What is the minimum residual pressure reading on a compound gauge when working off a pressure source?

What is the minimum residual pressure reading on a compound gauge when working off a pressure source?

• A. 140 kPa
• B. 180 kPa
• C. 100 kPa
• D. 120 kPa

Answer: (A)

When you’re drawing water from a pressure source, the line feeding the pump must stay pressurized to prevent loss of prime and to stop air from being drawn into the system. A compound gauge reading represents that pressure in the line, and the minimum residual you should have is about 20 psi, which is 140 kPa. This level keeps the pump primed and maintains a stable flow; if the line pressure drops below this, air can be sucked in, prime can be lost, and discharge flow can diminish. Higher residual pressures can occur depending on the setup, but 140 kPa is the minimum safe reading to maintain the supply.

When you’re drawing water from a pressure source, the line feeding the pump must stay pressurized to prevent loss of prime and to stop air from being drawn into the system. A compound gauge reading represents that pressure in the line, and the minimum residual you should have is about 20 psi, which is 140 kPa. This level keeps the pump primed and maintains a stable flow; if the line pressure drops below this, air can be sucked in, prime can be lost, and discharge flow can diminish. Higher residual pressures can occur depending on the setup, but 140 kPa is the minimum safe reading to maintain the supply.