Did you know that the Space Shuttle Challenger disaster in 1986 could have been prevented if the engineers used proper o-rings?
You might be wondering, “what is an o-ring?” The short answer is that an o-ring is one of the most widely used sealing devices. It’s even better than duct tape, imagine that!
What does the o-ring have to do with the crash of the Challenger? How does it factor into the destruction of the shuttle 73 seconds into the flight which killed all seven crew members?
During that tragic day, there was cold weather before launch. The material of the o-rings, which was FKM, wasn’t equipped to handle the unusually cold temperature. The o-rings failed, allowing high-temperature gas to escape and the subsequent break down of the right solid rocket booster.
Want to learn more about the o-ring? Then please continue reading below.
What Is an O-Ring?
The o-ring is a mechanical gasket in the shape of, well, a ring. Well, not exactly a ring, but, to be more precise, the shape is a torus. It looks like a donuts, the type with a hole in the middle.
As we’ve mentioned, the material that makes up the o-ring is of extreme importance. It’s usually made of synthetic rubbers, such as nitrile and silicone.
Material selection depends on the application it’s used for. It’s based on chemical and temperature compatibility, size, cost, and other factors.
For example, FKM or fluoroelastomer used in the Challenger would have been perfect for rocket flying. It’s heat resistant, durable and long-lasting. However, the engineers didn’t take into account that it can become brittle and lose its elasticity in cold temperatures.
Because of the incident, o-ring manufacturing underwent significant changes. These include awareness of proper o-ring design and rigorous batch-testing for quality control.
You can find o-rings everywhere, on anything that requires a seal. These include pumps, valves, cylinders, and connectors. They’re present in equipment used in the oil and gas industries, food processing, and even toy manufacturing.
How Does It Work?
Despite its very basic design, an o-ring can withstand thousands of PSI of pressure. How does it do that?
In the simplest terms, the o-ring sits in a groove or channel between two parts that are going to be pushed together. As the second hardware component is pressed into the first one, the o-ring becomes compressed, forming a seal between the two surfaces. At rest or zero pressure, the natural resiliency of the material of the o-ring prevents any attempt at escape by the fluid inside the chamber.
What happens when the pressure rises inside the sealed system? The o-ring will be pushed to the opposite side of the pressure. The elastic property of the o-ring material allows it to deform, essentially forming a plug and increasing the strength of the seal.
When the pressure is released, the o-ring will return to its original shape, thus maintaining the integrity of the seal.
O-Ring Any Bells?
The o-ring is a simple gadget that’s been put to work in various applications because of its ability to form a powerful seal. “What is an o-ring and how does it work?” We hope that this article has answered those questions.
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