← Backflow Prevention – Plumber Journeyman Exam Flashcards

Plumber Journeyman Exam Sample Test

Try 5 free practice questions with instant feedback. See how ready you are.

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Sample Questions

Question 1

What is backflow in a plumbing system?

Answer: Backflow is the undesirable reversal of flow of water or other substances from any source back into the potable water distribution system.

Question 2

What is the difference between backsiphonage and backpressure?

Answer: Backsiphonage is caused by negative pressure (partial vacuum) in the supply line, while backpressure occurs when downstream pressure exceeds the supply pressure.

Question 3

What is a cross-connection in plumbing?

Answer: A cross-connection is any physical link between a potable water supply and a source of contamination or pollution that could allow backflow to occur.

Question 4

What is an air gap, and what degree of hazard does it protect against?

Answer: An air gap is the unobstructed vertical distance between the lowest opening of a water supply outlet and the flood level rim of a fixture. It is the highest level of backflow protection and protects against both high and low hazard conditions.

Question 5

What minimum air gap is required between a potable water outlet and the flood level rim of a fixture for a 1-inch pipe?

Answer: A minimum air gap of 2 inches (twice the diameter of the supply pipe, but not less than 1 inch) is required for a 1-inch pipe under most codes.