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

3 Things You Should Look for When Selecting a Gasket to go from Cylinder Head to Exhaust Manifold

Every seal point is unique in its gasketing needs. Due to this, special attention should be paid to the type of gasket material that is selected for use in the various seal points. What you are sealing, as well as temperature, pressure, flange conditions, and available load are all factors that matter.

Exhaust manifold gaskets are no exception. Having an understanding of the conditions that this gasket is exposed to makes it much easier to decide on a gasket material. In the absence of you knowing exhaust manifolds inside and out, we are happy to get you pointed in the right direction.

Things to Look For

Here is a list of some of the more ideal characteristics of a gasket material used in the exhaust manifold.

1. Heat tolerance

The gasket material should be able to withstand the temperature of the application without oxidizing, burning, or otherwise disintegrating. MTI offers the Hi-Tex line of products for high temperature applications.

2. Conformance

The gasket should compress or conform to flange conditions and irregularities to make a good seal. Is the joint designed for a precision steel gasket, or can a cost savings be found by utilizing a proven, composite style design? MTI’s Hi-Tex line of laminates also performs very well in the exhaust manifold.

3. Flange conditions

Is there thermal motion and scrubbing present? Sometimes gaskets must be very robust to resist or tolerate thermal motion and still maintain a seal. MTI’s Armor products address this issue with metal-clad construction.

Deciding on a Material

Once you understand what is necessary to have in an exhaust manifold gasket, it becomes pretty easy to narrow down your material choices. If you still aren’t sure about the material that will best meet your needs, talk to your trusted gasket material supplier. They should be able to recommend a material that is a known performer in this seal point.

What other characteristics do you feel are important in this seal point?Armor product comparison

Year in Review: Top Blogs From Our Two Years of Blogging

Sealed-In is now celebrating its two year blog-iversary! Our viewership continues to grow, and we hope that you have enjoyed the content we have produced (and learned something too!).

As is now our annual tradition, we decided to do a recap of our most popular blogs over the last two years. See below for our top 5 list of Sealed-In blogs.

The Top 5

Is There A Difference Between Gaskets & Seals?

3 Things You Need to Consider When Deciding on EGR Gasket Material

The Great Gasket Debate: To Reuse or Not To Reuse

What is Creep Relaxation, and Why Do I Care?

Why Would I Use Composite Gaskets When I Can Use MLS?

Thank You!

As always, thank you for your readership. We hope that we are becoming one of the first places that you go for information related to gaskets and gasket materials. If there is ever a topic that you’d like us to cover, please let us know – just drop us a comment in one of the blogs.

On to year 3!Request a Call

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

3 Reasons Why You May Want to Utilize an Insulating Gasket

Sometimes a gasket needs to be more than just a gasket. There are times you may find that you are in need of an insulating gasket. There are also times that you could use an insulating gasket and don’t even realize it. If you’re not quite sure what you need, continue reading to learn about a few instances when an insulating gasket may be a benefit to your application.

Before we jump into a few examples, we thought we’d start with a short explanation on insulating gaskets in general. First, it isn’t a new gasket technology. Gaskets with insulative properties have been on the market for years. However, due to the increased heat in applications, the benefits of these materials are now in demand as engineers are constantly working to manage the heat.

So what are these materials? Metal reinforced composite laminates are your best choice when it comes to high temperature gaskets that also require insulative properties. Insulative materials by themselves can be fragile, the metal core gives them strength.

Reasons to Utilize an Insulating Gasket

1. There isn’t room for a heat shield.

Engines are getting both hotter and smaller, which is not a good combination if there are sensitive components that need protection. Designing a heat shield small enough to fit into some of these areas can be a difficult task. If there is a way to utilize the insulating properties of your gasket to reduce the heat flow, you may have solved your space issue.

2. Save money and simplify your design.

We don’t know any engineers that want to add cost and complexity to any design, so if there is a way to minimize both of these with simply a gasket, why wouldn’t you at least check it out?

3. You suspect heat soak is present.

All systems may be humming along while the application is running. However, what happens when it is turned off? Heat soak is a common issue when there are no cooling systems protecting sensitive components. An insulative gasket does its job whether or not the application is running. An example of this might be EGR valves, where actuators are better if they don’t get as hot as the valve itself. Heat soak can be an enemy here.

Selecting a Material

As with any application, you need to ensure that any gasket material chosen is suitable for the conditions that it will see. The best insulative materials are going to be metal reinforced composites that contain vermiculite, mica or fiber materials. Finding which one seals and insulates best in your application is something that will need to be tested. As you explore this idea, talk to your trusted gasket material supplier to narrow down your choices.

Have you used an insulating gasket before?Hi-Tex Product Comparison