When deciding what characteristics you need in your gasket, most people start with the basics – what type of material is necessary and what thickness is needed. Once you start to dial in on your selection, then you start to look at the various material properties that are specified (compressibility, recovery, creep, ignition loss, etc). All of this is done (most likely) with cost considerations in the back of your mind.
Another consideration that sometimes needs to happen is whether or not the gasket needs an anti-stick coating. Our cost-conscious readers might cringe a little at the thought of this because adding an anti-stick coating does add some cost to your gasket, but can you afford not to do this?
Do I Need An Anti-Stick Coating?
Anti-stick coatings can improve your gasket’s functionality and performance. Here are a few things to consider when deciding if an anti-stick coating is needed.
1. What is the design life of the joint?
Some joints are meant to be permanent, with engineers preferring a good bond to both flanges. In this case, an anti-stick coating would not be used, but perhaps a sealant coating.
2. Is it expected to be taken apart for maintenance?
In some cases, a clean release from flanges is preferred for maintenance or other reasons. In this case, the anti-stick coating will help the gasket release from the flanges upon teardown.
3. What are the flange materials? Are they dissimilar metals?
Flanges with dissimilar metals expand and contract at different rates. An anti-stick coating on the gasket provides a higher degree of lubricity and “slip” to allow the gasket to move with the joint instead of tearing apart.
4. Given temperature exposure, is there motion expected in the joint (expansion/contraction)?
Similar to #3 above, even flanges of the same metal can expand at different rates due to their structure and create a tearing effect on gasket materials. Anti-stick coating can address this issue and prevent damage to the gasket.
Ok, So I Need It
As you can see, it is very important to consider whether or not the gaskets in your application need an anti-stick coating. Most often, if a value-added step like this is needed, it is going to benefit the application in the long run. As we’ve said before, you never want the gasket to be the reason an application fails. Do your research and make sure the gasket going into your application is going to be able to get the job done.
Now, let’s get coating!
If you are interested in learning more about anti-stick coatings, and what Metal Tech offers in this area, check out our TechCoat product comparison!