The main difference between CPVC and PVC is the range of temperatures each is capable of withstanding. CPVC can handle temperatures up to 200° Fahrenheit, while PVC peaks at 140° Fahrenheit. Above those temperatures, both CPVC and PVC will begin to soften, increasing the risk of joints and pipes failing, and therefore, failing of the plumbing system.
The primers, solvent cements, and bonding agents are different for PVC and CPVC due to the differences in the material's chemical composition. For example, CPVC solvent cements must meet ASTM F493 specifications, and PVC solvent cements must meet ASTM D2564 specifications. Because of this, CPVC and PVC pipes and fittings, along with their solvents and bonding agents, should not be used interchangeably. In addition to meeting ASTM specifications, there are different solvent cements required based on the pipe’s size and intended application, so check the product containers to be sure you’re using the correct agent for the correct application.
PVC comes in nominal pipe sizes only, while CPVC is available in both nominal pipe sizes and copper tube sizes. CPVC has greater flexibility than PVC, and requires support at three foot intervals to maintain its position.
| Characteristic | Schedule 40 PVC | Schedule 80 PVC | Schedule 40 CPVC | Schedule 80 CPVC |
|---|---|---|---|---|
| Cost | $0.40 / ft. | $0.52 / ft | $2.50 / ft | $3.02 / ft |
| Color | white, dark grey | white, dark grey | light grey, off-white, yellow | light grey, off-white, yellow |
| End Shape | plain, bell | plain, bell | plain | plain |
| Working Max Pressure | 450 PSI | 630 PSI | 450 PSI | 630 PSI |
| Tensile Strength | 7500 PSI | 7500 PSI | 8200 PSI | 8200 PSI |
| Standard Length | 10', 20' | 10', 20' | 10' | 10' |
| Sizing | NPS | NPS | NPS, CTS | NPS, CTS |
| Max Temp | 140° F | 140° F | 200° F | 200° F |
| Min Temp | 33° F | 33° F | 33° F | 33° F |
Common uses for both CPVC and PVC
Commercial
- Housing underground wires
- Plumbing, drainage, and sewage infrastructure
- Drinking and process water delivery and distribution
- HVAC, fume, exhaust and ventilation duct
- Agriculture, livestock and farm irrigation systems
Residential
- Home irrigation and sprinkler systems
- Home ventilation duct
- Drinking water distribution
- Residential plumbing, drainage, sewage infrastructure
Recreational
- Makeshift tents and shaded seated areas
- Frames for greenhouses, carports, and raised garden beds
- DIY projects and crafts
For more on what PVC and PVC pipe is used for, read our resource article What is PVC Used For.
Characteristics and Properties
CPVC and PVC Visual Similarities and Differences
- PVC pipes are white or dark gray in color.
- CPVC is off-white, light gray, or yellow in color.
- Both pipe types have technical specifications printed on the side for easy verification.
- Both pipe types are available in plain end and bell end.
- Both come in Schedule 40 and Schedule 80 thickness.
- Schedule 40 PVC also comes in Class 125 fittings.
- PVC is available in 10 ft and 20 ft lengths.
- CPVC is available in 10 ft and 20 ft lengths.
- Certain diameters of PVC pipe and furniture PVC pipe are now available in 5 ft sections.
CPVC and PVC Properties
- Both resist corrosion and degradation from chemicals classified as an acid, alkali, or inorganic material.
- PVC maximum functional temperature is 140° Fahrenheit.
- CPVC maximum functional temperature is 200° Fahrenheit.
- The extra chlorine in CPVC increases chemical strength and helps prevent bacteria / biofilm formation within the pipes.
- Both are impact-resistant and durable.
- Both are safe for use with potable water when ANSI / NSF 61 certified.
Special Considerations
- When PVC or CPVC is heated, melted, or hot-cut, fumes that are toxic (dioxin and hydrochloride) are emitted.
- When working with PVC or CPVC, work in a well-ventilated area with proper safety apparel, including gloves, goggles and a respirator if available.
- For solvent welding, each material requires a primer and solvent cement (pipe glue) designed specifically to be used with PVC or CPVC. The type of solvent cement may vary based on the pipe's intended application.
- PVC is less expensive than CPVC, and both materials are cheaper than copper, iron or stainless steel pipes.
- PVC pipes are sized by the nominal pipe size (NPS) sizing standard (NPS references the pipe interior diameter).
