CUI Defense Resources

Pyrogel is a super-efficient insulation material based on aerogel technology. Pyrogel offers industry leading thermal insulating properties, and it has been engineered to offer superior protection in CUI service conditions.

1. Simply put, Pyrogel keeps your piping and equipment dry.
2. Corrosion only occurs in a wet environment. The implication of wetness on insulation selection is well summarized in section 2.1.2.1 of NACE Standard SP0198 Control of Corrosion Under Thermal Insulation and Fireproofing Materials:

1. “Because CUI is a product of wet metal exposure duration, the insulation system that holds the least amount of water and dries most quickly should result in the least amount of corrosion damage to equipment.”

Pyrogel has been engineered to keep your process dry and has multiple ways it does this.

1. Wet insulation often begins with mechanical damage to the jacketing. Pyrogel’s extremely thin designs (typically only 5-20 mm within the CUI temperature zone) and resistance to crushing help minimize the dents, buckling, and subsequent water ingress caused by footfalls or tool strikes on the jacketing.
2. In the event that water does get past the jacketing, Pyrogel is strongly water repellent (hydrophobic) with very low moisture uptake.
3. Often installed with more than one layer and with staggered seams, Pyrogel provides multiple layers of water repellent/water-shedding defense
4. It’s vapor permeable, which promotes rapid dry out

 

 

 

 

 

1. Pyrogel is durably water repellent because its hydrophobe is integral to the chemical backbone of the aerogel matrix. Most other hydrophobic materials achieve their water repellency via a less durable “surface coating” approach.
2. Because the hydrophobe is integral to the Pyrogel, cut edges of Pyrogel perform equally to manufactured surfaces.

    

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1. All hydrophobic treatments can be impacted by long-term exposure to temperatures above 250°C (480°F), and Pyrogel is no exception.
2. However, most forms of CUI are only active below 150°C (300°F) and, within that range, the thermal stability of Pyrogel’s hydrophobicity will be far longer than its expected service life.
3. Finally, because the temperature within the material decreases with distance from the pipe or equipment, it is only the innermost surface of the Pyrogel that is ever exposed to the full process temperature. Outside of that, a durably hydrophobic shell remains intact, even at process temperatures approaching 650°C (1200°F).

Pyrogel is durably hydrophobic, which means it will resist liquid water penetration, but no system is perfectly water-tight. In the event that water slips behind the material, Pyrogel’s breathability keeps it from becoming trapped against the surface. As long as the pipe or equipment is operating above the local dew-point, the vapor pressure gradient will eventually dry the system back out. Internal and external testing has shown that Pyrogel dries out faster than any other insulation material. 

 

Properly installed Pyrogel with staggered longitudinal and circumferential overlaps create a “tortuous path” of water repellent layers that is difficult for liquid water to breach.

 

Pyrogel performs best in CUI defense when used as part of an appropriate system. Design guidance can be found in CUI relevant standards such as SP0198 or API 583.  In general, these systems should include:

1. A high quality protective coating system properly installed on a properly prepared surface
2. Pyrogel insulation
3. A properly installed mechanical jacketing material/system

A well-designed and executed risk based inspection (RBI) program is also a component of effective CUI prevention, and damaged jacketing should trigger inspection and correction as soon as practically possible.

Pyrogel is extremely hydrophobic throughout the temperature zone where CUI can exist.  It strongly repels water from the environment or adjacent processes.  Pyrogel is engineered to be homogenously hydrophobic, it does not rely on surface coatings which are bypassed when cut, liquid water is repelled from every surface, this makes it almost impossible for water to breach Pyrogel’s defenses. 

Pyrogel has a second line of defense for those rare real world occasions where water does get between it and the underlying assets – Pyrogel is breathable, water can evaporate quickly, minimizing the time in contact with water and minimizing the potential for CUI to occur.

In typical service conditions, Pyrogel remains flexible.

 

Because Pyrogel is very resistant to mechanical damage and abuse, it can usually be reused after inspection of the asset. Due to differences in geometry of each piece, they will need to be re-installed in the same order, location, and fashion as originally installed.  If any damaged layers of insulation are discovered, good practice dictates replacement.

1. Pyrogel has been tested according to, and met the requirements of, a range of tests concerning “leaching” corrosive ions into the insulation system including C1617, C871, C692, and C795.
2. Pyrogel is compatible with the Karn’s Curve for Austenitic Stainless Steel and is suitable for use in systems including stainless steel materials.

Pyrogel’s formulation includes a corrosion inhibitor that will raise the pH above neutral.

When working with any material, it is important to review and follow the requirements of our SDS when working with Pyrogel.  As is common with many insulation materials, working with and cutting Pyrogel will generate nuisance dust.  Safety glasses, long sleeve shirts, pants, work gloves, and dust masks are advisable for worker comfort.

 

Aspen’s team of Technical Sales and Technical Service members can assist you during project design and installation. Please click here to contact us.

 

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