Reviewed by: Hady Makhmalbaf Ph.D., PE, Sr. Mechanical Engineer
Plumbing pipes are responsible for carrying fresh water to fixtures and appliances, and they also play a role in the drainage of wastewater. There are a variety of different types of plumbing pipes available on the market, each with its own set of advantages and disadvantages. In this article, we will review the types of piping and their unique properties.
Types of Plumbing Pipes
Here is a breakdown of what each pipe material is and what its unique properties are.
Copper pipes are a type of tubing that is frequently used in plumbing. They are made from a ductile metal that is resistant to corrosion, making them an ideal choice for carrying potable water. Copper pipes can handle high pressure, are very durable, and come in 4 types as shown in the table below. The most commonly used type in residential plumbing is Type-L.
|Type||Fitting Methods||Flexible Form Available||Common Use|
|Type K||Soldered, Compression, Push-fit, Press-connect, Flare (flexible pipe)||Yes||Main water lines, underground lines|
|Type L||Soldered, Compression, Push-fit, Press-connect, Flare (flexible pipe)||Yes||Branch water supply lines|
|Type M||Soldered, Compression, Push-fit, Press-connect||No||Branch water supply lines|
|DWV||Soldered, Slip-joint||No||DWV plumbing lines|
Polyvinyl Chloride (PVC) Pipe
PVC (Polyvinyl chloride) pipes are rigid plastic pipes that are chemical-resistant. They are NOT heat resistant, and can only operate up to 120 degrees to 140 degrees Fahrenheit. These pipes come in a few different thickness sizes, with Schedule 40 being the most common thickness for pressure systems. PVC pipes are commonly found in the United States and are primarily used as sewer pipes, drain taps, and DWV (drain, waste, and vent) pipes.
Chlorinated polyvinyl chloride (CPVC) Pipe
CPVC pipe is a type of plastic piping that is widely used for plumbing and irrigation applications. CPVC is made from PVC that has been treated with chlorination, which gives it increased resistance to chemicals and temperatures. CPVC has a maximum working temperature of 200 degrees Fahrenheit. CPVC pipes are primarily used for hot and cold water plumbing distribution and can be seen in both residential and commercial buildings.
Acrylonitrile Butadiene Styrene (ABS) Pipe
ABS pipes are a type of plastic pipe that is commonly used in plumbing. The abbreviation “ABS” stands for acrylonitrile butadiene styrene, which is the material that the pipes are made from. ABS pipes are known for being durable and easy to work with, making them a popular choice for home renovation projects. However, ABS pipes can also be brittle and may crack if they are exposed to too much cold or heat. In addition, ABS pipes are not compatible with all types of pipe fittings, so it is important to check compatibility before beginning a project.
Galvanized Steel Pipe & Cast Iron Pipes
Galvanized steel pipe is a type of plumbing pipe that is commonly used in residential and commercial construction. This type of pipe is made from a steel sheet that is hot dipped in a zinc-based galvanizing process. This process coats the steel with a layer of zinc that helps to protect it from corrosion.
This type of piping material comes in higher prices. The fitting and labor are also more expensive. To give an example, a bathroom renovation with galvanized steel pipe costs almost twice as much as PEX. However, a higher pressure rating, corrosion resistance nature, and some other features make galvanized steel pipe suitable for many high-rise residential and commercial applications.
Galvanized steel pipes are primarily used for carrying water or gas. However, they can also be used for carrying other liquids such as sewage, oil, or even certain chemicals.
Cast-iron pipe is a type of piping that is commonly used in plumbing applications. It is made by pouring molten iron into a mold, and as it cools, the iron forms a strong, durable pipe. One of the benefits of using cast-iron pipe is that it is very resistant to corrosion. This makes it an ideal choice for carrying water and other liquids through a home or business. Additionally, cast-iron pipe is often used in sewer applications because it can withstand the corrosive effects of sewage. However, one downside of using cast-iron pipe is that it is very heavy, making it difficult to transport and install. Yet, many developers use this method for both domestic water and sewage from coast to coast. It’s not uncommon to see high-rise buildings over 60 years of age still operating with the original cast-iron piping.
