College of Product Knowledge:<br>DWV Pipe And Fittings
This is an updated version of the product training course introduced by Supply House Times in 1979, authored by Don Arnold.
Unlike supply piping, drainage piping does not have a dynamic force behind it, and it is always open to the atmosphere. If you think of the old adage, "down the drain," you'll get the picture here. Gravity simply causes waste water to flow downhill (though there can be more sophisticated systems that involve mechanical assists in certain applications). Typically, you will see drainage piping included under the broad and more common category heading of "DWV." Within this category, the most common material options are plastic (typically ABS and PVC), cast iron and copper. This brings us to a point that is often confusing to newcomers in our industry. A common term used interchangeably with certain components of DWV systems is "soil pipe." Technically, soil pipe is a specific material -- cast iron -- but language habits are hard to change, and you will often hear other DWV materials being called by that name. If you're ever in doubt about what a customer is asking for, it's a good idea to clarify that point.
These are the common components of any DWV system: