Precautions On Installation And Removing Of Mechanical Seal

Between the spindles, between the gland and the body, the leakage of the centrifugal pump seals seriously affects the working efficiency of the pump, which increases the frequency of maintenance of the centrifugal pump and increases the consumption of equipment spare parts. Therefore, in order to improve the service life of the machine, there are several points to pay attention to during the inspection.

1. Precautions when removing

When removing the mechanical seal, it is forbidden to use the hand hammer and spade blade to avoid damaging the sealing element. If there are mechanical seals on both sides of the pump, care must be taken during disassembly to prevent misconduct.

For working mechanical seals, if the sealing surface moves when the gland is loose, the static and dynamic ring parts should be replaced and should not be used again. Because the original running track of the friction pair will change after loosening, the sealing of the contact surface will be easily damaged. If the sealing element is contaminated by dirt or condensate, the condensate should be removed and the mechanical seal removed.

2. Precautions during installation

Before installation, check carefully whether the number of sealing parts is sufficient. Whether the components are damaged, in particular, there are defects such as bumps and deformations in the moving and static rings. If there is a problem, repairs or replacement of new spare parts are required. Check whether the chamfer of the sleeve or gland is proper. If it does not meet the requirements, it must be trimmed.

Mechanical seal components and their associated assembly contact surfaces must be cleaned with acetone or anhydrous live finish before installation. The installation process should be kept clean, especially the moving and static rings and auxiliary sealing elements should be free from impurities and dust. Apply a layer of clean motor oil or turbine oil to the surfaces of the moving and stationary rings.

The upper gland should be adjusted after the coupling is aligned. The bolts should be tightened evenly to prevent deflection of the cover section. Check the points with a feeler gauge or special tool. The error is <0.05 mm.

Check the gap (and the coaxiality) of the gland and the outer diameter of the shaft or bushing. It must be ensured that the circumference is even. Check the tolerance of each point with the feeler gauge <0.Imm.

The amount of compression of the bullet tube should be carried out according to the regulations. It is not allowed to have too large or too small phenomenon, and the error soil is required to be 2mm. The excessive wear of the cross-section of the pressure-accelerated section is exceeded. Too small will cause insufficient specific pressure and can not play a sealing role. After the spring is installed, it must move flexibly in the spring seat. When using a single spring, pay attention to the direction of rotation of the spring. The rotation of the spring should be opposite to the direction of rotation of the shaft.

After the ring is installed, it must remain flexible to move. After the ring is pressed against the spring, it should spring back automatically. After the static ring seal is placed on the back of the stationary ring, it is installed in the sealed end cap. Pay attention to the protection of the stationary ring section, ensure the verticality of the section of the stationary ring and the center line of the end cap, and align the rotation prevention slots on the back of the stationary ring with the anti-rotation pins, but do not allow them to contact each other.

During the installation process, it is not allowed to use the tool to directly hit the sealing element. When it is necessary to knock, special tools must be used to knock in order to prevent damage to the sealing element.