VITON GASKETS

VITON-GASKETSO-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. ISO Norm 3601 regulates this type of sealing; it establishes standard sizes and the related tolerances; it also decrees a formula by which it is possible to calculate tolerances of non-standard O-Rings. They have a high quality of the finish and can be employed both for axial and radial seal. This model was born more than 100 years ago, in 1882, when Thomas Alva Edison registered an O-Ring as gas sealing in a water-cock patent. Other licenses for the use of O-Rings were issued in 1930 in North America. Over these years, synthetic rubber was discovered and started its development: thanks to this revolution, O-Rings began their successful application increase. Rubbers have the same behaviour of a highly viscous fluid: according to Law of Hydrostatics of Blaise Pascal, pressure exerted on them is spread at the same degree in all directions. Basically, the pressure of the fluid to be retained reinforces both the radial and the axial forces generated by the sealing housing: in this way, the higher is the fluid pressure, the higher is the sealing force. Furthermore their outstanding sealing qualities, O-Rings are also simple to mould, easy to mount and maintain and do not require large housings. Hardness is another crucial point: in fact it depends on the type of housing and the fluid pressure: the more you need O-Rings that adapt better and easily to the surface structure of contact surfaces and the fluid pressure is shallow, the lower the hardness must be and vice versa. Most common hardness values are 60, 70, 80 and 90 IRHD. Moreover, especially for dynamic applications, the most used O-Rings have a hardness grade of 75 IRHD.

Viton ® gaskets can be employed for the most various applications, among which we can cite the contact with aggressive fluids at high temperatures, like diesel or gasoline. Pressurization has no effect and cause no reaction on polymers: videlicet, compression is fundamental to create seal. For this reason, fluoroelastomers have also good compression set characteristics: this property regards a high temperature test, usually at 150/200°C, under crushing, which can give a theoretical demonstration of the sealing capability of the O-Ring under these strenuous conditions.