Energy Risk Engineering Insights

Let’s discuss CUI at refineries.

CUI stands for Corrosion Under Insulation, and it is a significant challenge in refineries and other industrial facilities. CUI occurs when moisture becomes trapped between insulation material and the underlying metal surface, leading to corrosion and potential structural damage.

Refineries use insulation materials to maintain process temperatures, prevent heat loss, and protect personnel from hot surfaces. However, if the insulation system is compromised or damaged, moisture can infiltrate and create a corrosive environment. CUI is particularly problematic in refineries due to the presence of harsh chemicals, high temperatures, and various process conditions that can accelerate corrosion.

Some key factors contributing to CUI in refineries include:

1. Moisture ingress: Refineries often operate in humid or wet environments, and insulation systems can absorb moisture from the air or from process leaks, leading to CUI.
2. Insulation defects: Damage to insulation, such as cracks, gaps, or poor installation, can allow moisture to penetrate and reach the metal surface, initiating corrosion.
3. Thermal cycling: Refinery equipment experiences frequent temperature changes, causing expansion and contraction. This thermal cycling can compromise insulation integrity, creating pathways for moisture ingress and accelerating CUI.

The consequences of CUI in refineries can be severe, including equipment failure, safety hazards, environmental impacts, and financial losses due to repairs, production downtime, and potential regulatory penalties.

To mitigate CUI, refineries employ various strategies, such as:

1. Insulation selection: Using appropriate insulation materials that are resistant to moisture absorption and corrosion can reduce the risk of CUI. Insulation manufacturers offer specialized products designed for CUI prevention.
2. Insulation maintenance: Regular inspections, maintenance, and repair of insulation systems are crucial to identify and address any damage or defects that could lead to CUI. Prompt action can help prevent moisture ingress and corrosion.
3. Corrosion inhibitors: Applying corrosion inhibitors to the metal surfaces beneath the insulation can provide an additional layer of protection against CUI. These inhibitors create a barrier that mitigates the corrosive effects of moisture.
4. Coatings and sealants: Applying protective coatings and sealants on metal surfaces can enhance their resistance to moisture and corrosion. These coatings act as a barrier, preventing moisture from reaching the metal.
5. Monitoring and testing: Implementing a comprehensive inspection and monitoring program using techniques like non-destructive testing can help detect early signs of CUI. Regular monitoring allows refineries to identify potential problem areas and take preventive measures.

It’s worth noting that CUI prevention requires a multi-faceted approach, combining engineering controls, regular maintenance, and best practices throughout the facility. The goal is to minimize moisture ingress, identify vulnerabilities, and implement appropriate measures to protect against CUI in refineries.