Final air test is equivalent to a _______ inch water column, and it shall be maintained for atleast _______ minutes.

Final air test is equivalent to a _______ inch water column, and it shall be maintained for atleast _______ minutes.

• A. 1 inch; 15 minutes
• B. 2 inch; 15 minutes
• C. 1 inch; 30 minutes
• D. 2 inch; 30 minutes

Answer: (B)

The test uses a small, controlled air pressure to check for leaks in the drainage-vent system. By pressurizing the system to 2 inches of water column, you’re applying enough pressure to reveal weak joints without stressing the pipes or trapping water in traps. Maintaining that pressure for 15 minutes gives time for any slow leaks to become evident. If the pressure stays essentially unchanged during the period, the system is considered leak-free. In common practice, 2 inches of water column is a standard, safe test level, and 15 minutes is long enough to verify stability without being unnecessarily long. That’s why the correct choice uses 2 inches of water column for 15 minutes.

The test uses a small, controlled air pressure to check for leaks in the drainage-vent system. By pressurizing the system to 2 inches of water column, you’re applying enough pressure to reveal weak joints without stressing the pipes or trapping water in traps. Maintaining that pressure for 15 minutes gives time for any slow leaks to become evident. If the pressure stays essentially unchanged during the period, the system is considered leak-free. In common practice, 2 inches of water column is a standard, safe test level, and 15 minutes is long enough to verify stability without being unnecessarily long. That’s why the correct choice uses 2 inches of water column for 15 minutes.