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Material characteristics of dynamic and static seal

Update:2018-07-18

As an indispensable important part of the rubber seal diaphragm in the mechanical seal, the choice of sealing material can greatly improve the sealing performance of the mechanical hydraulic seal in operation, stability and the service life of the seal. 

The main effects of sealing materials have been found to be in hardness compatibility, stiffness (elastic modulus), strength, toughness, self-lubricity, thermal properties (such as expansion, thermal conductivity), density, high and low temperature resistance, and chemical resistance, tribological properties, pu values and the permeability of the seal, it will directly affect the "sealing effect".

First, the "thermal performance" of the sealing material performance of the rubber sealing film dynamic and static seal

Thermal performance - The expansion coefficient is an important parameter for the thermal gradient of the sealing surface caused by the temperature gradient, and is also a very important parameter for the thermal shock resistance of the sealing material. 

The thermal conductivity is critical for the heat generated by the friction at the sealing interface to conduct the cooling liquid, the low coefficient of expansion minimizes thermal shock, and the high thermal conductivity minimizes the temperature gradient. 

Temperature gradients and thermal shocks can cause thermal stress cracking or thermal fatigue cracking. For example, the heat capacity is important for the effect of transient heating on thermal stress and is available when determining mechanical seal flushing.

Second, the "density" of the sealing material performance of the rubber sealing film dynamic and static seal

Density - It is one of the important factors influencing the sealing dynamics during eccentricity or yaw, and is also important in the stress induced by centrifugal effects. The low density of the rotating ring reduces inertia and balance problems.

Third, the "resistance temperature performance" of the sealing material performance of the rubber sealing film dynamic and static seal

Resistance to temperature performance - resistance to friction and high ambient temperatures without distortion or loss of mechanical properties.

Fourth, the "resistance to chemical properties" of the sealing material performance of the rubber sealing film dynamic and static seal

Resistance to chemical properties - chemical compatibility with fluids and any impurities present at operating temperatures needs to be checked