When priming a pump with a separate hand-operated pump, which step is NOT necessary?

When priming a pump with a separate hand-operated pump, one of the steps that is not necessary is to close the priming valve.

During the priming process, the goal is to remove any air from the pump and ensure that it is filled with water to allow for proper operation. Closing the priming valve can prevent proper flow of water into the pump, which is counterproductive during this procedure. Instead, the priming valve typically needs to remain open to allow the water to flow into the pump until it is filled and air is expelled.

In contrast, the other steps—shutting the priming pump valve, ensuring that water is issuing from the priming pump discharge, and closing the discharge valve—are necessary actions to effectively prime the pump. These steps help to control the flow and pressure of water being introduced into the system, ensuring a successful priming phase.