The double-end mechanical seal is a device that prevents fluid leakage by keeping the end surface (friction pair) perpendicular to the rotation axis under the action of the fluid pressure and the elastic force of the compensation mechanism and the cooperation of the auxiliary seal to keep fit and relatively slide. There is one more friction pair than the single mechanical seal. The two friction pairs can be composed of two moving rings and two static rings respectively, or two moving rings sharing one static ring or two static rings sharing one moving ring.
The installation steps and precautions of double-end mechanical seals are as follows:
1. First clean the rotating shaft and sealing cavity.
2. During the installation process, the double-end mechanical seal device should be kept clean, especially the surface of the sealing surface and the auxiliary sealing ring should be free of impurities and dust. It is not allowed to wipe the sealing surface with unclean cloth and other items.
3. Apply lubricating oil or soap solution to all the installation O-rings in the double-end mechanical seal device (note: the ethylene-propylene rubber material should not be in contact with mineral oil) to facilitate the smooth installation of the mechanical seal.
4. During installation, attention should be paid to distinguish the installation direction of the left and right static rings and the shaft sleeve. When installing a double-end mechanical seal that prevents axial displacement of the static ring, the snap ring must be placed in the corresponding position of the seal cavity.
5. It is strictly forbidden to collide and savagely beat the sealing element during installation to prevent damage to the double-end mechanical seal. The friction surface should be kept clean without any oil.
6. After the double-end mechanical seal is installed, turn the rotary shaft by hand to check whether there is friction between the static ring, the gland and the shaft sleeve, and between the rotating part and the sealing chamber. The pump shaft should feel evenly applied when it rotates one circle. If it cannot be rotated or the local force is very large after one turn, check whether the seal has installation problems. If necessary, the pump should be dismantled to find the problem, and then reinstall it after solving it.