Which of the following is NOT a step in starting up a steam system?

In a steam system startup process, it is essential to ensure that all components function correctly to maintain safety and efficiency. One critical step involves ensuring that all steam traps are operational; they must not be permanently closed. Steam traps are designed to remove condensate and non-condensable gases from the steam system while allowing steam to pass through when in good working order. If all steam traps are permanently closed, it would prevent the normal operation of the system, leading to issues such as water hammer, excessive pressure buildup, and potential damage to the system.

The other steps listed—reinstalling insulation, ensuring safety valves and vents are operational, and completing necessary repairs—are all standard and critical practices in preparing a steam system for startup. Insulation is crucial for maintaining heat and efficiency, safety valves and vents are necessary for pressure regulation and safety, and completing repairs ensures there are no leaks or hazards present before operation. Therefore, permanently closing all steam traps does not align with the proper protocol for starting up a steam system, making it the correct answer to the question.