A pressure reducing valve is defined as a normally closed valve. Is this statement true?

A pressure reducing valve is designed to control the pressure of a fluid downstream of the valve by reducing the pressure from an upstream supply. Typically, these valves are referred to as "normally open" devices because they allow flow to pass through them until the downstream pressure rises to a set point, at which time they close to reduce the flow and maintain the desired pressure.

The design of a pressure reducing valve ensures that when the downstream pressure falls below a certain threshold, the valve opens to allow more fluid to flow and maintain pressure. This behavior contrasts with a normally closed valve, which would remain closed until activated to allow flow. Therefore, the characterization of a pressure reducing valve as a normally closed valve is inaccurate. Thus, the correct answer is that the statement is false.