4 Questions to Ask When You Need to Seal Gases

Today we’re going to talk about sealing gases. Don’t worry if you aren’t familiar with how to select a proper gasket material to get the job done. Yes, there are things you need to know. No, it’s not impossible to figure out. However, you need to know what you’re doing, or work with someone that does in order to get it right. We’ve listed some of the important things to pay attention to when sealing gases to get you going down the right path.

 

 What You Need To Know

1. What type of gas are you sealing? (i.e. exhaust gases? diesel?) Different gases present different challenges due to the variation in properties. Depending on what you are trying to seal, you may need to select alternate materials.

2. Is it a corrosive environment? (i.e. urea present?) If so, it may require stainless steel reinforcement to withstand the corrosivity. Other materials probably won’t survive.

3. What temperature will the joint see? Is there expansion/contraction present? These answers will determine the materials where you should focus your effort. When dealing with gases, you will routinely see temperatures higher than 1000°F, making some types of materials inadequate. If you are seeing expansion/contraction, you’ll need to select a material that can withstand the changing conditions and still maintain the seal.

4. What type of design life are you designing for? Is this gasket being designed based on price or performance? As with every design, knowing what the ultimate goal is will help your gasket material supplier suggest a material for you. If price is the driving factor and performance is secondary, you will most likely end up using a different material than if performance was the most important and the price was no object.

 

Make Your Selection

As you can see, narrowing down your gasket material selection in order to seal gases can be pretty straightforward if you know what questions to ask. There are a lot of materials out there that are worth your time to investigate. Talk to your trusted gasket material supplier to discuss your options and make the best choice for your application.

What are the biggest problems you face when trying to seal gases?

4 Questions to Ask When You Need to Seal Gases

Is There A Fluid Leak In Your Joint? Here’s What You Need To Know.

If you work with applications that require a gasket, four words you never want to hear are: “We’ve got a leak”. (We know there are others, but we’ll just focus on gaskets since that’s what we can help with.) There are a lot of factors that can contribute to a leak, and getting to the root cause can sometimes be a difficult task.

Today, we’re going to take a deep dive into some of the potential causes of your fluid leak. As you’ll see, you can’t always just blame your gasket. Below are a few reasons why your joint may be leaking fluid, and what you can do about it.

 

Why Am I Leaking Fluids?

1. Is your gasket material compatible with the fluid you’re sealing? – Not all materials are created equal when it comes to sealing fluids. Some gasket materials are designed to “swell”, creating a better seal when coming in contact with fluids and oils. However, some fluids can actually disintegrate improperly chosen gasket materials. Be sure you understand the interaction between what you are sealing and the gasket material.

2. You might have a design problem. – You’ll want to do your homework with this one. Design problems can be a big issue. Is your joint loaded sufficiently, and is the load distributed properly and evenly? Do you see any flange distortion? What is the finish and the flatness of the flange? Unless you can find a gasket material that can compensate for the design issues, you’ll be back to square one. If this is the case, be sure to investigate all of your material options before entering into a redesign. There are materials out there that can compensate for a lot of design issues, so be sure to talk to a gasket material expert to help you find the right solution.

3. What is your internal pressure? – If there is too much pressure for the material chosen, a change may need to be made. High pressure can force leaks. A gasket design may require reinforcement with a metal core or from a flange ring to contain the pressure.

4. Is your material rated for the temperatures in your application? – If your material is burning or oxidizing away, take a look at your temperatures. A lot of times, internal temperatures can very easily exceed what was intended in the design phase once you start testing. You may need to get your hands on a higher temp-rated material.

5. You might have expansion/contraction issues. – Does it look like thermal expansion is tearing your gasket apart and causing a leak? If so, can you add a coating to provide lubricity? This would allow the surface to “slip”, thus accommodating this effect. If not, you may need to look at more robust materials.

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 a helpful troubleshooting method.

 

Stopping the Leak

Dealing with unexpected results can be incredibly frustrating, and with a fluid leak, it is very easy to just assume the gasket is the issue and start testing various materials just to find a solution. Taking the time to really understand the underlying causes of your problem will help you make a much more educated decision. Once you start to understand why your joint is leaking, talk to your trusted gasket material supplier. They should be able to suggest a material that will better fit the requirements of your application.

