Do I Need an O-ring or a Gasket?

How well do you understand the differences between o-rings and gaskets? Can you readily identify situations where each type of seal should be used? There are specific situations where each technology is needed because they are designed for completely different conditions.

Today, we thought we’d dig a little deeper into gasket vs. o-ring.

Gasket vs. O-ring

What exactly is an o-ring?

If you are envisioning a rubber ring, you are right! However, they aren’t quite that simple. An O-ring is a precisely molded shape with a specific profile to fit into a specific channel or groove. These profiles can be various shapes and the polymer (type of rubber) can also vary greatly. Infinite formulas can be made to address specific sealing situations.

Where and how are they used?

O-rings are known for their ability to seal extremely high pressures. Here is a short list of some of the more common places where you would find them.

    • Hydraulic seals
    • Pipe joints
    • Fluid seal points in equipment
    • Oil seals
    • Fuel systems

How does this differ from gaskets?

When you move away from engineered seals like o-rings, the next technology to use in the sealing family is a gasket. These typically require a flat flange and a bolted joint. Gaskets are by far the most versatile seal, with different shapes, materials, coatings, methods, etc. Depending on the type of material chosen, they can seal at a wide range of temperatures and pressures. Composite (metal reinforced) materials provide some of the strongest heat and pressure resistance (as far as gaskets go) in the market today. For more information about these materials, view our post What Is a Metal Reinforced Gasket and Why Do I Need One?

How do gaskets with rings compare to an o-ring?

Some of you may know that adding a ring to your gasket design adds another layer of protection against increased pressure. Rings make a good gasket even stronger. View our post Should I Put a Ring On It? (Your Gasket, That Is) to get a better understanding of this technology. In light of our discussion today regarding o-rings, the next logical question is how does a gasket with a ring compare to an o-ring? The simple answer is that the O-ring requires a channel or groove in the flanges, while a gasket can perform with a simpler, flat flange. O-rings are typically used when pressures are higher, with the channel present to prevent blowout.

Choose Your Technology

Once you truly understand all of the engineering behind all of the various sealing technologies, the decision on what should be used is very clear. Until then, talk to your contacts in the sealing industry to better understand what your options are for a specific application.

Until next time!Hi-Tex Product Comparison

Exhaust Leak? Here Are Some Things To Investigate.

Troubleshooting an issue? Some of you probably live for the task, others of you never want to hear those words again. It isn’t an activity that is for the faint of heart. It can be incredibly frustrating at times, but when you finally resolve the issue, you are ready to take on the world…especially if the issue has consumed your life for an extended period of time.

When you’re dealing with an exhaust leak, the issue could be a number of things, and it isn’t necessarily the fault of your gasket or gasket material. Keep on reading for things to investigate during your troubleshooting.

The Investigation

1. There could be a problem with the design

Check to see if the joint is loaded sufficiently and not distorting. This could send you back to the drawing board unless you are able to find a gasket material that can compensate for the design deficiencies.

2. At the same time, check for loading issues

Is the load distributed properly and evenly? If not, hopefully it is something that can be corrected. Otherwise, you’ll probably need to revise the material or design until it works properly.

3. Maybe the material is not rated for the temperatures observed

Make sure that the material is not burning or oxidizing away. This is an all too common issue. The internal temperatures can very easily exceed what was intended in the design phase once you start testing.

4. There might be too much pressure for the material chosen

Is the internal pressure too high and forcing a leak? If this turns out to be the issue, explore the reasons for the pressure and what can be done about it. Gasket design may require reinforcement from the flange ring to accommodate the pressure.

5. Does it look like there are expansion/contraction issues

Check to see if the thermal expansion may be tearing the gasket apart. If so, can you add a coating to provide lubricity? Otherwise, a more robust material might be the answer. (Metal Tech would offer our AR400, or something similar, in this situation.)

6. None of the above

If the issue is still a mystery, look at the history of similar applications to see if there is anything obvious that stands out as a factor. Historical comparisons can sometimes be your best troubleshooting method.

Happy Troubleshooting!

As you can see, your exhaust leak could be stemming from various issues. If you weren’t aware of all of the potential causes, hopefully this list will help you focus your investigation. Although some of the causes aren’t directly attributable to your gasket material, a lot of times, a different gasket material can fix the problem (it’s a lot less expensive than a redesign). Once you have narrowed down your issue, talk to your trusted gasket material supplier. They may be able to help you with some of the troubleshooting, or possibly suggest a material that will better meet your needs.

What is the most common culprit in your exhaust leak issues?Armor Comparison