Using the Right Piping Material for Your Plumbing Application
Tackling a plumbing project can be overwhelming, especially when you start to shop for piping and realize all of the different options available for you. Do you want PVC, galvanized metal, or flexible PEX tubing? Here are some details about the most popular types of plumbing piping and what they are best used for that might make your decision a little easier.
By far the most commonly used pipe in residential homes, polyvinyl chloride (PVC) pipe is the white piping commonly used in plumbing applications. Affordable and versatile with a number of different fittings and sizes available, PVC is great for most warm and cold water applications.
PVC works well for home plumbing piping needs because it does not rust or corrode over time. This means it will not need to be replaced until it is actually damaged and starts leaking. It is also easy to work with, as it requires no welding or metalwork, and is an inexpensive option for your home. PVC is quite strong and durable and does not bend under pressure, making it the piping solution of choice for high-pressure applications.
The main drawback to PVC pipe is the fact that it cannot be used with hot water applications. When exposed to hot water, PVC will warp. This means it cannot be used to deliver hot water to sinks, tubs and washing machines. It also may degrade when exposed to UV light for an extended period of time, and this includes the UV rays from the sun, so it is best suited for indoor applications or underground pluming.
PVC comes in two sizes, called “schedules.” Schedule 40 is the typically used PVC type. Schedule 80 has a slightly thicker wall. ANSI nominal pipe size table specifies the outside diameters of all schedules for a given pipe size to be equal and the inside diameter will vary according to wall thickness. Schedule 80 is slightly stronger than Schedule 40.
Unfortunately, most PVC is not rated for use for drinking water, not due to a high risk of toxicity, but due to the fact that it can degrade with high temperatures, UV light exposure and extremely high pressures. Any degradation can damage the water supply and make it unsafe for drinking water.
Typically, you will use PVC for:
- Sink drain lines
- Toilet drain lines
- Bathtub drain lines
- Vent stacks
- Main water supply line running to the home
- High-pressure applications
Chlorinated polyvinyl chloride pipes (CPVC) are made from PVC that has extra chlorine added to the material. It carries all of the benefits of PVC with added durability. CPVC will not degrade with hot water exposure and is safe for drinking water. It is slightly more expensive than PVC, however, and will split if allowed to freeze.
CPVC can be used in most applications where copper piping is used, but it is considered a better option for a number of reasons. First, the interior of CPVC pipe is smooth, which means it has little water noise when compared to copper plumbing systems, including little to no problems with “water hammer.” Second, it is well insulated to prevent energy loss in hot or cold applications. CPVC is also more flexible than metal tubing, providing a bit more versatility. Finally, it is extremely fire resistant.
CPVC is typically used for those applications where PVC properties are wanted, but PVC is not usable, including:
- Hot water delivery
- Drinking water delivery
- Hot water drains
- Waste and water disposal pipes
Since the 1960s, copper piping has been the standard for most home plumbing applications. The long lifespan and durability of this piping makes it an excellent choice for many applications. It tolerates heat well and is extremely resistant to corrosion. Copper does not degrade with water and therefore is safe for use with drinking water.
However, copper has one major drawback, and that is the price. This is one of the most expensive piping materials, and is at a high risk of theft on jobsites or in vacant houses. In today’s homes, you will most often see copper piping used for:
- Hot and cold drinking water supply
- Refrigerant lines for HVAC systems
- Other applications that require a tight seal
- Underground service lines
PEX piping is considered by many to be one of the biggest innovations in the home plumbing industry of the modern era. PEX is an extremely flexible piping option that can literally be snaked through a home and bent around corners when needed. It requires no glue and holds up better in freezing conditions than CPVC because the materials can expand and contract.
PEX is typically connected using stab-in or compression fittings, which require a special tool to use. PEX can be spliced into existing pipe, including copper pipe, which makes it a great choice for additions and retrofits. PEX is durable enough for hot water applications, but it cannot be connected directly to the hot water heater. For hot water supply lines, it must be connected to an 18-inch section of copper or other hot-water-safe piping.
Because of its flexibility and durability, PEX pipe is great for:
- Retrofitting an older home
- Snaking through walls in a remodel
- Working in areas with low ventilation where glue is dangerous
Galvanized piping is steel or iron piping that has been coated with zinc to help prevent rust and corrosion. Galvanized metal is commonly used in construction, but pipes made from galvanized steel can be used in plumbing applications. This particular type of pipe is best used for water lines, as gas lines can cause the zinc to corrode and damage the pipe or block the entire system. Even in highly corrosive conditions, galvanized pipes can last up to 100 years.
Galvanized pipes are typically used in the following applications:
- Water supply lines
- Outdoor applications
- Underground applications
Finally, brass piping is an option for certain applications. Highly resistant to corrosion as well as damage from heat and water, brass is also a soft metal that allows the installer to create a tight seal. It has a heavier wall than copper but offers many of the same benefits, including safety in use with drinking water.
Lead is one potential problem with brass piping. Brass is an alloy, which means it is a mixture of metals, and many of the brass alloys contain lead. Lead cannot be allowed to leach into drinking water, so today’s plumbers choose brass that is lead-free.
Brass is an older option that was commonly used before the introduction of copper to the home plumbing market, but it is still relevant today. Some applications of brass piping include:
- Water supply lines
- Water removal drains and lines
- Some applications for gas lines, depending on local building code
As you can see, choosing the right piping material is not always easy. Before starting your plumbing job, make sure you do your research to ensure that the plumbing material you choose is the right fit. To purchase the piping and fittings you need at an excellent price, visit Commercial Industrial Supply today.
Amanda Hill is the Head of Marketing at Commercial Industrial Supply, a commercial / industrial supplier & distributor of pipe materials nationwide. Since 2009 CIS has pushed to bring the highest quality piping products to market.