Free Journey Level Plumber Exam Questions That Helps Candidates Pass

Each flush tank water closet is rated at 2.5 fixture units. Four units equal 10 FU. According to UPC water distribution tables, a 1-inch branch line is required to handle 10 FU at standard pressure conditions. A 3/4-inch line would be insufficient, risking pressure drops during simultaneous flushing. Correct answer: C. 1 inch.

UPC water supply tables size service lines based on total fixture units. A system with 25 fixture units requires a minimum of 1-1/4 inch service at standard pressures and developed lengths. While smaller lines (1 inch) may serve fewer units, undersizing risks pressure drops and inadequate flow. Larger sizes (1-1/2 inch) would be unnecessary unless extra capacity is required. Proper sizing ensures balanced supply and code compliance. Correct answer: C. 1-1/4 inch.

Flushometer valves discharge large volumes of water quickly and require a 1-inch minimum supply line under the UPC. A 3/4-inch or smaller line cannot deliver the necessary flow and pressure. Correct answer: C. 1 inch.

UPC drainage load tables specify that a 6-inch vertical stack may carry up to 720 DFUs. Beyond this capacity, upsizing is required to ensure the stack can handle peak discharge without surcharge. Correct answer: C. 720 DFUs.

At 100 feet, a 2-inch pipe delivers ~608,000 BTU/hr, which is insufficient. A 2-1/2 inch pipe delivers ~1,150,000 BTU/hr, making it the correct choice for 1,000,000 BTU/hr. Correct answer: B. 2-1/2 inches.