Losing Load in a Gasketed Joint? Here’s What You Can Do About It.

There are many reasons why load can be lost in a gasketed joint. Maintaining the desired load can be a challenge at times for a variety of reasons. Today we’re going to cover some of these reasons.

Before we get into it, we want to make sure all of our readers are on the same page and understand what we mean by ‘losing load’. Load is the amount of force (pressure) placed on flanges by applying torque (tightening the bolts) to create the proper seal with the gasket. When you ‘lose load’, your bolts do not retain the torque values applied to them and the gasket will no longer seal properly.

Losing Load

Here are a couple of reasons why you could be losing load, which may help you troubleshoot any issues.

1. Material has creep/relaxation.

Most compressible materials have some level of this which should be considered in the assembly.

2. Improper material selection

Materials exhibit different characteristics in assembled conditions. Be sure to understand the parameters to select the proper choice.

3. Insufficient load

Volts are not torqued sufficiently.

4. Bolt incorrect

Bolts may be undersized or an improper grade for the load required.

5. Environmental exposure or thermal cycles

They can cause materials and hardware to lose load due to compression/recovery, creep/relaxation, bolt stretch/yield, etc.

Find Something That Works

The inability to achieve a proper seal due to loading issues can be a very frustrating issue to resolve. Using some of the information provided above can be a good starting point for you to resolve any of these issues. If troubleshooting seems to point back to a poor gasket material selection or a design flaw that cannot be fixed, talk to your trusted gasket material supplier. They should be able to offer a few suggestions on materials that may be better suited for your application.

What is the root cause of most of your loading issues?Corseal product comparison

3 Reasons You Know That it is Time to Replace Your Head Gasket

Sometimes bad things can happen to good engines. This can be the case with a head gasket failure. Depending on the design requirements and the suitability of your gasket material for the application, the useful service life will vary. However, any application that is in use long enough may require a replacement of the head gasket.

Head gaskets are one of the more difficult repairs on an engine. They require substantial removal of parts, careful cleaning and preparation of surfaces, and methodical replacement and reassembly of the engine components. Nobody really WANTS to replace a head gasket, but sometimes, it’s just necessary.

How do you know when this is needed? Here are a few warning signs:

It’s time to replace your head gasket when there is…

1. Loss of compression

Failure of the combustion seal results in a loss of compression in the engine and loss of power. This is normally obvious when it occurs and requires a replacement of the head gasket right away.

2. Coolant in the oil (internal loss of fluid)

If the body of the gasket loses load and leaks coolant into the oil ports, bad things happen. The oil will be compromised in its lubricity, resulting in possible damage to the internal engine parts. It may also result in excessive heat and other failures. This requires replacement of the head gasket immediately.

3. Leakage down the block (exterior loss of fluid)

The body can also fail to seal the fluid ports resulting in external leakage of the fluid (either oil or coolant) down the side of the block. This can be a more gradual failure of the head gasket and often not noticed until much later.

Replacing a Head Gasket

If you have arrived at the decision that a head gasket needs to be replaced, you need to be aware of a few things.

1. Know that you may not be able to replace it with a similar gasket material without significant repair cost also put into the flanges.

Why? If the original gasket was a MLS (multi-layer steel) construction, this will require extremely smooth surface finish preparation (which equals repair costs). There are other gasket material technologies out there that will save you from this cost.

2. There are various types of replacement head gaskets available.

Graphite products are an excellent choice and can be made to the required thickness and density to meet your needs.

3. It is a complicated repair and replace operation, but not impossible.

Once completed, the engine will have a new lease on life for many more happy miles.

If you have any questions about what you’re seeing with your gasket material, or are looking for suggestions on the types of gasket materials that will work best when a head gasket is being replaced, talk to your trusted gasket material supplier. They will be able to get you going in the right direction.

Is there anything you would add to the warning signs list?Corseal product comparison

7 Ways to Protect Against Gasket Blowouts

The fall guy…defined by the Urban Dictionary as “a person who is left with the blame for a crime, regardless of whether they were involved or not”. In our world, the fall guy is the lowly gasket. Too many times, gaskets tend to be an afterthought in the design process, BUT the gasket (or the material) is the first to be blamed if there are ever any problems in the application. If you are currently designing (or may ever design) an application that has gasketed joints, or are currently in the middle of troubleshooting (or may ever troubleshoot) because of a leak in a joint, this week’s post is for you!

Over the years, we have just about seen it all. We’ve been a part of varying stages of design projects….at times we’ve almost been a part of the design team, lending our expertise to help ensure success once the gasket is cut, and other times we come in at the tail end to suggest a material that will meet your exact specifications. We’ve also been the firefighters…driving in on our big red truck with hoses spraying (ok, not really…) to offer a gasket material solution when everything else you’ve tried isn’t working. Blame it on the design of the joint, blame it on the design of the gasket, blame it on the material, blame it on the rain….regardless, there are potential problems lurking everywhere and we’re here to help you navigate some of those issues. Everyone’s time (and money) is valuable and we want you to be educated and aware of what can be done to minimize your chances of a gasket blowout.

