It would be nice if there was a one-size-fits-all, high-temperature insulation solution for refineries, petrochemical facilities and power plants. Unfortunately, given the dramatic variations in application requirements, there simply isn’t a single insulation on the market today that will provide optimal performance in all conditions.

As designers start to look at the varying requirements of every application, it becomes clear that insulation requirements can be broken down into two general categories:

  1. Application-Dependent Requirements – These are requirements that are based on job-site conditions. They include factors like location, temperature ranges, configuration, etc.
  2. Material-Dependent Requirements – These are based off the features that are unique to the insulation that help determine the best material choice for the application.

In this blog, we will address the interplay of both application-dependent and material-dependent requirements that engineers and owners typically come across for any given application. While this is not a comprehensive list, these are some of the most common details that need to be considered when choosing an insulation material.

  • Operating Temperature Requirements
  • Safety
    • Safe-to-touch standards and personnel protection
  • Process requirements
    • Below grade
    • Cyclic/constant operating temps
    • Stainless steel pipes/tanks
  • Corrosion protection
  • Design life
    • Life-cycle cost (installation, operation, maintenance)
    • Reusable after service
  • Vibration
    • Proximity to motors/turbines
    • High-pressure steam pipes
  • Abuse conditions
    • Prone to foot traffic
    • High-maintenance area
  • Freeze protection

As the list of variables only gets longer from here, it’s not unreasonable to see why a single insulation cannot address every application. While all of the application conditions are important and should be considered carefully, they do not all hold the same level of importance for every application. That is to say, the most important variable for one application (like compressive strength) may not necessarily be the most important variable in another application (such as a corrosion inhibitor).

Since no insulation can cover all these variables, it’s essential for owners and engineers to prioritize which conditions and characteristics hold the most importance for their specific application. The table below shows a comparison of several common insulation materials and how they rank with respect to common design parameters.

Material CharacteristicCalcium Silicate ASTM C533Expanded Perlite ASTM C610Mineral Wool ASTM C547Microporous ASTM C1676
Maximum temperature1200120012001200
Thermal resistanceGoodGoodBetterBest
Dimensional stabilityBestBetterBetterGood
Compressive strengthBestBetterGoodGood
Corrosion resistanceBestBestGoodGood
Moisture resistanceGoodBestGoodBest
Material costBetterBetterBestGood
Life-cycle costBestBetterGoodBetter
Ease of InstallationBetterBetterBestGood
Physical abuse resistanceBestBetterGoodGood
Space requirementsGoodGoodGoodBest

*Qualitative rankings based on extensive experience on a variety of job sites.

It’s evident from this chart that no single, high-temperature insulation offers the best performance across the board. The designer must evaluate each specific application and determine which conditions take priority. From there, the designer should consider each insulation material to determine which one offers the best mix of physical characteristics and performance metrics to match the application conditions and requirements.

Reprinted with the permission of Industrial Insulation News and Trends. Copyright 2015 Johns Manville Industrial Insulation Group.