New York Low Pressure Boiler COF Practice

What must be done when adding a new tube to a water tube boiler?

1. Drill and expand

2. Roll and flare

3. Cut and seal

4. Weld and bond

The correct answer is: Roll and flare

When adding a new tube to a water tube boiler, the process typically involves rolling and flaring the tube. This method is crucial because it ensures a proper seal between the tube and the boiler's tubing sheet, which helps maintain the integrity and functionality of the boiler system. Rolling refers to the mechanical process where the end of the new tube is rolled into the fitting to create a tight fit. This helps to prevent leaks and ensures good thermal conductivity. Flaring involves expanding the end of the tube slightly, which further enhances the surface contact between the tube and the boiler components, providing additional strength to the connection. This dual-action process is essential for maintaining the high-pressure environment typical in water tube boilers, where even minor leaks can lead to significant safety hazards and efficiency losses. Other options might involve methods that could compromise the boiler's efficiency or safety. For instance, drilling and expanding may not provide the same level of sealing capability, while cutting and sealing could introduce potential failure points. Welding can be used in some applications, but it is more common in specific repair scenarios rather than in the initial installation of a new tube. Thus, rolling and flaring is the standard practice for adding new tubes in water tube boilers to ensure longevity and performance.