Journeyman Plumber ExamDrainage, Waste, and Venting (DWV) SystemsEasy
A plumber is inspecting a newly installed DWV system before final cover. What is the minimum required test pressure for an air test on the drainage portion of the system?
- A5 psi (34.5 kPa)
- B3 psi (20.7 kPa)
- C10 psi (68.9 kPa)
- D2 psi (13.8 kPa)
Show answer & explanationAnswer & explanation
Correct answer: A. 5 psi (34.5 kPa)
Most plumbing codes require a minimum air test pressure of 5 psi (34.5 kPa) for the drainage and vent system, held for a specified duration, typically 15 minutes, without loss.
Why the other options are wrong
- B. While closer, 3 psi is typically below the minimum required pressure for an air test.
- C. 10 psi is usually higher than required and could potentially stress the system unnecessarily, though it would certainly reveal leaks.
- D. This pressure is generally too low to adequately test for leaks in a DWV system.
DWV Air Test
A method of testing the integrity of a drainage, waste, and vent system by pressurizing it with air and observing for pressure loss.
- Detects leaks in pipes and fittings.
- Requires all openings to be sealed.
- Typically held for 15 minutes without pressure drop.
Memory trick: Pressure checks are key, for a leak-free guarantee!