standard seals Seal material
The seal is a material or part that prevents the fluid or solid particles from leaking from adjacent joints and prevents external contaminants such as dust and moisture from entering the interior of the machine.
(1) select the appropriate seal material and hydraulic oil, as well as the adaptability to the working temperature, the compatibility of the oil.
(2) Geometric position of the sliding parts relative to the seal (concentricity) High material (eg hard chrome plated) and fine surface roughness to extend service life.
① For hydraulic pumps, the oil seal used in the journal journal not only requires the roughness of the sliding surface to be within 0.25m of Ra, but also requires hard chrome plating on its surface. In the specific use, it is necessary to adjust the diameter of the oil seal lip To the spring force to make it moderate, but also in the installation with a mounting sleeve or thin gasket to protect the seal, so as not to pull the tongue roll, twisted, causing the spring to slide out.
② hydraulic cylinder cylinder surface rolling method commonly used, not only to improve the surface roughness, but also to the surface of the cold hardening treatment, is conducive to extend the life of the seal ring. In addition, the use of pressure, sliding surface length and type of life also have a great impact. Therefore, it should be based on these conditions to determine the "check" time.
③ require sealing surface lubrication in good condition to prevent the invasion of dirt. It is also necessary to use the oil and the correct installation method to achieve the required cleaning level.
Mechanical seal selection common sense and use - mechanical seals are precision, the structure is more complex mechanical foundation components, is a variety of mechanical seals pump, reaction reactor, turbine compressor, submersible motor and other equipment key part. The sealing performance and service life depend on many factors, such as selection, machine accuracy, proper installation and so on.
First, the selection method
Mechanical seal according to the working conditions and the nature of the medium, there are high temperature, low temperature mechanical seal, high pressure, corrosion resistant mechanical seal, resistant to granular media
Sealed and adapted to vaporize the mechanical seal of light hydrocarbon media, etc., should be based on different uses to select different structural types and mechanical seal of the material.
The main parameters of the selection are: sealed chamber pressure (MPA), fluid temperature (℃), working speed (M / S), fluid mechanical seal characteristics and the installation of sealed
The basic principles of selection are:
1. According to the sealing chamber pressure, to determine the sealing structure using balanced or non-balanced type, single-ended or double-ended and so on.
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, to determine the friction and auxiliary sealing material, and the correct choice of lubrication, washing, insulation, cooling and other mechanical seal cycle protection
System and so on.
4. According to the installation of the effective space of the seal, to determine the use of multi-spring or single spring or wave spring, built-in or exterior type.