1) pressure
The level of pressure, the length of the pressure cycle cycle changes, the seal damage (such as extrusion) have a great impact. The higher the pressure, the greater the impact of other factors on the performance of the seal, such as temperature, speed, seal material, clearance between the piston and cylinder, and the clearance between the piston and the cylinder head.
2) temperature
It is difficult to describe the maximum operating temperature and minimum operating temperature of a seal material because it is the result of a series of factors. For the piston and piston rod operating temperature is different, to distinguish between them to choose.
3) Friction
The friction of the seal and the sealing surface depends on many factors: surface roughness, surface characteristics, pressure, medium, temperature, seal material, seal type and speed of movement.
4) Surface treatment
Experience has shown that the characteristics of the cylinder piston and piston rod surface have a very large impact on the life of the seal. The surface characteristic is usually defined by the value of the surface roughness Ra, Ra is the arithmetic mean of the absolute value of the surface shape deviating from the centerline. But this value does not fully represent the effect of the surface condition on the seal, because even at the same roughness, different surface shape features can result in different levels of sealing of the seal.