Applied pressure puts strain on parts and cause frictional heat to both seal faces.
The temperature of processed media affects the liquid film as well as seals materials.
The shaft speed will affect the liquid film as well as frictional heat.
Shaft seal materials will affect the function and lifetime of mechanical seals.
Therefore it's important to consider friction, wear and corrosion resistance during seal design.
Legislation, directives, standards, guidelines, etc., may all have to be met.