PEX piping is a type of tubing made from cross-linked high-density polyethylene. It is commonly used in plumbing and radiant heating applications. PEX piping is flexible, durable, and easy to install, making it an ideal choice for a wide variety of projects. It is also resistant to certain chemicals and can withstand high temperatures, making it an ideal material for hot water lines. PEX piping is available in a variety of sizes and colors, making it easy to find the perfect fit for any project.
Terracotta Sewer Pipe
Terracotta sewer pipes are a type of tubing that was commonly used for drainage and sewer applications. It is made of fired clay that has been glazed to create a smooth interior surface. This type of pipe is not as strong as other types of plumbing pipes, but it is typically less expensive. Clay pipe was once a popular choice for plumbing applications, but it is not as commonly used today. They can be susceptible to breakage and are also not as durable as other types of pipes.
Concrete pipe is another type of pipe that is commonly used in plumbing. It is made out of concrete, which is a material that is both strong and durable. Concrete pipe is often used for sewer lines and other types of drainage systems. It is also commonly used for irrigation systems. Concrete pipe is available in a variety of sizes, and it can be customized to meet the needs of any project.
Polypropylene (PP) Pipe
Polypropylene pipes are plastic pipes found in plumbing systems. They are flexible, durable, and resistant to alkalis and acids. Due to their sensitivity to heat, Polypropylene pipes can only be used for wastewater under 212 degrees Fahrenheit (100 degrees Celsius), which is sufficient for almost all non-industrial applications. These pipes can also be affected by direct sunlight. Polypropylene pipes cannot be solvent welded.
Polyethylene (PE) Pipe
Polyethylene pipes are flexible plastic pipes that are used for irrigation systems and cold water supply pipes. They are shock-resistant and have little issue with freezing weather conditions. Polyethylene is either blue or black in color, with blue indicating the pipe is medium-density, and black indicating the pipe is high-density. The temperature rating for PE is much less than PP and is rated for 140 degrees Fahrenheit (60 degrees Celsius) which limits the usage of this pipe to cold water only.
Polybutylene (PB-1) Pipe
Polybutylene pipes are plastic pipes that are designed for pressurized plumbing systems. They were first developed in the 1980s, and are flexible and non-corrosive. They have high temperature and pressure resistance and have a low noise transmission. Something to note is that these pipes are micro-porous, meaning air can go through the walls of the pipe.
Which type of pipe is best for house plumbing?
There is no one size fits all answer to this question as the best type of pipe for your home plumbing system will depend on a variety of factors. However, some of the most popular types of pipes used in residential applications include PVC, PEX, and copper. Each type has its own advantages and disadvantages, so it is important to consider your budget, local climate conditions, and any other specific requirements when making a decision.
In new construction, consult with your engineer of record to find the best solution for your house. For example, PVC pipes are typically less expensive than copper or PEX and are easier to install, while copper is more durable and may be the best choice for cold climates.
What type of pipe is used for main water lines?
In the United States, there are two types of pipe that are commonly used for main water lines: copper and galvanized steel. PVC is normally used for drainage, and PEX is more common for domestic water. Another note on PEX is that is inexpensive and easy to work with, but it can leach certain chemicals into the water supply if installed improperly. Ultimately, the type of pipe that is used for main water lines depends on the needs and budget of the homeowner.
What are the safest water pipes?
When it comes to plumbing, there are a variety of materials that can be used for water pipes. However, not all materials are equally safe. Copper pipes are considered to be one of the safest options, as they are not susceptible to corrosion or leaching.
How to choose the right plumbing pipe?
Some considerations to keep in mind when selecting a pipe for your plumbing system include the material from which it is made, the size of the pipe, and how it will be installed. Factors such as cost and ease of use may also play a role in your decision. Ultimately, understanding what each pipe offers will help you make an informed choice that meets your needs and fits within your budget. It may be helpful to speak to a licensed engineer or an experienced contractor to get expert advice on which type of pipe is best suited for your project.