The difference between oil seal and water seal

Number of hits：6282023-05-28 17:40:53　

　　Oil seal and water seal are two common types of mechanical seals, which are devices that prevent the leakage of working medium by forming a tight contact between two smooth and flat surfaces perpendicular to the shaft and rotating relatively. However, oil seal and water seal have some significant differences in their structure, function and principle.

　　The main difference is that water seal is used to seal water, while oil seal can seal both water and oil. Water seal is suitable for low-pressure and low-temperature applications, such as water pumps, faucets, etc. Oil seal is suitable for high-pressure and high-temperature applications, such as engines, compressors, turbines, etc.

　　Another difference is that oil seal and water seal have different sealing principles. Oil seal relies on the oil film controlled by the oil seal lip to prevent the leakage of working medium. The oil film has fluid lubrication characteristics, and under the action of liquid surface tension, it forms a crescent surface at the contact end with air, thus achieving the sealing of the rotating shaft. Water seal relies on the hydrodynamic pressure generated by the relative rotation of the sealing surfaces to form a thin layer of water film between them, thus achieving the sealing effect.