O-rings are a very common feature in most types of industrial applications. Put simply, O-rings are nothing more than solid or flexible seals that are usually from rubber and are shaped like a doughnut. The most common usage of O-rings in our daily lives is the rings that are used in pressure cookers. Obviously, industrial grade O-rings are designed to be more powerful and sturdier compared to their domestic counterparts. The primary function of these rings is to prevent the seepage of liquids and gases. To that end, these rings can form static or dynamic seals. Static functions of an O-ring would be to maintain a certain pressure level whereas a dynamic seal would be in the case of a piston.
The two most widely used methods for applying O-rings to an industrial surface are axial squeeze and radial squeeze. O-rings are available in a wide array of dimensions and configurations depending upon the industrial usage and application for which it is needed.
An O-ring is generally flexible as it made to be bent out of shape. These devices work by placing them between two components and then compressing them to form an airtight seal between the objects. The O-ring's flexibility enables it to mold into the space it is fitted in. As it flexes and reshapes itself it pushes into any spaces, cavities and cracks and fills them in. The seal will remain in place as long as the pressure of the gas or liquid doesn’t exceed the contact point of the ring and its contact surfaces. Some types of O-rings are made to enough to withstand thousands of pounds per square inch (PSI) of pressure.
O-rings were invented in 1936 by a Danish man and his invention and patent were then purchased by the US government. Many types of O-rings were used during the Second World War. Even though O rings may be small and inexpensive items, they can often be essential to the performance of the devices they are placed in. In 1986, the American space shuttle Challenger met with a disastrous end as the O-rings failed to do their job and the spacecraft blew up and disintegrated in mid air just 73 seconds after it had blasted off. All seven astronauts were killed.