Understanding the Extreme Challenges of Sealing for Cryogenics

Sometimes, the smallest things make the biggest difference. Even in the most extreme fields full of complex challenges, it is still often the simplest things that stand in the way.

Exhibit A: seals and o-rings. Most people will go their whole lives without ever thinking about these items. But the design, materials, and innovations involved in this seemingly straightforward technology are absolutely critical for so many industries.

From space exploration and fuel compression to cryogenics and specialty gas manufacturing, seals and o-rings prove how vital they are every single day.

When Disaster Strikes

Something this small really can become a matter of life or death. Most infamously, the Space Shuttle Challenger disaster was the result of unseasonably cold weather in Florida causing a large, but simple o-ring to fail in the rocket booster during liftoff.

Beyond the human tragedy of the lives lost, this catastrophic oversight has become a case study for engineers across the world as well as an MBA lesson for what can go wrong in organizational culture and group decision-making processes. The saga has been analyzed and second-guessed for decades, including in the book “Truth, Lies, and O-Rings” by Allan J. McDonald, former director of the Space Shuttle Solid Motor Rocket Project for Morton-Thiokol, Inc., the outside firm that designed the rocket booster for the shuttle.

Thankfully, most sealing applications are not literally rocket science and they do not end in calamity. Nevertheless, this will forever highlight that o-rings help to make the world go around in ways that most of us will never realize.

Sealing at Extreme Temperatures

The effect of temperature on sealing is something that engineers still grapple with to this day. Few areas understand this better than the world of cryogenics. While executives and professionals in sales or marketing may feel like they can leave these concerns up to the wonks who design the systems, it still pays for everyone involved in related sectors to recognize where these challenges lie.

For cryogenics, dealing with low temperatures is core to the whole business. So there is no room for failure or guessing games when it comes to keeping everything running properly.

So it is essential to have seals and o-rings in all devices and in all applications that are up to the task. Not only do they have to be able to operate at incredibly low temperatures and withstand intense pressure, but the material must be resilient and durable enough to regularly confront extreme temperature fluctuations without breaking down over time or failing suddenly.

Seal Materials and Applications

In general, higher-quality materials make for higher-quality o-rings and seals. For example, Viton silicone o-rings have outstanding chemical resistance and high-temperature resistance. In many ways, they could be considered the ideal material to use.

But no one compound is perfect for all use cases. Different applications will always require materials with different properties. If you need flexible sealing components that will remain effective under extreme temperature changes, silicone may be the only viable solution.

By contrast, there are many more great options — including fluorocarbon, ethylene-propylene, and even natural rubber — if the applications will only confront typical ambient temperatures in the range from around 0 degrees Fahrenheit to 100 degrees Fahrenheit.

Performance in Harsh Conditions

Seal and o-rings are much more critical than most people will ever realize. This plays out in some areas more than others, especially those involving extreme temperatures.

When it comes to cryogenics, companies are becoming more and more innovative every day. Sealing, though it may seem secondary, will always have a major role to play in the process. And the more that companies can confidently rely on the seals used within these applications, the easier it will turn their focus from a few small components to the big picture.