Selection Methods and Basic Principles of Mechanical Seal

Mechanical seals are one of the precise and complicated mechanical elements, which are the key parts of various pumps. For the pump, more than 50% of the leakage problem is often caused by mechanical seal!

According to different working conditions and media properties, there are mechanical seals with high temperature resistance and low temperature resistance, with high pressure resistance and corrosion resistance, and mechanical seals resistant to particle media and suitable for light hydrocarbon medium which is easy to vaporize. Mechanical seals of different types of construction and materials shall be selected for different purposes. Selection of main parameters are: seal cavity pressure (MPa), fluid temperature (℃), the working speed (m/s), the characteristics of the fluid and install sealed effective space, etc.

Basic principles of type selection

1. According to the pressure of the sealed cavity, determine whether the sealing structure is balanced or non-balanced, single end face or double end face, etc.

2. According to the working speed, determine the use of rotary or static, fluid dynamic pressure type or non-contact type.

3. According to the temperature and fluid properties, determine the friction pair and auxiliary sealing materials, and correctly choose lubrication, washing, heat preservation, cooling and other mechanical seal cycle protection system.

4. According to the effective space of sealing installation, multiple or single spring or corrugated spring, internal or external type is adopted.