The maximum surface roughness value, Rmax, is the most important factor that affects the life span of the sealing elements in pneumatic systems. Surface roughness values should be according to the catalogue information provided in the each product group.
Rz value that we indicate in our catologue is the average of the 5 consecutive maximumum roughness values in specific length of surface, Rmax is the maximum of these values and Rp is the height of the surface roughness (Figure 24).
We recommend Rmax value not to be higher than the value given in our catologue and Rp/Rz ratio to be less than 0.5. Surface contact area Rmr ratio is also an important factor in the surface roughness.