Extending the Life of a Corroded & Cavitated End Suction Pump with Belzona Solutions
The Problem
A critical end suction pump used in a continuous service application suffered severe corrosion throughout its inner casing. Over time, the harsh operating environment led to pitting and rusting of the metal surfaces, significantly compromising the pump’s performance and efficiency. The client faced a pressing challenge: the need for a quick, cost-efficient repair solution that would not only restore the pump’s integrity but also extend its operational life. Adding to the urgency, the client required the repair to be executed within a minimal outage window to ensure the system’s continuous operation.
Inspection by NESL Belzona Team
Nicco’s expert service engineers conducted an in-depth inspection of the pump to evaluate the extent of damage. The assessment revealed extensive pitting and corrosion across the pump’s inner casing. The team determined that a traditional repair approach, such as replacing the pump or welding, would be time-consuming and cost-prohibitive. Instead, the team recommended a cold repair solution using Belzona composites. This method was chosen for its proven ability to restore damaged surfaces efficiently and with minimal downtime.
In pump, cavitation occurs when the hydrodynamic pressure exceeds the vapour pressure of a moving liquid. Gas bubbles form within the liquid, which thus becomes a two-phase system. These bubbles will be crushed against the metal surface at high speed, an attack that leads to cavities with rounded contours. This degradation is caused by the combination of a mechanical effect and corrosion of the metal.
Corrosion occurs due to presence of salts in sea water, while erosion occurs due to consistent dynamic activity of sea water (act as erosive agent here) over a period.
Application Situation
The client prioritized three main objectives for the repair:
- Restore the pump’s structural integrity and operational efficiency.
- Implement a solution resistant to future corrosion and erosion.
- Minimize the system’s downtime to maintain production schedules.
Given these requirements, Nicco’s engineers proposed using the Belzona 1311 (Ceramic R-Metal) and Belzona 1321 (Ceramic S-Metal) systems, which are renowned for their durability and performance in aggressive environments.
Application Method
The repair process was meticulously planned and executed as follows:
- Surface Preparation:
The corroded and pitted inner casing of the pump was thoroughly cleaned. This included grit blasting the metal surface to an SA 2.5 standard, achieving a surface profile of 75 microns. This preparation step ensured optimal adhesion of the Belzona materials to the substrate.
- Repairing the Surface:
Belzona 1311 was carefully applied to fill the pitted and rusted areas of the casing. This versatile composite material is designed to rebuild and restore metal surfaces, providing a strong and durable foundation.
- Applying the Protective Coating:
Two coats of Belzona 1321 (Ceramic S-Metal) were applied over the repaired surface. This coating system is engineered for exceptional resistance to erosion and corrosion, making it ideal for environments with high fluid flow and abrasive particles. Its relatively thin film thickness ensures that the pump’s performance is not adversely impacted by flow restrictions.
The Outcome
The repair was completed within the client’s tight outage window, allowing the pump to return to service without disrupting production schedules. The Belzona system restored the pump’s inner casing to its original profile and provided a protective barrier against future corrosion and erosion. As a result:
- The pump’s operational efficiency and reliability were fully restored.
- The repair extended the pump’s service life, significantly delaying the need for costly replacements.
- The client achieved substantial cost savings compared to traditional repair or replacement methods.
Belzona Facts
- Belzona 1311 (Ceramic R-Metal):
A highly durable repair composite used for rebuilding and restoring corroded or pitted metal surfaces.
- Belzona 1321 (Ceramic S-Metal):
A two-component epoxy-based protective coating designed for high-performance resistance to corrosion and erosion in aggressive fluid flow environments.
- Key Benefits:
- Rapid application and cure time minimize downtime.
- Thin film thickness prevents flow restrictions, ensuring optimal pump performance.
- Long-lasting protection extends equipment life and reduces maintenance costs.
This case exemplifies how Belzona composites provide innovative, cost-efficient, and reliable solutions to tackle even the most challenging repair scenarios.
If you have similar challenges or would like to discuss how advanced polymer technologies can benefit your projects, feel free to connect or leave a comment below!