What conditions must be met for an internal high-pressure inspection of a boiler?

For an internal high-pressure inspection of a boiler, specific conditions need to be met to ensure safety and thorough evaluation. The correct conditions require that the boiler be shut down, completely drained, and that any necessary openings, such as hand holes and manholes, be removed to allow access for inspection. This process is critical because inspecting a pressurized boiler can pose significant risks, including the danger of steam or hot gases escaping. Drainage ensures that no residual water can generate steam or cause violent reactions upon inspection.

The removal of hand and manholes provides essential access to the internal components of the boiler. A clean interior is also vital, as it allows inspectors to see any issues that may not be visible if debris or residual materials are present. These steps not only facilitate a comprehensive inspection but also comply with safety regulations in the industry, ensuring that any potential hazards are minimized.

Other options do not encompass all the necessary safety and accessibility measures required for an effective internal inspection. For example, being operational and pressurized could lead to dangerous conditions, and simply being accessible or intact does not address the critical need for draining and cleaning. Therefore, the outlined conditions in the correct choice are essential for conducting a safe and thorough high-pressure boiler inspection.