The O ring is one of the most successful seal designs in the world and it is also one of the most simple. It is basically a torus or donut shaped piece of rubber or other materials which is used to form a physical barrier to prevent the loss of gas or fluid.
O rings are used in all types of industry for all kinds of sealing applications including aerospace, chemical processing, pharmaceuticals, marine, food and dairy and medical requirements to name just a small selection.
O rings come in a range of standard and non standard sizes. They are measured across their inside diameter and sit in a corresponding groove. To calculate the right size of O ring for any given application it is useful to use an o ring size chart to make selection accurate and easy. There are a number of free size charts on the websites of O ring manufacturers and suppliers.
O rings also come in a wide range of materials each with unique properties and performance. High performance materials would be chosen in areas such as food and medical industries, aerospace, oil and gas and chemical industries. This is because they have an excellent resistance to high temperatures, high pressures and attack from aggressive chemicals.