Weighing Your Options for Insulating Spheres

By Technical Services

February 26, 2018

The weight of insulation is becoming increasingly critical for today’s congested industrial sites. For some sites, turnaround and maintenance schedules can be negatively impacted by space and weight limitations—just think about the use of cranes where space is restricted as an example. In this post, we focus on the weight of thermal insulation, including when it becomes an important consideration for refinery and chemical processing engineers.

Spherical tanks are an efficient option for storage of pressurized liquids and gasses; their iconic shape is instantly recognizable in refining and chemical processing facilities throughout the world. Detecting corrosion under insulation on a sphere might be enough to ruin your day, but it is not an unexpected outcome, especially on older tanks with conventional cold insulation.

However, upon closer examination, you’ll notice that these spheres rest on an array of steel legs—steel legs commonly encased in concrete for passive fire protection. Over the years, water can intrude between the steel legs and the concrete protection, leading to what is known in the industry as “corrosion under fireproofing” or CUF.

As a result of water intrusion and CUF,  the integrity of the sphere’s legs, especially on older spheres, is not always certain. And that’s a serious concern for engineers and plant personnel. Even more concerning is the weight that sits atop those legs.

One way to address the load bearing down on a sphere’s legs is to consider the lightest possible insulation design, one that is light to begin with and does not absorb water over time. (Water absorption will add significant weight to the structure, adding to the strain bearing down on the legs.)

The Cryogel Advantage

Cryogel® Z flexible aerogel blankets are engineered to deliver maximum thermal protection with minimal thickness and, of course, weight.

Take for example the difference in weight of an 82ft (25m) sphere insulated with Cryogel aerogel blanket versus a cellular glass option. At the same level of performance, the Cryogel option would weigh a whopping 8 tons (~8000 kg) less. That’s the equivalent of four pickup trucks parked on top of your sphere.

Of the many advantages offered by Cryogel, including durability, flexibility and time-saving construction, reduced weight gives peace of mind to refinery and chemical processing engineers who are concerned with the integrity of supports in older spherical tanks.

Without added bulk or weight due to the thin and ultra lightweight nature of Cryogel insulation, you can insulate a sphere, defend against CUI, and reduce the static load on the legs. After all, spheres should be no parking zones for unnecessary weight. Want to learn more? Contact us.