Re-torque?!? We don’t need to re-torque! Or do we??

Do you understand when and why a re-torque would be needed to maintain an optimal seal in your joint? Is a re-torque ever not necessary? All of these burning questions and more are addressed in this week’s post.

Re-torque or Not to Re-torque?

1. Typically, when and why do a majority of re-torques need to happen?

The best scenario is to re-torque all gaskets after they have seen their first heat cycle. This will provide sufficient loading after the initial relaxation of the part due to heat exposure. Gaskets that NEED to be re-torqued are typically softer construction, with low recovery values and can benefit by being reloaded or re-torqued.

2. Under what conditions would a re-torque not be needed?

Stiff gasket materials with good recovery and low creep-relaxation properties such as metal gaskets or high density graphite gaskets would be an example of such items.

3. Are any re-torques ever required beyond the initial one?

Typically, no. Further re-torquing will result in crushing of the material beyond it’s designed loading. Most OEM gaskets are designed to be used without re-torquing, as this is not an option on a new engine. Aftermarket parts, however, can often be re-torqued, depending on the application, allowing a more cost-effective material selection to perform adequately.

4. Can multiple re-torques be a sign of a design flaw or gasket issue?

It is normally not necessary to re-torque more than once. Ongoing leaks or gasket failure indicate that a better material should be selected in that joint.

5. What are some of the conditions you might observe when it is time for a re-torque?

Bolts may be loose or have low retained torque. Also, the gasket may exhibit slight leakage or failure to seal.

Now You Know

We hope this helped clarify any misunderstanding that might be out there regarding re-torquing and its standard practices. It really is very straightforward when it does and does not need to occur, and a lot of it really is material-dependent. If you have any questions or concerns about a specific material, talk to your trusted gasket material supplier.

Until next time!Hi-Tex Comparison

The Why’s and How’s of Coating Your Gaskets

There are many reasons why one might coat a gasket. The motive may vary, but one thing is certain – a quality coating is necessary. Today, we’re going to look at some of the reasons why you may want to coat your gaskets as well as the types of coatings you should be seeking out and how they may be applied.

Continue reading for some of the why’s and how’s of coating gaskets.

Why Coat?

Whether your decision to coat your gaskets is driven by performance or cosmetic needs, there is a coating to meet your requirements. Here are a few reasons why you may choose to coat your gaskets.

1. You want to stand out.

Sometimes it is strictly cosmetic. You want your gaskets to be red, so you coat them, and everyone knows red gaskets belong to you. Users receive the benefits of the coating, but your main goal is branding.

2. You need to provide some ‘slip’ in your joint.

Do you have a lot of movement between your flanges? Movement can be caused by expansion and contraction of the metals and sometimes those happen at different rates. Having an anti-stick coating on your gaskets protects them from damage and allows them to move with the flanges.

3. You intend to try to reuse your gaskets.

Although it usually isn’t recommended by those in the gasket industry, there are some users that try and successfully reuse gaskets. Coated gaskets tend to not see as much wear and tear during use, and typically can be removed without much damage.

4. You need an easier teardown.

Sometimes speed and efficiency is a necessity during teardown, or you have better things to do than spend hours bent over a flange chipping away at a gasket. Regardless, coatings provide anti-stick properties that allow for a clean release from the flanges.

5. Seal improvement

Coatings can also provide “micro-sealability”. In the case of fiber-based products, coatings can saturate the fibers and block potential leak paths through the body of the gasket.

How to Coat?

The first thing to understand is the difference between your choices in coatings. Some coatings contain a release agent for anti-stick properties, while others contain polymer compounds for enhanced sealing.

To apply the coatings, it ultimately depends on the form in which the coating is produced. However, typical means of application are spraying, rolling, dipping or brushing. Depending on your preferences, it can be added to materials prior to being cut or applied to finished parts.  Coating a cut part is preferred, as the coating will then be applied to the inner and outer sealing edges for full encapsulation.

Know Your Need, Make Your Selection

Once you have decided that a coating is necessary for your gaskets, you just need to find the one that best fits your need. Most gasket material suppliers are familiar with coatings, so if you have any questions, talk to one you trust to get the answers you are looking for.

Should YOU be coating YOUR gaskets?TechCoat Product Comparison

6 Ways to Ensure You Have a Tight Seal in Your Gasketed Joint

The lack of a tight seal in a gasketed joint is a ticking time bomb. The timing of the issue presenting itself may vary, but unfortunately, you will have issues. The good news (for those of you that love troubleshooting) is that there are a variety of things that can contribute to the problem. In a perfect world, all of these things would be addressed during the design phase. Hopefully we can help some of you start to recognize these things sooner rather than later to get you out of the troubleshooting group!

We put together a short list of things that you should consider when it comes time to design or troubleshoot your gasketed joint.

Ways to Ensure a Tight Seal

1. Is the proper load applied?

Bolts not tightened to the proper torque values spell trouble for your application. If the load values defined in the development stages are not adhered to, you will most likely find a leaking gasket (and possibly further damage if it goes on for too long). What if you don’t know what the load should be? Start with the specified gasket material. You may be able to reverse engineer the values based on the recommended loads that the gasket material is designed for (you may need to talk with the materials supplier). You might also gather input from service instructions for similar applications. It will take some trial and error, but you can probably figure it out.

2. Can the gasket withstand the conditions it is under?

Sometimes conditions in the application are underestimated, and sometimes the robustness of a certain gasket material is overestimated. Whichever way it happens to go, there will most likely be problems. Is your gasket material designed to resist the effects of the fluid, pressure, and temperature of the joint? If it isn’t, you can count on having trouble maintaining a tight seal. However, this is generally an easy fix if you do a little research into materials that can withstand the specific conditions in your application and choose properly.

