What type of pipe is usually used for DWV (Drain, Waste, and Vent) piping?

The most commonly used pipe for Drain, Waste, and Vent (DWV) systems is black ABS (Acrylonitrile Butadiene Styrene) plastic. This material is chosen for its lightweight nature, ease of installation, and excellent resistance to chemical corrosion, which is particularly important in draining systems that may handle a variety of waste materials. ABS pipes are also known for their smooth interior surfaces, which help to reduce blockages and allow for better flow within the plumbing system.

Moreover, the properties of ABS make it less prone to cracking compared to other materials, adding to its durability in various environmental conditions. It is also readily available and cost-effective, making it a popular choice among plumbers and builders for DWV applications.

In contrast, the other materials listed, while they may have their own uses in plumbing, are not typically preferred for DWV systems due to various limitations. For example, white PVC is sometimes used in other plumbing applications but is generally not favored for DWV because it is less effective in handling heat without deforming. Flexible copper pipe is primarily used for water supply lines rather than drainage. Galvanized steel is heavy and susceptible to corrosion, making it less suitable for waste and vent systems.