What You Need To Know

Protecting your product launch and the application from the damage a gasket blowout can cause is your #1 priority in design (or redesign). Nobody wants a gasket to be the reason a project can’t launch as planned. Like we mentioned above, your gasket may be the culprit, but the issue might also be something else entirely. Here are 7 things to consider to help protect your application from gasket blowouts.

  1. Material choice: Designers must use caution to select a material that is suited for the operating conditions, including temperature, pressure, fluid resistance, durability (for handling), durability (in service), aging characteristics, and other factors.
  2. Temperature: Consider the peak exposure, and choose material capable of withstanding that level of exposure.
  3. Pressure: Sealing joints that are holding back high pressure need to have a gasket with reinforcement to provide radial strength. Be sure to choose reinforced material for high pressure joints.
  4. Flange loading: Flanges are critical pieces of the bolted joint. Consideration must be given to: flange flatness, surface finish, stiffness, material (expansion), preparation, and others.
  5. Assembly: Joints must be assembled properly to recommended torque values and sequence. Often with compressible products, a second round of final torque once operating temperature has been achieved is also helpful to maintain load over long term service.
  6. Protection: Some gaskets exposed to extreme conditions can benefit by additional protection which shields the gasket body from destructive conditions. Heat flow, fluid erosion, and other “wear effects” can be protected against by flange rings, embossments, coatings, and other protective measures.
  7. Thickness: Generally speaking, the thinnest gasket you can use is the best choice. Thickness gets increased to compensate for flange conditions or other factors. Thinner gaskets have less chance for blowout than thick ones since the load is concentrated over less volume, providing higher shear strength to prevent blowout.

Go Forth

We love a good gasket blowout picture – send us yours and we just might feature it in an upcoming article.

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The Great Gasket Debate: To Reuse or Not To Reuse

To reuse or not to reuse gasket material…that is the question. Depending on who you ask, you will almost always get differing answers and advice. Those people that are cost conscious will almost always recommend to reuse every gasket you can. (“There’s still more life in it!”) Those that are strictly focused on performance will always tell you to never reuse a gasket. (“Once you break the seal, you will never achieve the same level of performance!”)

As a trusted gasket material supplier, our recommendation is that you never reuse a gasket. (Ok, ok, we know you are probably thinking “of course they would say that…they just want to sell more material” – but hang with us on this one.) As an expert resource that knows gasket material inside and out, we’re going to break down some of the arguments for and against reusing, and what you need to consider when making that decision for your application. And maybe…there is a time or two that it really might be ok to reuse one.

Reusing a Gasket

If you’ve never been told, you’ve likely always wondered if that gasket could be reused. “It still looks ok, I wasn’t having any problems with it…I wonder if I could throw it back on there??” Here are some of the common arguments for reusing a gasket, and some situations where it might work to reuse.

  1. If the gasket hasn’t seen heat exposure yet of an operating unit, it might be ok to reuse.
  2. If the gasket hasn’t seen fluid exposure and swelling of an operating unit, it might be ok to reuse.
  3. “It looks ok” is more of a subjective approach, but might indicate that the gasket is still ok to use as long as the initial thickness is still correct and it has sufficient compressibility left in it to achieve a seal.

Replacing a Gasket

There are many people out there that would never replace a gasket. How does one really know if it is going to work the same way twice? Here are some of the common arguments for never reusing a gasket.

  1. Heat exposure: Exposure to elevated temperatures causes materials to deteriorate. Sometimes this means: dry out, stiffen up, saturate, get brittle, take a set, etc. Once this seal has “seated” in the application, it should not be disturbed. A new gasket is required to go through the initial seating phase and achieve a proper seal.
  2. Fluid saturation: Exposure to fluids sometimes causes materials to swell, impregnate, or saturate. In a seal situation, this often helps to create the seal. Reusing a gasket is not advised as the saturation and absorbancy condition can vary. A gasket should be assembled, then exposed to heat and fluid. A used gasket already having swelling due to the fluids should not be reused.
  3. Compression set: The third reason not to reuse a gasket is related to the first two. Once a gasket has taken a set (due to temperature and fluids), it should not be disturbed or reused. It would not have the same properties available to go through the initial compression provided by the joint and achieve the initial seal.

Our Recommendation

Like we’ve mentioned, our official position is to never reuse a gasket. As a gasket material manufacturer, we run our tests and certify our products when our material is at 100%. We know for a fact that our material can handle the conditions it is specified for IF the gasket (and joint) is designed properly, and installed correctly. What we don’t know is how our material will work after the seal has been disturbed or disassembled. It may work just fine, it may have been damaged in the process – we don’t know, and it would be impossible to test in enough conditions to enable us to come to a strong conclusion that we would have any confidence in.

We take pride in the quality and the performance of our material (as do many others), and we don’t believe the risk of damage to your application is worth the reward of saving a few dollars from reusing a gasket.

Replace to be safe!

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