During a dry lay-up, what condition applies to all valves?

During a dry lay-up, maintaining all valves in a closed position is essential to prevent contamination and corrosion within the system. Keeping the valves closed helps to isolate the equipment and minimizes exposure to environmental factors such as moisture and air, which could lead to oxidative damage or rust in the absence of water.

In this context, valves serve as barriers. If any of the valves were open, there could be a risk of dirt, debris, or moisture entering the system, potentially leading to extensive damage or maladaptation of the equipment once it is returned to service. Therefore, ensuring that all valves are closed is a critical precaution during this process, helping to preserve the integrity and reliability of the boiler system for future use.