3. Is the bolt design sufficient?

This is probably the most expensive problem on this list. A redesign due to an incorrect bolt design can cost a lot of money, especially if you are too far down the design path. If your answer to this question is “no”, and you do have an insufficient bolt design, we can offer some advice on where to go from here. If there is any hopeful news in this scenario, it is that there are materials out there that are more forgiving than others that can help mask questionable design choices. Talk to your trusted gasket material supplier about some of the composite materials on the market. Three layer composites (or metal reinforced materials) can be manufactured to a specific thickness and they conform very well to flange surfaces – both of which can help compensate for bolt design issues. It isn’t always a magic bullet, but it’ll do the job in a lot of situations where nothing else will work.

4. Are the flanges appropriate for the gasket technology chosen?

Flange surface finish plays a huge role in the ability for certain gasket materials to adequately hold a tight seal. Gaskets made of stainless steel (MLS/SLS) require mirror-smooth surfaces, while metal reinforced graphite and certain fiber gaskets are more forgiving. If the flanges are not machined properly, or they wear over time, you will start to have sealing issues with MLS/SLS.

5. Are the leakage requirements met?

It is a common misconception that a gasket is expected to never leak. Leakage requirements are set during the design phase (you’ll commonly see mL/minute or mL/hour) and the load on the joint has a direct effect on whether or not these numbers are achieved. If you are exceeding your leakage requirements, that is a clear indication that your seal is not as tight as it needs to be.

6. Is a re-torque necessary?

What if you’re feeling pretty confident in everything above, and you’re still having issues with maintaining a tight seal? Maybe the solution is something as simple as a re-torque. If you have gaskets installed that are going through their first heat cycles, bolts loosen and a re-torque is often necessary. Without it, the tight seal you thought you had prior to running your application is long gone.

Maintaining the Seal

As you can see, there are definitely some things to consider if you are having trouble maintaining a tight seal. Some are always quick to blame the gasket, but a gasket is only as good as the conditions that it is designed for and the type of conditions it is placed under. It is important to have a full understanding of all of the things that can lead to the demise of a tight seal.

What is the most common issue you find with your seals remaining tight?Armor product comparison

3 Reasons Why It May Matter Which Side of the Gasket Is Up

If a tree falls in the forest and no one is there to hear it, does it make a sound? Which came first, the chicken or the egg? Which side of a gasket needs to face up? Ok, maybe a gasket having sides isn’t one of the great hypothetical questions of our time, but have you ever really thought about it? Believe it or not, there are instances where it matters. Whether you have spent any time debating this with others or not, here are a few things that you need to know.

This Side Up

Here’s how to know if your gasket has a “this side up”.

1. Fitment and Alignment

Some gaskets are nearly identical on both sides, but often there is a slight alignment issue either for the bolt holes or ports. Be sure to have the proper side so it assembles properly.

2. Surface

Some gaskets are directional, meaning they only go one way. This can be for heat purposes. For example, our single-sided Armor material is designed to go with the hot side against the head surface and the soft side against the irregular surface of the manifold/header.

3. Coatings

Sometimes gaskets are coated to aid in their performance. It is possible to apply an anti-stick coating to only one side to aid in removal. Similarly, some gaskets will have a PSA (pressure-sensitive-adhesive) applied for assembly. This also must be applied to the proper side.

What Happens If I’m Wrong?

Well, the good news is that not all gasket designs require a specific side to be up. If you use a gasket where it does matter, and you get it wrong, you’ll definitely know it. Some of the issues you may see include leaking due to port alignment, crush due to bolting issues, sticking if the coating is on the wrong side, etc.

If you flip the gasket over and still see issues, you may have a problem with the joint or the gasket material being used. Talk with your trusted gasket material supplier. They may be able to provide some insight into the problems that you are encountering to help with your troubleshooting.

Until next time!Armor product comparison

Need To Design A Gasket Material? Here Are 6 Questions That You’ll Likely Be Asked.

How many times have you been working with a gasket (by itself or in an application) and wondered if you could change something about it to make it work a little better? Sometimes the options in the market don’t quite meet all of your needs, and you have an idea that just might work! Now, if there was only a way to bring it to fruition…

Did you know that there are some gasket material manufacturers that design and engineer new materials, and that you can reach out to one to vet out this idea? Depending on your level of experience with the various material constructions, maybe there is already something out there to fit your need. If not, material manufacturers (especially those that work with composites) have a lot of options.

If you proceed down the path of working with a materials manufacturer to design a material, or requesting that a materials manufacturer figure out if they can design something to meet your needs, you’ll most likely need to be ready with answers to these six questions.

What To Be Prepared For

1. What type(s) of applications are we looking at, and what does it need to seal?

2. What are the operating conditions and temperatures?

3. What do you like/not like about what is currently being used/proposed?

4. What are the flange conditions? Is there sufficient flange load available?

5. What is the design life of the joint? How long does the gasket need to last?

6. What is the target price range? Are we basing on price or performance?

The more detailed answers you can give, the easier it will be to take a look at your needs and figure out if something can be designed to meet them (or like we mentioned earlier, maybe something exists that you weren’t familiar with). There are a lot of options out there, especially when working with composites, and raw material improvements over the last few years continue to advance the capabilities and performance of composite gaskets.

Pick Up The Phone

Gasket material manufacturers, especially ones that offer engineering and design support, are always ready for the next challenge. Continuous improvement of gasket materials and their abilities is a goal that everyone should be striving to reach, because we all will benefit. Don’t be satisfied with a material that works “ok” – if there’s room to improve something or if there a need to be met, pick up the phone and start investigating whether there might be a solution out there.

What innovations would you like to see?Request a Call