Journeyman Plumber ExamDrainage, Waste, and Venting (DWV) SystemsMedium
A plumber is performing a water test on a newly installed DWV system. The system includes a 30-foot stack. To what height above the highest fitting or connection must the water be maintained for the test?
- AThe top of the stack
- BNot less than 10 feet
- C5 feet
- D10 feet
Show answer & explanationAnswer & explanation
Correct answer: B. Not less than 10 feet
For a water test on a DWV system, the water must be maintained at a level not less than 10 feet above the highest fitting or connection on the stack, or to the top of the stack, whichever is lower.
Why the other options are wrong
- A. Filling to the top of a very tall stack might exceed code requirements and put unnecessary stress on the system; the 'not less than 10 feet' rule applies.
- C. 5 feet is insufficient to provide the necessary pressure for effective testing.
- D. While 10 feet is part of the rule, the full rule is 'not less than 10 feet'.
DWV Water Test Height
The minimum height to which water must be filled in a DWV system during a water test to ensure pipe integrity and seal effectiveness.
- Ensures all joints and pipes are watertight.
- Pressure must be sufficient to reveal leaks.
- Standard is 'not less than 10 feet above highest fitting'.
Memory trick: Test Tall Ten, Tight Territory.