FVMQ-O-RINGSO-Ring is the most commonly used model of gasket in the world. These articles are circular cross-section rings, identified by two main dimensions: thickness and inside diameter. They are regulated by the international norm ISO 3601: it decrees standard sizes for this kind of article and their tolerances; from this standard, it is also possible to extrapolate tolerances of non-conventional-sized O-Rings. They have a high degree of the finish and can assure both radial and axial seal. O-Ring sealings are more than 100 years old: in fact they have been registered in 1882 by Thomas Alva Edison, as gas sealing rings in a water-cock patent. Other patents for the use of these parts were granted in North America in 1930, but it was only with the discovery of synthetic rubber in the 30’s, that O-Rings began their successful growth. Fluorosilicones behave like highly viscous fluids: pressure exerted on them is propagated to practically the same degree in all directions (Law of Hydrostatics, Blaise Pascal). The axial and radial forces generated by the sealing housing are bolstered by the pressure of the fluid to be held. The total sealing force created in this way, grows as the pressure of the fluid rises. In addition to their excellent sealing properties, O-Rings are simple to produce, easy to mount (manually and automatically), do not require much maintenance and large housings. On the basis of the type of housing, another crucial point is the hardness: the lower is this value, the more the O-Rings adapt more easily and better to the surface structure of the contact surfaces. Instead, the more the fluid pressure rises, the more it is necessary to have a smooth housing surface and use a compound with a higher degree of hardness. Most common hardnesses are goes from 60 to 90 IRHD, but the standard one is 70; furthermore, as regards dynamic applications, the most used O-Rings have a hardness degree of 75 IRHD.

FVMQ gaskets can be used for the most diverse applications, among which we can mention the contact, at low temperatures, especially with ozone, but they also have good resistance against oils and permanent deformation caused by mechanical forces.