Until next time!

surbond-comparison

Is There A Difference Between Gaskets & Seals?

Today we’re going to talk about gaskets and seals. These terms are generally used interchangeably. After all, gaskets seal a joint…so they’re the same, aren’t they?

We want to get your thoughts on the matter. We invite you to take a break from reading and answer the poll below. Don’t worry the results are anonymous…and try to avoid the temptation to scan the rest of the article before answering!

Is there a difference between gaskets and seals?

Thanks for taking the time to vote in our poll. Read on for the facts about gaskets and seals.

 

Gaskets vs. Seals

The terms “gaskets” and “seals” are often used interchangeably. The fundamental difference is that a gasket is a physical piece that goes between two flanges to create a seal at a joining point between two components. A gasket is a seal. “Seals” is a category that encompasses many types of seals. In addition to gaskets, there are rotary seals, O-ring seals, liquid sealants, mechanical seals, shaft seals, valve stem seals, and packings, just to name a few.

Generally, seals require more machining for the sealing surfaces, and a controlled size or quantity of seal material to make it up. They are typically “engineered” as a solution and designed up front.

“Seals” are also terms noted for non-gasket applications, such as rotary shaft seals. These are a dynamic joint and not something that a flat flange gasket is able to seal.

Gaskets generally function with two flat flanges and the gasket material and construction can sometimes be chosen later in the design stages. Various material constructions are available and must be selected to correlate with the available flanges and parameters.

 

Now You Know

This has been a very general explanation of this topic, but hopefully it has provided some insight into a basic definition of sealing mechanisms. Back to the trivia question…we admit, it was sort of a trick question. A gasket is a seal, but a seal isn’t necessarily a gasket.

Now it is time to stump your friends. Just make sure they at least know what a gasket is before you pose the question!

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Uneven Temperature Exposure – Is There A Solution?

We have recently been looking at applications that have uneven temperature exposure around the perimeter of gaskets. In some cases, one side sees more heat than the other. From the material manufacturing side, there are a number of things we can do.

First of all, it is important to understand why you are seeing uneven temperature exposure. Unfortunately, this happens most of the time during testing (or even field use) as opposed to the design phase. Due to this, you need to sometimes design a material after the fact.

Whether your application was designed that way, or if it is a function of the application running under normal (or sometimes abnormal) operating conditions, your trusted gasket material supplier can help you find a material that will meet your requirements.

 

Drilling Down

Once you understand why you are seeing the uneven temperature exposure, it is time to find a material that can handle it. When you are dealing with composites, the success or failure of your material is going to be in the facings. Here are some conditions that you may be working with:

1. Insulative Issues – In these situations, we can use insulative facings to design the gasket to resist thermal conductivity as much as possible. Not only do you want to keep the heat out, you may be designing to keep the heat in. When a heat shield isn’t practical, you can sometimes insulate with your gasket. (Link to heat shield article)

2. Peak Temperatures – We can select facings to deal with the peak temperatures in a localized area by making the entire gasket resistant to this effect. We can also work with OEM engineers to identify temperature exposure so the proper facings can be chosen.

3. Heat Soak – Sometimes, the steady state operating conditions are not the extreme. The design conditions must also incorporate “heat soak”. This happens once an engine is shut off. With the cooling system no longer operating, the heat of the engine parts flows into other parts, thus elevating the temperature of parts that were not designed for that type of heat exposure. Gaskets and seals must be designed for this. It is possible to have fluid seals like valve cover gaskets, exposed to higher temps due to this “heat soak” mechanism, thus requiring a higher temp material than originally expected.

One of the perks in working with composites in these situations is the ability to utilize two different facings to survive the conditions on each side of the joint. If you can’t find a single material to meet the requirements, work with two!

 

Challenge Accepted

As a company that engineers and manufactures gasket materials, we are always looking for opportunities to create custom solutions for gasket applications that exist in challenging conditions. Working with composites, we have the ability to manufacture exactly what is necessary to meet the requirements for your application, and we are always looking for feedback from the market on what needs are not being met. With new applications being developed every day, there will continue to be unique challenges that design engineers are trying to find a solution for. If this sounds like you, don’t hesitate to reach out to a trusted gasket material supplier to look for answers.

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