Copper tubing for both above and underground drainage and vent piping must have a weight of at least which type?

The correct type of copper tubing for drainage and vent piping is classified as DWV (Drainage, Waste, and Vent). DWV copper tubing is specifically designed to handle the unique requirements of drainage systems, ensuring adequate flow and resistance to corrosion typically found in wastewater environments.

This designation signifies that the tubing is appropriate for use in both above and underground applications, providing the necessary durability and thickness required to withstand pressure and the harsh conditions often encountered in drainage systems. The DWV classification is crucial for maintaining proper plumbing standards and ensuring the longevity of the piping system.

Type L and Type K are other categories of copper tubing, which are thicker and often used in situations requiring more rigid piping, such as in water supply lines and gas lines. Type M is generally the thin-walled version suitable for less demanding applications, but it does not meet the specifications necessary for drainage and venting purposes. Thus, DWV is the ideal choice for the given context.