished, and cleaned with gasoline or kerosene to keep them clean, and no dust and debris are allowed to adhere to the surface. Do not use dirty cloth or cotton gauze on the mechanical seal to scrub the surfaces of the moving ring and stationary ring, but use a clean and soft gauze, absorbent cotton and the like. During the assembly process, it should be kept clean to ensure that the sealing end faces of the moving ring and the static ring are not scratched or broken. In order to facilitate installation, oil should be smeared on the surface of the shaft or bushing, the mating surface of the gland and the sealing ring, and the sealing end faces of the moving ring and the static ring should also be smeared with oil to avoid dry friction at the moment of startup. The impregnated graphite ring should be hydrostatically tested before installation, the hydrostatic pressure should not be less than 1.5~2.5 times of the working pressure, and the outer surface of the graphite ring should not appear water droplets and sweating. If the above experimental conditions are not available, the assembly static pressure test can be carried out after the sealing installation and before the pump is started to identify the pressure resistance of the graphite ring. An axial clearance of 1~2mm should be maintained between the end of the anti-rotation groove at the end of the static ring and the top of the anti-rotation pin to avoid buffer failure. When installing the mechanical seal with the spring structure, pay attention to the rotation direction of the spring should be the same as the rotation direction of the shaft. If the direction is wrong, the seal will fail. For example, the 103-type mechanical seal with single-spring structure is divided into two types: left-handed and right-handed. During installation, special attention should be paid to the different spring rotation directions of the mechanical seals at the front and rear of the pump. If the rotation direction of the pump shaft is ignored during installation, the mechanical seal is likely to be installed backwards, making the front and rear mechanical seals ineffective. The piping system connected to the equipment must also be cleaned. If the sundries in the system are not cleaned up in time, after long-term operation, sundries may enter the seal, thus affecting the life of the seal. Most of the premature failure of the new equipment seal is caused by this reason, so it is necessary to set a filter at the inlet before the new equipment is started.