Polyvinyl chloride (PVC) piping is the main type of piping used in water distribution systems throughout the world. Miles of underground PVC water piping carry fresh water from water treatment plants to homes and businesses. Smaller PVC pipes then distribute the water to sinks, showers, and other fixtures throughout the building or residence.
The use of PVC pipe to distribute water dates back only as far as the 1960s. Before that time, water was carried through metal pipes, which were mostly made from lead. By the 20th century, as the dangers of lead became apparent, cities switched to the use of iron or copper pipes. Both of these materials are relatively expensive, however, so scientists began to experiment with PVC. At the time, PVC was a relatively new substance, whose main use was in creating strong and durable tire treads.
Since that time, the PVC water pipe has quickly become the standard in the industry, offering many advantages over alternative pipe materials. PVC water pipe is incredibly strong and durable, especially when compared to its relatively low weight. The low weight of PVC water pipe allows installers to work much more quickly than if they were working with iron or copper piping, which results in lower labor costs. PVC water pipes are also very smooth, which means there is no loss of flow or water pressure due to friction. Finally, PVC water pipe does not react chemically with water, so there is little risk of rust or corrosion.
There are three types of PVC water pipe that are commonly used in modern systems. The most common is simply called rigid PVC piping. This material is suitable for carrying cold water or waste water, and can be used in virtually any size that is required. Chlorinated polyvinyl chloride (CPVC) is used for carrying hot water, or water that is under high pressure. Polybutlyene (PBT) is a smaller, flexible gray or black pipe that is used for exposed areas or risers.
PVC water pipe is described by both diameter and thickness. The diameter of PVC pipe is given in Nominal Pipe Size (NPS), the North American standard for measuring pipes. It was developed in the 1920s to give installers from different regions or countries a way to connect water systems to one another successfully. The thickness of the pipe is referred to by its “Schedule,” with Schedule 40, the most common type, having a wall thickness of 0.237 inches (6.02 mm). The higher the pipe's schedule value, the thicker and stronger the pipe.
