VITON O-RINGS

VITON-O-RINGSThis sealing model, the O-Ring, was born in 1882 from an intuition of Thomas Alva Edison, when he used for the first time a similar gasket in a water-cock patent, after the study of Pascal’s Law of Hydrostatics. This affirms that pressure exerted in any point of a confined fluid is spread over the liquid, in all directions and in an equal way. The outbreak of O-Rings application began in 1930, with the discovery by DuPont of synthetic rubber, which was put on the market 4 years later. Thanks to their high degree of diffusion, International Standard Organization issued the Norm ISO 3601, which regulates this particular type of sealing, especially for what concerns the dimensional tolerances for the 2 fundamental sizes, internal diameter and thickness, and the maximum dimension of visual aspect defects.

Together with their outstanding sealing properties, they also have a simple manufacturing process, they are easy to mount, both manually and automatically, even though they do not require large housings. As regards this point, it is worth to talk about the permanent deformation resistance, also known as hardness. In fact, the choice of this value can be made on a range, which goes from about 30 up to 95/100 IRHD. Lower hardnesses grant more adaptable parts, but lower pressure resistance, while higher hardnesses require very smooth housing surfaces, but guarantee a very high resistance to fluid pressure (e.g. 90 IRHD O-Rings are used for Anti-Explosive Decompression applications). Standard hardnesses are 70, as regards static applications, and 75, for what concerns dynamic applications; normally, colour black has the highest performances, due to the presence of dark fillers, and for this, it is considered as standard.

O-Rings manufactured with Viton ® fluoroelastomers are commonly used to create sealing force in contact with aggressive mediums, like gasoline or diesel, at high temperatures.

They can also be used for extreme low temperatures and anti-explosion decompression applications: these gaskets are manufactured with a very strong grade of FKM and are usually employed, respectively, in contact with e.g. liquid nitrogen and in petroleum extraction plants.