2. Relative tightness

The arrangement of two surfaces resting on each other, even with considerable effort, only leads to a relative seal. Indeed, any surface will have manufacturing defects, shape defects (or macro-defects), and surface defects proper (micro-defects or roughness) [R 1 230] . Attempting to limit the number of these defects always increases the price of the parts, sometimes considerably. What's more, there's never any guarantee of completely eliminating these defects, which are the source of leaks that may be very small but measurable. What's more, although two surfaces are statically joined, they undergo relative...