Maintenance Technician Practice Test

What is a common maximum pressure for type DWV pipes?

1. 50 psi

2. 10 psi

3. 20 psi

4. 30 psi

The correct answer is: 10 psi

Type DWV (Drain, Waste, and Vent) pipes are designed primarily for gravity flow of waste and do not typically handle pressure like supply pipes do. The maximum pressure often associated with these pipes is around 10 psi. This limit is due to the fact that DWV systems are intended to manage the flow of wastewater through gravity and atmospheric pressure rather than pressurized systems. Choosing 10 psi aligns with the design criteria of DWV systems which prevent the application of high pressure, as the main concern in these systems is to effectively drain and ventilate without risking leaks or bursts from excessive pressure. Therefore, understanding that DWV pipes are not meant for high-pressure applications is vital in recognizing why this specific pressure limit is established. This ensures the longevity and proper functioning of the plumbing system designed for waste management.