Simple corrosion prevention strategies not only minimize complications such as clogging and high iron levels at startup but also offer long-term benefits by discouraging the onset of leaks and promoting a longer asset service life overall.
Northern Hemisphere: Best Practices for Cooling System Layup and Boiler Startup
For many, cooling tower winterization or chiller layup mean little more than shutting down the system and hoping for the best. However, without standard water treatment chemistry circulating through the system, the metal surfaces are vulnerable to corrosion that will gradually eat away at the asset, thinning the walls and releasing corrosion products into the water year after year. Adding a simple treatment such as the Cortec® Cooling Loop Gator® prepares the system for wet or dry layup. Circulating these film-forming corrosion inhibitors through the system for 12-24 hours leaves behind a protective layer that offers protection above and below the water level (as long as the system remains closed) and does not need to be removed at startup.
Boilers are often brought back online at the same time cooling water systems are shut down, when the need for residential and commercial cooling gives way to heating demands. Boilers are especially vulnerable to corrosion as fresh, unheated, highly oxygenated water floods the system before the normal operating water treatment chemistry program is in place. Pitting corrosion is common and can easily be counteracted by adding a Boiler Egg™ to the boiler before startup. This water-soluble pouch dissolves in the makeup water, releasing active chemistry that scavenges oxygen and passivates metal surfaces in the critical startup phase. It also has NSF G7 certification for use in food processing areas where the treated water or steam has no food contact.
Southern Hemisphere: Boiler Layup and Cooling System Startup Tips
Those south of the equator are experiencing the opposite seasonal change and need to think about boiler winterization and cooling system commissioning. In this case, boiler layup can be simplified by applying the VpCI® Gecko™, Boiler Lizard®, or VpCI® Dragon™ (depending on boiler size) to drained boilers and closing all openings to trap Vapor phase Corrosion Inhibitors within the space. In many cases, the boiler can be restarted without product removal. Boilers undergoing wet layup can be treated with the VpCI® Chameleon™, a corrosion inhibiting blend that includes NSF G6 certification for use in food industry boilers where steam may come into contact with food.
The Cooling Loop Croc™ is the Boiler Egg’s counterpart for cooling system startup. It is an excellent option for both a full return to service and temporary startup during winter warm spells. The Cooling Loop Croc™ comes in water-soluble bags that can be added to a turbulent area of the cooling tower basin after partially filling the system with water and turning on the circulating pumps. The Croc dissolves and releases multi-metal corrosion inhibiting chemistry for the protection of both ferrous and yellow metals.
- Cooling Loop Gator®Prepares the system for wet or dry layup
- Boiler Egg™Water-soluble pouch dissolves in the makeup water, releasing active chemistry that scavenges oxygen and passivates metal surfaces
- Cooling Loop Croc™The Boiler Egg’s counterpart for cooling system startup
- VpCI® Gecko™, Boiler Lizard®, VpCI® Dragon™Applied to drained boilers (depending on boiler size)
- VpCI® Chameleon™A corrosion inhibiting blend that includes NSF G6 certification for use in food industry boilers
- NSF G7 CertificationFor use in food processing areas where the treated water or steam has no food contact
A Valuable Addition to the Seasonal Shutdown/Startup Checklist
Adding corrosion protection to the seasonal shutdown and startup checklist is a relatively small step that promises significant returns in terms of headaches avoided and repairs and replacements delayed. Contact Cortec® Corporation for additional best practices on avoiding boiler and cooling system corrosion during critical shutdown and startup phases: https://www.cortecwatertreatment.com/contact-us/.
