Views: 4654 Author: Site Editor Publish Time: 2020-05-26 Origin: Site
Mechanical seals have been widely used in petrochemical and other industrial sectors due to their good sealing properties and long service life. However, accidents often occur if mechanical seals are improperly installed and poorly maintained. Mechanical seals are relatively sophisticated Components, so correct installation procedures, strict operating specifications, and reasonable maintenance systems are powerful measures to ensure mechanical seal performance and normal operation. What should be paid attention to when selecting and installing mechanical seal?
Identifying the exact liquid being handled is the first step in the seal selection process. Seal material must be able to withstand the fluid being processed. All seal materials must be chemically compatible with the fluid, or there is an increased risk of seal failure.
Pressure in the seal chamber and seal size determines the type of seal required, balanced or unbalanced.
Seal materials must be selected to appropriately handle the liquid’s temperature. Temperature is important because different seal materials are rated for certain temperatures and you should not exceed the temperature limit of these materials.
Knowing the viscosity of the liquid is important to ensure appropriate seal life. Abrasive liquids can create excessive wear and will ultimately shorten the seal's life. Double seals or use of an external flush plan give operator's the option to use mechanical seals on these difficult fluids.
Every company has their own standards and operating procedures when it comes to reliability and emission concerns for an application. The seal type and arrangement selected must meet the desired reliability and emission standards for the pump application. Since environmental safety has become a hot topic among manufacturing companies, double seals are peaking as the solution of choice.
1. The radial runout of the rotating shaft of the equipment should be less than 0.04 mm, and the axial movement amount is not allowed to be greater than 0.1 mm.
2. The sealing parts of the equipment shall be kept clean during installation. The sealing end face shall be intact to prevent impurities and dust from entering the sealing parts.
3. It is forbidden to bump or knock during the installation process, so as to avoid the double mechanical seal friction pair damage and seal failure.
4. During the installation, the surface in contact with the seal should be coated with a layer of clean mechanical oil to facilitate smooth installation.
5. When installing the static ring gland, the screws must be evenly tightened to ensure the vertical requirements of the end face of the static ring and the axis line.
6. After installation, push the moving ring by hand to make it move flexibly on the shaft and have certain elasticity.
7. The equipment must be filled with medium before operation to prevent seal failure due to friction.
After the mechanical seal is installed, move the ring by hand to ensure flexible rotation. For the mechanical seal of important equipment (such as water pump mechanical seal), static pressure test and dynamic pressure test must be carried out, and it can be put into formal use only after passing the test.