What is measured as a differential pressure drop across an opening in the feedwater supply piping?

What is measured as a differential pressure drop across an opening in the feedwater supply piping?

• A. Feedwater flow rate
• B. Temperature
• C. Pressure
• D. Conductivity

Answer: (A)

The differential pressure across a restriction in the feedwater line is used to determine how much water is flowing. When fluid passes through a small opening, its velocity increases and the static pressure drops across that restriction. The larger the flow, the greater the pressure drop. By applying the fluid-flow relationship for an orifice or similar restriction, you convert that pressure difference into a flow rate. That’s why this measurement is a way to gauge feedwater flow rate. It isn’t a direct measure of temperature, system pressure, or conductivity, which would require different sensors.

The differential pressure across a restriction in the feedwater line is used to determine how much water is flowing. When fluid passes through a small opening, its velocity increases and the static pressure drops across that restriction. The larger the flow, the greater the pressure drop. By applying the fluid-flow relationship for an orifice or similar restriction, you convert that pressure difference into a flow rate. That’s why this measurement is a way to gauge feedwater flow rate. It isn’t a direct measure of temperature, system pressure, or conductivity, which would require different sensors.