Pump Parts-The difference between external and internal machine seals
1. Appearance
2. Installation location
External mechanical seal refers to a mechanical seal installed outside the shaft end of the equipment, usually located outside the equipment and connected to the main body of the equipment through flanges or other connection methods.
The internal machine seal is a mechanical seal directly embedded inside the equipment, usually located inside the equipment and closely cooperating with the rotating parts of the equipment.
3. Structure and composition
The structure of the external machine seal is relatively simple, usually composed of a moving ring, a stationary ring, a spring, a sealing ring, and a transmission mechanism.
The structure of the internal machine seal is more complex and may require consideration of more factors, such as the internal structure of the equipment, the size and shape of the shaft, etc. Usually includes dynamic ring components, static ring components, elastic elements, auxiliary sealing rings, and fasteners.
4. Performance and Application
External machine seals are suitable for various pump equipment, such as centrifugal pumps, axial flow pumps, etc. When dealing with corrosive media, special attention should be paid to the selection of materials to prevent corrosion.
Internal machine seals are more suitable for equipment operating at high pressure, high temperature, or high speed, such as compressors, mixers, etc. The design of the internal machine seal is more compact, which can reduce the possibility of leakage and improve the reliability of the equipment. Due to its complex structure and difficult maintenance, it is necessary to fully consider the operating conditions and lifespan requirements of the equipment when selecting.
5. Maintenance and replacement
The maintenance of external machine seals is relatively simple, usually by disassembling the flange to inspect or replace the seals.
The maintenance of internal machine seals is relatively complex, usually requiring the dismantling of part or all of the equipment structure for inspection or replacement. Replacement requires higher technical expertise and longer repair time, resulting in relatively higher costs.
