Test methods for drain and vent systems require what?

• A. 10 feet head of water; air test with a uniform gauge pressure of 5 PSI or sufficient to balance a mercury column 10 inches high; hold for 15 minutes.
• B. 15 feet head of water; air test with 2 PSI; hold 5 minutes.
• C. 5 feet head of water; air test with 10 PSI; hold 30 minutes.
• D. 20 feet head of water; vacuum test; hold 60 minutes.

Answer: (A)