Beyond the Seal: Why Material Science, Testing, and Ingenuity Matter More Than Ever
by Courtney Rau, Business Development Manager, ODIN Heavy Industries
I’ve spent a lot of years in “valve circles,” and if there’s one thing I’ve learned, it’s this:
Sealing isn’t simple anymore.
What used to be a straightforward O-ring selection has turned into a deeply engineered decision that can impact uptime, emissions, safety, and total cost of ownership. The environments we’re sealing against are harsher. The tolerances are tighter. The expectations are higher.
And in many cases, failure isn’t dramatic — it’s incremental. A little compression set. A little chemical swelling. A little leakage that turns into a big problem later.
That’s why the conversation has to move beyond “what seal fits?” to:
What material system is truly engineered for this application — and has it been validated?
Elastomers vs. Thermoplastics — It’s Not Either/Or
Two primary material families dominate our world: elastomers and thermoplastics. Both are critical. Both are powerful. And both have limitations.
Understanding when — and how — to use them is where engineering makes the difference.
Elastomers: Flexible, Responsive, and Pressure-Activated
Elastomers are what most people think of first — rubber-like materials that deform under load and recover when the load is removed.
They are excellent at:
-Conforming to surfaces
-Absorbing vibration
-Providing sealing force in low to moderate pressure systems
-Handling dynamic movement
Materials like HNBR, FKM, FFKM, EPDM, and Aflas® all have their place — but they are not magic. Under extreme pressure, aggressive chemistry, or high temperature cycling, elastomers can experience compression set, extrusion, or degradation.
They’re often the right starting point. But rarely the whole answer.
Thermoplastics: Structural Strength and Chemical Backbone
Thermoplastics bring rigidity and chemical resilience to the equation.
Materials like PTFE, PEEK, PCTFE, and engineered composites provide:
-Dimensional stability
-Wear resistance
-Superior chemical compatibility
-Structural support under high pressure
They don’t provide the same elastic sealing force as elastomers — but they shine where extrusion resistance and structural integrity are critical.
The Reality: Modern Sealing Is a System
In today’s industrial applications, the best solutions are rarely single-material.
We’re seeing more engineered combinations:
● Elastomer O-ring for sealing force
● Thermoplastic backup ring for extrusion control
●Wear-resistant polymer components for dynamic interfaces
Sealing has become a material system — not just a part number in a catalog.
And selecting that system requires more than intuition. It requires engineering discipline and validation.