Heat Exchanger Maintenance

Equipment Maintenance in the Steel Industry

In the steel and metal processing industry, critical equipment such as heat exchangers plays a vital role in maintaining efficient operations. However, like all machinery in harsh industrial environments, heat exchangers are prone to issues like abrasion, erosion, and corrosion. Regular heat exchanger maintenance is essential to prevent these problems, ensuring equipment longevity and operational efficiency. Devcon offers advanced metal repair composites and durable protective coatings designed to minimize downtime and extend the service life of industrial equipment.

Heat Exchanger Maintenance in Steel Manufacturing: Addressing Galvanic Corrosion

A recent heat exchanger maintenance project in China demonstrated the effectiveness of Devcon’s solutions in addressing galvanic corrosion on the tube face of a heat exchanger. This type of corrosion arises when dissimilar metals come into contact in the presence of an electrolyte, accelerating the deterioration of one metal. The heat exchanger, a critical component in the steel manufacturing process, was experiencing compromised performance due to this issue.

Understanding Galvanic Corrosion

Galvanic corrosion occurs when two dissimilar metals are in contact and exposed to an electrolyte, such as moisture or chemical solutions. This interaction causes one of the metals to corrode more rapidly than it would in isolation. In this case, the tube face made of carbon steel was severely affected, jeopardizing the heat exchanger’s reliability and efficiency.

Application Method: In-Situ Heat Exchanger Maintenance with Devcon

To resolve the issue, the maintenance process was conducted in situ, using Devcon’s high-performance repair and protective products. Following best practices outlined in similar application guides, the process involved:

1. Preparation
   The repair area was precisely marked, and the tube face was grit-blasted to SA2.5 standards, achieving a minimum surface profile of 75 microns (3 mils). This meticulous preparation was crucial for ensuring proper adhesion of the repair materials.
2. Rebuilding the Tube Face
   Devcon Plastic Steel® Epoxy 10110, a high-strength metal repair composite, was used to rebuild the damaged and worn areas of the tube face. This product is designed to restore the structural integrity of metal components with superior durability.
3. Coating Application
   Two coats of Devcon Brushable Ceramic were applied, with each layer achieving a thickness of 250-375 microns (9.84-14.76 mils). This ceramic-filled epoxy coating provides excellent resistance to abrasion and chemical attack, ensuring long-term protection against further corrosion.
4. Inspection and Touch-Ups
   After curing, the repaired area underwent a thorough visual inspection. Any imperfections were abraded and re-coated to achieve a consistent, high-quality finish.
5. Hydrostatic Testing
   Finally, the heat exchanger underwent hydrostatic testing under 30 kg/cm² (426.7 psi) to verify the integrity and durability of the repair. The testing confirmed that the heat exchanger was ready for reliable operation.

Results: Improved Efficiency and Reduced Downtime

The in-situ application of Devcon products offered significant benefits, eliminating the need for disassembly and minimizing operational downtime. The customer expressed satisfaction with the results, noting that the repairs not only resolved the corrosion issue but also enhanced the overall efficiency of the heat exchanger.

Devcon’s advanced maintenance solutions have proven to be an effective choice for addressing common challenges like galvanic corrosion in the steel and metal processing industry. By offering robust protection and reducing maintenance-related disruptions, these solutions help companies