The initial cross-connection test uses which system pressure?

The initial cross-connection test uses which system pressure?

• A. 7.5 psig
• B. 10.0 psig
• C. 12.0 psig
• D. 14.7 psig

Answer: (D)

When checking a cross-connection, you begin with a neutral pressure so you can see if backflow would occur without any extra push from the supply. This neutral baseline is the atmospheric pressure, which is about 14.7 psi in absolute terms. Using this starting pressure ensures there’s no pressure differential driving water back toward the supply, so any observed leakage or backflow indicates the device isn’t performing properly. If you started at a lower or higher gauge pressure, you’d introduce a differential from the outset, making it harder to judge the device’s true ability to isolate the potable system. That’s why the initial cross-connection test uses the standard atmospheric pressure of 14.7 psi.

When checking a cross-connection, you begin with a neutral pressure so you can see if backflow would occur without any extra push from the supply. This neutral baseline is the atmospheric pressure, which is about 14.7 psi in absolute terms. Using this starting pressure ensures there’s no pressure differential driving water back toward the supply, so any observed leakage or backflow indicates the device isn’t performing properly. If you started at a lower or higher gauge pressure, you’d introduce a differential from the outset, making it harder to judge the device’s true ability to isolate the potable system. That’s why the initial cross-connection test uses the standard atmospheric pressure of 14.7 psi.