DWV Pipe vs PVC: Drain-Waste-Vent Differences You Should Know
What is a DWV Pipe?
A DWV Pipe is part of a drainage, waste, and vent system in plumbing. It includes pipes that are used to carry wastewater and waste materials from sinks, toilets, and other fixtures to a septic tank or municipal sewer system. DWV pipes also allow air to enter the system, preventing pressure buildup and ensuring the smooth flow of waste.
These pipes are typically made of various materials, such as PVC, ABS, and cast iron, and they must comply with specific codes and regulations that govern plumbing systems.
Code and Standards for DWV Pipes
DWV pipes are regulated under plumbing codes to ensure that they are safe, durable, and effective in their role. Codes such as the International Plumbing Code (IPC) or Uniform Plumbing Code (UPC) specify the dimensions, materials, and installation methods of DWV systems. These codes are designed to ensure the safe and efficient removal of waste and to avoid blockages, leaks, or other problems.
What is PVC Pipe?
PVC Pipe stands for Polyvinyl Chloride pipe. PVC is a type of plastic polymer that is used in a variety of plumbing and construction applications. Known for its strength, durability, and low cost, PVC is commonly used for water distribution, irrigation, and drainage systems. PVC pipes are lightweight, easy to install, and resistant to corrosion, making them an ideal choice for both residential and commercial plumbing.
Although PVC pipes are commonly used in DWV systems, not all PVC pipes are suitable for this application. To be used in DWV systems, PVC must meet the standards outlined by ASTM (American Society for Testing and Materials), specifically ASTM D2665 for DWV systems.
Material Differences Between DWV and PVC Pipes
The main distinction between DWV pipes and PVC pipes lies in their function. While DWV pipes refer to a class of plumbing pipes used in drainage systems, PVC pipes are a specific material that can be used for a variety of applications, including as part of a DWV system.
PVC Pipes in DWV Systems
PVC is one of the most popular materials used in DWV systems. In fact, many DWV systems are constructed entirely from PVC pipes due to their numerous benefits. PVC pipes are lightweight, affordable, and easy to work with, which makes them ideal for both DIY and professional plumbing installations.
The smooth interior surface of PVC pipes also helps to reduce the likelihood of clogs, as debris is less likely to accumulate inside. Additionally, PVC pipes are resistant to corrosion, which is important for pipes that carry wastewater and waste materials.
Other Materials for DWV Pipes
In addition to PVC, other materials commonly used for DWV pipes include ABS (Acrylonitrile Butadiene Styrene), which is known for its strength and resistance to impact, making it a good option for DWV systems in colder climates. Cast iron pipes have been used in plumbing for decades due to their strength and durability. They are ideal for heavy-duty applications but are heavier and more difficult to install than PVC. CPVC (Chlorinated Polyvinyl Chloride) is similar to PVC but is designed to withstand higher temperatures. It is used in hot water systems but may also be employed in DWV systems when required.
Uses of DWV and PVC Pipes
Both DWV and PVC pipes serve different purposes depending on the requirements of the plumbing system. Let’s look at the typical uses for each type of pipe.
Uses of DWV Pipes
DWV pipes are specifically designed for use in drainage, waste, and vent systems. Their primary function is to carry wastewater and waste products away from various fixtures in a building to a sewer or septic system. This includes waste from sinks, bathtubs, toilets, dishwashers, and other appliances. DWV systems also include vent pipes, which are essential for preventing pressure buildup within the system and maintaining proper airflow.
Uses of PVC Pipes
PVC pipes, on the other hand, are used for a broader range of applications. While they are commonly used in DWV systems, they can also be employed in water distribution systems, irrigation systems, electrical conduits, and other drainage applications. Their versatility and resistance to corrosion make them suitable for many different construction and plumbing needs.
Installation Considerations
The installation of DWV and PVC pipes can vary based on the type of system being set up, but both share some common features. PVC pipes used in DWV systems must be installed according to local plumbing codes, with careful attention paid to the slope of the pipes and the sealing of joints.
For PVC pipes, a solvent cement is typically used to bond the pieces together, ensuring airtight seals at all joints. DWV systems that use PVC pipes are often installed with a slight downward slope to facilitate the proper flow of waste. Proper venting is also crucial, as it allows air to enter the system and equalizes the pressure, helping to prevent clogs and backups.
When installing any DWV system, including one made from PVC, it is important to ensure that the pipes are properly supported, particularly in longer horizontal runs. Using brackets or hangers at regular intervals will help prevent sagging or movement over time.
Cost of DWV and PVC Pipes
The cost of both DWV and PVC pipes can vary depending on the material, size, and location. PVC pipes tend to be less expensive than some other materials like cast iron, but the overall cost of a DWV system will depend on the specific needs of the installation. PVC pipes are generally affordable and easy to work with, making them an attractive option for both DIY and professional plumbing projects.
Cast iron pipes, while extremely durable, are more expensive and require specialized tools for installation. ABS pipes can be slightly more costly than PVC but may be necessary in specific environments where impact resistance or cold-temperature flexibility is required.
FAQs about DWV and PVC Pipes
What is the primary difference between DWV pipes and PVC pipes?
DWV pipes refer to pipes used in drainage, waste, and vent systems. PVC pipes are a type of plastic pipe used in plumbing systems, including DWV systems, but also for other applications like water distribution and electrical conduits.
Can PVC pipes be used for hot water systems in DWV applications?
PVC pipes are not suitable for carrying hot water in most systems, as they can warp or degrade under high temperatures. For hot water systems, CPVC pipes are typically recommended instead of standard PVC.
Are DWV pipes and PVC pipes the same thing?
No, DWV pipes refer to a category of pipes used in drainage and vent systems, and they can be made from various materials, including PVC, ABS, and cast iron. PVC is just one material that is commonly used for DWV applications.
How long do PVC pipes last in DWV systems?
PVC pipes in DWV systems can last for decades if properly installed and maintained. Their resistance to corrosion and wear helps ensure a long lifespan, especially in areas with non-aggressive wastewater.
Is it necessary to vent a DWV system when using PVC pipes?
Yes, proper venting is essential in all DWV systems, including those using PVC pipes. Vent pipes allow air to enter the system and prevent pressure buildup, ensuring the efficient flow of waste and preventing clogs.
