Massachusetts Wastewater Practice Exam

Opening the valve all the way is a critical first step when packing a modern gate valve. This action ensures that the valve stem is fully extended, providing maximum accessibility to the stuffing box, where packing is to be installed. When the valve is open, it not only allows for better visibility and access but also prevents potential damage to the valve components during the packing process. It may also help in minimizing the risk of misalignment or binding when the packing is being applied.

Addressing the other options helps to clarify why they are not the initial steps. For instance, removing old packing from the stuffing box can only be effectively accomplished when the valve is open, and polishing the valve stem is best done with the stem fully extended for a more accurate and thorough job. Similarly, while installing new packing is important, it can only happen confidently after ensuring that the preceding steps have been conducted successfully to prevent complications during installation.