The Many Benefits of Lay-Ups for Power Plants

Power processing facilities experience billions of dollars of corrosion-related damage on metal and alloy materials each year. Allowing corrosion to persist can lead to operating failures, which can have fatal consequences. Power plant lay-ups are one of the methods that plant operators use to prevent corrosion. The protective measures are most effective when applied consistently and continuously.

Advantages of Using Humidity Control for Power Plant Lay-Ups

• Improved worker safety: Lay-up practices to prevent corrosion damage in the equipment that runs through work areas mitigates catastrophic failures that could injure or kill workers. Using desiccant dehumidifiers protects equipment without the health risks posed by nitrogen blankets. 
• Maintain the chemical integrity of water/steam cycles during standby periods:The goal of a facility lay-up is generally the same as chemical conditioning program: prevent, control or reduce corrosion and the buildup of deposits. Corrosion control helps maintain the integrity of boiler tubes and steam turbines.
• Increase a unit’s service life: Lay-ups can prolong a cycling unit’s life, makes it more reliable, and preserves a greater number of stream and water circuits. When performed correctly, a lay-up prevents water from contacting oxygen in drums, headers and boiler drums. It also allows older peaking and cycling units to perform reliably in operating modes that require extended downtimes or many starts per year. 
• Prevent corrosion fatigue: Corrosion fatigue is one of the main causes of boiler tube failures. With every cycle, the protective layer of magnetite oxide in cycling unit’s components crack, exposing metal surfaces to the boiler’s water. The resulting pitting aggravates other types of damage that the corrosion caused. Humidity control during a lay-up mitigates this damage and can save thousands of dollars.
• Bring equipment back online faster: When failing to use humidity control measures during a lay-up, corrosion can quickly turn a short-term outage into a long-term outage. Humidity control makes scheduled outages more reliable and predictable.
• Enhance convenience: Convenience is an important factor when considering a lay-up. Custom-built temporary humidity control solutions make it simpler to maintain ideal environments and give workers easy access to a system and its components.
• Fast plant shutdowns and reactivations: Humidity control solutions that use desiccant dehumidifiers instead of inert gases or harmful chemicals hasten the lay-up process.
• Improved water quality: Reducing corrosion on steam-side components greatly improves water quality, preserve’s a line’s thickness and prevents incidents caused by high pressure during reactivation.
• Improve the performance of surface coatings: Temporary environmental controls allow surface cleaning and the application of protective coats to proceed on schedule, despite humid conditions. The predictability gained saves thousands of dollars in coating costs and prevents unscheduled outages due to coating failures.

Effective power plant lay-ups do not put the equipment at an increased risk of corrosion damage. The techniques used should reduce chemical oxidation, prevent the environment from oxygenating water, keep water-touched surfaces dry, and keep moisture out of steam-touched components. The custom temporary humidity control solutions from Polygon allow you to establish conditions that are favorable to deposit and corrosion prevention. These solutions give you the ability to store and protect components during in-service, shutdown and lay-up periods, as well as through startup and return-to-service phases. Talk to a specialist at Polygon to learn more about how the short- and long-term humidity control solutions safeguard important systems during a lay-up without compromising a plant’s integrity. 

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