PTFE vs Rubber Gaskets: Which is Better for Your Flange?

Ever had a flange leak ruin your day? Yeah, me too – back when I was troubleshooting setups in chemical plants, a bad gasket choice meant downtime, cleanup, and a lot of swearing under my breath. Choosing between PTFE vs rubber gaskets isn’t just about grabbing whatever’s cheapest on the shelf. It’s about what actually holds up when things get hot, corrosive, or just plain demanding.

I’ve spent years working with these materials hands-on, testing them in real piping systems, and talking to engineers who live and breathe this stuff. At Teflon X, we focus on high-performance PTFE solutions, but I’ll give you the straight scoop on both sides – no fluff. Let’s dig into the differences so you can figure out what’s truly the best value for your setup.

What Exactly Are PTFE Gaskets Anyway?

PTFE – you probably know it as Teflon – is that slick, almost nothing-sticks-to-it plastic. In gasket form, it’s usually sheets cut to fit flanges, sometimes expanded (ePTFE) for better compressibility.

The big draws? It laughs at most chemicals and handles crazy temperatures. Reliable sources like gasket manufacturers and engineering guides list virgin PTFE’s operating range around -200°C to +260°C (-328°F to 500°F). That’s why you’ll see it everywhere from pharma lines to aggressive acid piping.

It’s got super low friction too, which means easier bolt-up and less chance of galling on flanges. Downside is it’s not as squishy as rubber, so you need proper compression and sometimes filled versions (with glass or other stuff) to make it seal better on imperfect surfaces.

We’ve cut and supplied tons of these at Teflon X, including our chemical-resistant PTFE gasket sheets that hold up where others fail fast.

Rubber Gaskets – The Everyday Workhorses

Rubber gaskets cover a huge family – EPDM, Viton, nitrile, neoprene, you name it. They’re elastomers, so they bounce back and fill gaps really well.

Common ones for flanges:

• EPDM: Great with water, steam, mild acids. Temp range typically -50°C to +150°C.
• Viton (FKM): Loves oils, fuels, harsher chemicals. Usually good from -20°C to +200°C or a bit more.

Rubber seals tight on rougher flanges because it compresses nicely and recovers. They’re cheaper upfront and easier to source in standard sizes.

But they do have limits – petroleum stuff eats some rubbers alive, and high heat makes them harden or crack over time.

Head-to-Head: Temperature Resistance

Temperature is usually the first knockout punch.

PTFE wins easy here. Data from multiple engineering sources shows it stable up to 260°C continuous, with short spikes even higher. Rubber? EPDM tops out around 150°C before it starts degrading, Viton pushes to 200°C but still falls short of PTFE’s extreme range.

In one setup I saw, a plant switched from Viton to PTFE on a 220°C steam flange – leaks stopped, and the gaskets lasted years longer.

If your process runs hot or cycles a lot, PTFE saves you headaches.

Chemical Compatibility – Where Things Get Interesting

This is PTFE’s home turf.

PTFE resists almost everything – acids, bases, solvents, you name it. Only a couple exotic things like molten alkali metals or certain fluorine gases attack it.

Rubber varies wildly:

• EPDM handles water, glycols, mild acids great but swells horribly in oils.
• Viton does better with hydrocarbons and stronger chemicals, but still not as universal as PTFE.

Looking at chemical resistance charts from manufacturers like IPEX or Mykin, PTFE gets “excellent” across way more columns than any rubber.

For corrosive flanges, PTFE is often the safer long-term bet.

Quick Aside: PTFE vs EPDM

People ask about PTFE vs EPDM a lot because both get used in water and milder chems. EPDM is cheaper and seals easier on low-pressure stuff, but once you hit stronger acids or higher temps, PTFE pulls ahead big time. We’ve seen EPDM swell and fail in dilute sulfuric lines where our PTFE sheets just kept going.

And What About Viton vs PTFE Gasket?

Viton vs PTFE gasket debates come up in oil and fuel systems. Viton resists petroleum beautifully and costs less than PTFE, but if you’ve got really aggressive solvents or super high heat, PTFE edges it out. Viton can harden over time in extreme conditions, while PTFE stays inert.

Compression, Recovery, and Actual Sealing Performance

Rubber shines here – it’s elastic, fills surface imperfections, and recovers when bolts relax a bit.

PTFE is stiffer and creeps more under load (that’s the cold flow thing everyone mentions). But modern expanded or filled PTFE fixes a lot of that, giving good recovery without being too soft.

In practice, proper torque and clean flanges make either work, but rubber forgives sloppy surfaces better.

Cost and Longevity – The Real Money Talk

Rubber wins on sticker price, no question. A basic EPDM gasket might cost half or less what PTFE does.

But flip it around to total cost: PTFE often lasts way longer in tough environments. One example from sealing industry discussions – elastomer seals needing replacement every 6 months vs PTFE going 5 years. Do the math on downtime, labor, and lost product, and PTFE frequently comes out cheaper overall.

At Teflon X, customers tell us switching to our PTFE sheets cut their gasket spend by 30-40% over a couple years because they weren’t replacing them constantly.

Side-by-Side Comparison Table

Here’s a quick table pulling from real material data sheets and engineering guides:

Property	PTFE (Virgin/Expanded)	EPDM Rubber	Viton (FKM) Rubber
Temperature Range	-200°C to +260°C	-50°C to +150°C	-20°C to +200°C+
Chemical Resistance	Excellent (nearly universal)	Good for water/acids, poor for oils	Excellent for oils/fuels, fair for strong acids
Compression/Recovery	Fair to Good (better with filled)	Excellent	Very Good
Cost (relative)	Higher upfront	Lower	Medium to Higher
Longevity in Harsh Conditions	Excellent	Fair	Good
Common Flange Uses	Chemical, pharma, high-temp	Water, steam, weather	Oil, fuel, automotive

Real-World Applications I’ve Seen

In a food plant, they used EPDM on sanitary flanges – worked fine until cleaning chemicals got stronger, then leaks started. Switched to PTFE envelopes and problem solved.

Another case: refinery using Viton on hydrocarbon flanges. Held up okay, but when temps spiked during upset conditions, hardening caused failures. PTFE upgrade fixed it and reduced maintenance stops.

One chemical processor we helped had mixed acids eating through rubber fast. Our PTFE sheets went in and they’re still running years later with zero issues.

These aren’t made-up stories – patterns we see all the time when people move to better materials.

When Rubber Actually Makes Sense

Don’t get me wrong, rubber has its place. Low-temp, low-pressure water lines? Mild environments? Go rubber and save the budget for something else.

Outdoor weathering, ozone exposure – EPDM is king there.

Just know the limits so you don’t pay later.

When PTFE Is Clearly the Better Choice

Aggressive chemicals, wide temp swings, or where failure costs big money – PTFE all the way.

The upfront cost hurts less when you factor in years of reliable sealing.

FAQ

Wrapping This Up

So, PTFE vs rubber gaskets for your flange? It boils down to your specific conditions and what “better” means to you – cheap now or reliable longer.

From everything I’ve seen (and fixed), PTFE gives the best overall value when things aren’t gentle. It costs more upfront, sure, but pays back in peace of mind and fewer emergencies.

If you’re still unsure about your setup, drop us a line. We’ve helped tons of folks figure out the smartest choice and get the right material shipped fast.

Reach out anytime at https://teflonx.com/contact-us/ or email Allison.Ye@teflonx.com for quotes or questions. We’ll sort you out with no pressure – just straight answers.