It seems ironic that an o ring, a simple, moulded, doughnut shaped part made of a single material could warrant so much attention. Because they are relatively inexpensive and very reliable they are one of the most commonly used products in sealing applications.
Also known as a packing, or a toric joint, it is a mechanical gasket in the shape of a torus. A loop of elastomer with a round cross-section. It is designed to be seated in a groove and compressed between two or more parts. this creates a seal at the interface.
The selection of a specific O Ring is based on a wide variety of factors that include:
There have been so many significant advances in materials over the years, but often the best solution is the simplest. Click the picture below for further information on these wonders of engineering.