Which statement about static pressure is true?

Which statement about static pressure is true?

• A. Static pressure is the system pressure with no flow.
• B. Static pressure is the pressure when water is flowing.
• C. Static pressure is the maximum system pressure at startup.
• D. Static pressure is irrelevant to pump operation.

Answer: (A)

Static pressure is the pressure in the piping when the water is not moving. It’s the reading you get on a pressure gauge when flow is stopped (valves closed), so there’s no velocity head contributing to the measurement. This resting pressure is what pumps must be able to overcome to push water through the system, and it’s a key part of determining pump head. When water is flowing, some pressure exists to drive the flow, but that is not static pressure—the dynamic (velocity) component adds to or changes the reading. Therefore, the statement that static pressure is the system pressure with no flow is the accurate description. The other ideas don’t fit: static pressure isn’t defined by flow conditions, startup maximum, or something irrelevant to pump operation.

Static pressure is the pressure in the piping when the water is not moving. It’s the reading you get on a pressure gauge when flow is stopped (valves closed), so there’s no velocity head contributing to the measurement. This resting pressure is what pumps must be able to overcome to push water through the system, and it’s a key part of determining pump head. When water is flowing, some pressure exists to drive the flow, but that is not static pressure—the dynamic (velocity) component adds to or changes the reading. Therefore, the statement that static pressure is the system pressure with no flow is the accurate description. The other ideas don’t fit: static pressure isn’t defined by flow conditions, startup maximum, or something irrelevant to pump operation.