Under the perfect conditions, most sealants will perform proficiently to keep parts in place or to restrict air and liquids from escaping/entering. Unfortunately, perfect conditions are rare in many industrial situations and when temperatures start climbing, pressure increases as well.

In order to avoid dangerous and costly situations, it is crucial to use the correct sealant in high temperature and pressure applications.

What makes selecting the correct sealant such an exact science is that temperature isn’t the only determining factor. PSI, chemicals, and function are all important details that must be accounted for when selecting the appropriate sealant.


In high-temperature applications, it is imperative to select a sealant for both the operating temperature as well as the maximum temperature it can reach. For example, a home furnace usually runs at roughly 60-70° but is probably capable of reaching 90°+.

Sealant degrades in high-temperature situations so it is important to select a product that can take the heat. Our 3300 and 8875-Thin are excellent products to be used for higher temperature applications.


One thing that sealants must stand up to is loosening caused by vibration in high-pressure situations. High-temperature applications are often accompanied with intense PSI levels so a more durable sealant is recommended. For higher PSI requirements, a lower viscosity sealant (400-600 cPs) is used to retain flexibility, which is also important when materials expand/contract during thermal cycling.

If the joint is under low stress, a thicker product can be used.  Sheer strength and breakaway torque are two important ratings when finding a sealant that will perform under pressure. Our 770-L sealant performs the best under high PSI applications.


Along with temperature and PSI, chemical exposure is another key factor in determining which product to use. Our 3100 sealant is designed to have excellent chemical resistance to ammonia, steam, oils, hydrocarbons, solvents, propane, etc.

For Performance 

Our 3300 and 8875-Thin are both great products that can be used to increase the efficiency of furnaces by retaining heat as well as sealing combustion and dirt. These are typically low PSI situations but with high temperatures.

We realize that every application is different and may fall into one or more of these four categories. Most situations will involve a slight mix of high temperatures, chemical exposure, pressure, and performance while other elements such as surface texture and material are also deciding factors.  It is important to consider all of the working variables before choosing which high-temperature sealant may be right for your application.  AccuTrex is happy to give you hands-on advice for selecting the perfect product and we are standing by for assistance.