If you asked the average person what color PVC pipe was, they would say white. It would be easy to assume that all PVC pipe is white because that is the most common form that it appears. It actually comes in several different colors, all for very different purposes. Below is a list of colors and what purpose each color serves not only in irrigation, but also other trades. It is important to know your colors so you don’t make the mistake of using the wrong color or connecting to something wrong in an installation
White: This is standard PVC that is used to transport potable water. White comes in Class and Schedule which are different classifications of pipe. Please read my blog on Class VS. Schedule if you want to learn more. Typical application for white PVC is domestic water and irrigation water transportation that is buried in the ground.
Brown: This pipe has been infused with a UV inhibitor so it can remain above ground. It is referred as brown line because of it’s off-white appearance but it is classified as Schedule UV PVC. PVC pipe get’s brittle if it is left in the sun for too long. Brown line resists the effects of the sun so it is used in above-ground applications. Common above-ground applications are slopes and hillsides where burying the pipe is very difficult due to the working conditions of a slope.
Purple: This pipe is used to transport non-potable or reclaimed water. This pipe is classified as Reclaimed Schedule PVC. Although the purple does not change the nature of the pipe like brown pipe, it is a warning to the public that the water running through those pipes is not safe for human consumption. You will see this pipe commonly used on new developments because the use of reclaimed water for irrigation has become mandatory for many cities and counties for new development. If an irrigation system is reclaimed, it will also be accompanied with signage and all of the valve boxes will be purple as well.
Gray: Classified as Schedule Conduit, this pipe is used exclusively in the electrical trade. Although the gray does not change the nature of the pipe, it is a warning to the public that there are electrical wires running through the pipe. You may see this pipe commonly attached to an electrical junction box but it is rarely seen above ground.
Black: You will never see this pipe above ground because it is used to transport waste in the form of storm run-off or sewage. This pipe is classified as Schedule CPVC and is of a large diameter (1 ½” or larger). There is another form of black pipe that is not PVC and is used to transport nuisance natural gas. We will not explore this pipe for it is not commonly encountered and this author knows very little about it.
Light Blue: Very few people have seen this pipe because it comes in very large diameter (12” or larger) and is used for sewage line buried very deep. Unlike all other PVC, this pipe is not glued together, it is connected with rubber gaskets and is always installed as a double wall for safety purposes.
This covers the basics of color PVC pipe. There are several other color pipes as indicated in the attached picture but most you will never encounter. The pipes listed above (with the exception of the light blue) are available at most hardware stores or irrigation supply stores. Knowing what the application of the project is will help you make an intelligent decision but make sure you do your research before starting any project.