Testing, Inspection & Sewage Systems
DWV water and air tests, supply pressure tests, septic systems, sewage ejectors, gray water, and building subdrains.
- Describe the DWV water test and air test procedures and minimum pressures
- State the water supply pressure test requirements
- Size septic systems and identify setback distances
- Explain sewage ejector, gray water, and subdrain requirements
Lección 1
DWV Water Test & Air Test Procedures
When Testing Is Required
All new DWV piping must be tested and inspected before it is concealed (enclosed in walls, floors, or ceilings). The three approved test methods are the water test, the air test (pneumatic), and the vacuum test. The 2024 IPC approves vacuum testing as an alternative to pneumatic air testing for DWV piping. Any of the three methods is acceptable unless the jurisdiction requires a specific one.
Water Test
Minimum head: 10 feet of water
Duration: 15 minutes minimum
Method: Fill system to highest point, maintain 10 ft head
Pass criteria: No visible leaks, no drop in level
Air (Pneumatic) Test
Minimum pressure: 5 psi
Duration: 15 minutes minimum
Method: Pressurize closed system with air
Pass criteria: No pressure drop on gauge
Vacuum Test (2024 IPC)
Method: Apply vacuum to closed DWV system
Approval: Approved alternative to pneumatic test
Advantage: Eliminates risk of pressurized fitting failure
Pass criteria: Vacuum holds without loss
Water Test Details
The DWV water test requires filling the system with water to achieve a minimum of 10 feet of water head above the highest point being tested. The system must hold this water level for at least 15 minutes with no visible leaks and no measurable drop in level.
Air Test Details
The DWV air test requires pressurizing the system to a minimum of 5 psi. The system must hold this pressure for at least 15 minutes with no pressure loss visible on the test gauge.
Smoke testing for leak detection:
A smoke test uses non-toxic smoke injected into the DWV system under slight pressure to identify leaks. Smoke escaping at unexpected locations (walls, floors, outside foundation) indicates a crack or open joint. Smoke testing is often used:
- To identify leaks in existing systems that cannot be water-tested without extensive disruption
- To verify trap seals are intact (smoke will exit through dry traps)
- To trace sewer odor complaints in buildings
During a smoke test, all trap seals must be primed (full of water) before the test begins, or they will appear as leaks.
Ball plug testing for large drains:
For large-diameter drains (4 inches and above), inflatable test balls are used to plug the drain at downstream test points rather than caps. The inflatable ball is inserted through a cleanout or test tee and inflated to seal the pipe. This allows precise water-level testing of specific sections without filling the entire system.
The DWV water test requires 10 feet of water head minimum. The DWV air (pneumatic) test requires 5 psi minimum. The 2024 IPC adds vacuum testing as a third approved alternative. All tests must hold for at least 15 minutes with no loss. Smoke tests locate leaks in existing systems and verify trap seals by detecting unexpected smoke escape points.