Refer to the whole house gas piping drawing. Use demand as specified in the Code except for the furnace (110,000 BTUH); Gas log 25,000; 40 gallon hot water heater. What is the minimum pipe size required at the output side of the second stage regulator?

Refer to the whole house gas piping drawing. Use demand as specified in the Code except for the furnace (110,000 BTUH); Gas log 25,000; 40 gallon hot water heater. What is the minimum pipe size required at the output side of the second stage regulator?