Corrosion Under Insulation


What is Corrosion Under Insulation? Corrosion Under Insulation is a multi-billion dollar problem
that destroys expensive industrial infrastructure and causes continuous scheduled manufacturing plant and facility
downtime to conduct inspections for failure and unexpected downtime when equipment failure occurs.

It is exactly what it sounds like… corrosion of pipes, tanks, and equipment which occurs under the pipe insulation and, in
many cases, is caused by insulation. The root cause is simple: At the interface between the pipe insulation and the
substrate to which the insulation is applied there is a temperature differential. Regardless of how tight a pipe insulation
material is wrapped around, or applied to, the substrate there is a space where the temperature makes a quick change
from higher to lower and that causes a release of moisture… commonly referred to as condensation… and that causes
rust and corrosion.

Two Important Pipe Insulation Concepts to Understand
It is important to note here that “warm” and “cool” or “hot” and “cold” are relative terms. If “hot” is a pipe that is 200°C and
the surrounding environment is 100°C, although we would consider the 100°C to be hot, in the context of the thermal
system… it is cool.
The most basic law of heat transfer is that heat always flows to cold. Warmer air can hold more moisture than colder air.
When the warm air is quickly cooled by its encounter with the pipe insulation which reduces the rate of heat transfer…
moisture is released or, to put it another way, condensation occurs.

Heat transfer is not necessarily correlated to air movement. Heat energy moves through matter… metal, insulation, air,
etc. An analogy is a wave rolling into the beach. What you see is not the actual water moving to shore (as can be
demonstrated by the fact that a boat or a piece of floating debris does not move forward with the wave… just up and
down as the wave passes underneath). Heat “waves” of heat energy pass through material the same way and the
temperature of the matter is lowered as the rate of heat transfer (or the speed of the heat “wave”) is reduced. Therefore
the temperature of the air directly adjacent to the heat source (a steam pipe at a factory OR the outside air around a
cold pipe) is higher than the temperature of the air adjacent to the insulation. It doesn’t matter how small the distance is
between the insulation and the substrate, there is ALWAYS a temperature differential.
This layer of moisture remains trapped and it is not difficult to deduce what happens when you keep a constant layer of
moisture trapped against a piece of metal. It corrodes.

How does Nansulate® Prevent Corrosion Under Insulation (CUI)?

  • Nansulate® Adheres Directly to the Substrate being insulated, bonding with it. Once a substrate is coated
    with Nansulate® adhesion prevents even microscopic spaces for oxygen between the substrate and Nansulate.
    With little or no moisture trapped against the metal substrate, corrosion is prevented or greatly reduced.

  • Hydrophobic refers to the tendency of a substance to repel water. The nanocomposite which constitutes
    approximately 70% of the dry film thickness of Nansulate® is highly hydrophobic. The hydrophobic performance
    characteristic of the nanocomposite in Nansulate® repels moisture from the coating itself, effectively creating a
    moisture free barrier against the pipe or tank or piece of equipment being insulated.

  • Coastal & Offshore Facilities like bridges, petroleum refineries and supertankers experience severe service
    environments where the constant salt air and salt spray can destroy structures and equipment fast. The
    hydrophobic performance qualities of Nansulate® repel the attempt by salt water to penetrate through to the
    substrate, preventing rust and corrosion caused by the severe service conditions.








Corrosion Defined
"Corrosion is deterioration of essential properties in a material due to reactions with its surroundings. In the most
common use of the word, this means a loss of an electron of metals reacting with water or oxygen. Weakening of iron due
to oxidation of the iron atoms is a well-known example of electrochemical corrosion. This is commonly known as rust. This
type of damage usually affects metallic materials, and typically produces oxide(s) and/or salt(s) of the original metal.
Corrosion also includes the dissolution of ceramic materials and can refer to discoloration and weakening of polymers by
the sun's ultraviolet light.

Most structural alloys corrode merely from exposure to moisture in the air, but the process can be strongly affected by
exposure to certain substances... Corrosion can be concentrated locally to form a pit or crack, or it can extend across a
wide area to produce general deterioration. While some efforts to reduce corrosion merely redirect the damage into less
visible, less predictable forms, controlled corrosion treatments such as passivation and chromate-conversion will
increase a material's corrosion resistance"

Reference: Wikipedia       

Intellectual Property Policy: Industrial Nanotech, Inc. and our partners in nanoechnology research vigorously defend the rights to our
intellectual property and immediately pursue all available remedies against any and all attempts at infringement.
North Bay Nano