Selection method and use requirements of mechanical seal Mechanical seal

Selection method and use requirements of mechanical seal

2021-07-08 11:03

Selection method:

The main parameters of mechanical seal selection: seal cavity pressure (MPA), fluid temperature (°C), working speed (M/S), fluid characteristics, and useful space for sealing, etc. According to the difference in working conditions and medium properties, mechanical seals include high temperature resistant and low temperature resistant mechanical seals, high pressure resistant and corrosion resistant mechanical seals, mechanical seals resistant to granular media and mechanical seals suitable for light hydrocarbon media that are easy to vaporize, etc. The function of selecting different structural types and materials of mechanical seals.

The basic criteria for selection are:

1: According to the pressure of the sealing cavity, determine whether the sealing structure adopts uniform or non-uniform type, single end face or double end face, etc.

2: According to the working speed, determine the use of rotary or static, hydrodynamic or non-contact type.

3: According to the temperature and fluid properties, determine the materials of the friction pair and auxiliary seals, and correctly select the mechanical seal cycle protection systems such as lubrication, flushing, heat preservation, and cooling, etc.

4: According to the effective space of the installation seal, it is determined to use multiple springs or single springs or wave springs, built-in or external.

Installation and application requirements of mechanical seals:

1: Requirements of mechanical seals for machine precision (taking mechanical seals for pumps as an example)

(1) The radial runout of the shaft (or shaft sleeve) where the mechanical seal is placed is very small and does not exceed 0:04~0:06MM.

(2) The axial movement of the rotor does not exceed 0:3MM.

(3) The runout of the positioning end of the sealing cavity and the sealing end cover to the surface of the shaft (or sleeve) is very small and does not exceed 0:04~0:06MM.