- CVPC pipes are sized by the nominal pipe size (NPS) and copper tube size (CTS) sizing standard (CTS references the pipe outside diameter).
What is PVC pipe?
Commonly used to create plumbing pipes and fittings, polyvinyl chloride is a man-made plastic with added stabilizers that prevent oxidation and degradation. As seen in the image below, PVC’s chemical composition is made of two carbon atoms linked together with a perimeter of three hydrogen atoms and one chlorine atom, all attached by single bonds. This individual molecule unit (a monomer) is then further linked together with other molecules of the exact same structure to form chains (a polymer) that are extruded as PVC to form PVC products like pipe.
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Polyvinyl Chloride Molecule
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Polyvinyl Chloride Resin Code
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Initially introduced to the US sewage, drainage, and water market in the 1950’s, there are now more than two million miles of PVC pipe in service today. PVC is engineered to resist oxidation and degradation, making PVC products and pipework highly durable. When properly installed, PVC pipes are capable of a lifespan of 50 years or longer. Reasons PVC may fail include: poorly glued joints or tree roots displacing underground lines or burrowing their way into the pipe itself.
For more on what is PVC, the characteristics and properties of the plastic, read our resource article What is PVC | What is uPVC.
Physical Characteristics of PVC Pipe
The color of PVC pipe is traditionally white or dark gray, with a technical description of the pipe printed on the side. PVC is available in both rigid form (also known as uPVC: commonly used in construction and piping applications) and flexible form (plasticized PVC, known simply as PVC: found in electrical cable insulation). Both forms of PVC are safe to touch and handle, and do not leach chemicals when used as the manufacturer intended.
PVC Pipe Installation
PVC can be cut with saws and glued to other PVC pipes and fittings without the need for heat or flame, such as is necessary to weld copper or iron pipes. For some applications you may determine a need to heat the pipe to make it more pliable -- be sure to wear protective gloves, respirator, and safety glasses to prevent burns and exposure to fumes. When PVC discolors under heat, it is burning and all work should cease immediately and be modified to prevent excessive toxins from becoming airborne.
Limitations of PVC Pipe
PVC has a peak temperature threshold of 140° Fahrenheit. For applications requiring temperatures above that, CPVC (chlorinated polyvinyl chloride) is recommended. CPVC offers some benefits over PVC, but at a slightly higher price point.
PVC Pipe Uses
Approved PVC pipe uses depend on the application and local building codes. While both PVC and CPVC are suitable for water, gas, and drainage systems, many plumbers strongly recommend CPVC for hot water lines and PVC for cold water lines. Since PVC has a maximum temperature threshold of 140° Fahrenheit, its use isn’t recommended in applications where the temperature of the fluids it will carry or its ambient environment will regularly approach, remain constant at or go above that peak temperature. CPVC would be recommended in these situations since its peak temperature threshold is 200° Fahrenheit. You may be surprised to learn that household water temperatures are not supposed to go above 140° Fahrenheit:
- Per the Consumer Product Safety Commission, water heaters may be set to 140° Fahrenheit, but should deliver water at 120° Fahrenheit to prevent scalding and burns in showers.
- Dishwashers work best at temperatures at or below 140° degrees Fahrenheit.
- Per the National Spa and Pool Institute, hot tubs are now designed to heat up to a maximum of 104° Fahrenheit.
- Washing machine temperatures peak at 140° Fahrenheit.
What is CPVC pipe?
CPVC is a thermoplastic made by further chlorination of the polyvinyl chloride resin. This means its chemical composition is two carbon atoms bonded to each other with two hydrogen atoms and two chlorine atoms bonded to this double carbon unit. This molecule links with others to form polymer chains of CPVC. CPVC delivers superior resistance to degradation and provides a long service lifespan. In fact, the first piping systems using CPVC occurred in 1959 and are still working without a problem.
For more on what is CPVC, its characteristics, properties and common uses, read our resource article What is CPVC.
CPVC Pipe Physical Appearance
CPVC pipes are sized in two ways -- nominal pipe size (NPS references the diameter of the interior hole of the pipe) and copper tube size (CTS references the outside diameter of the tube). Often, pipes using the NPS system are light gray, and pipes using CTS system are yellow. Both types of pipe will have their specifications printed on the side.
CPVC and PVC Similarities
It is safe to use CPVC in applications where PVC may be used. Both PVC and CPVC have been deemed safe for potable water transport, i.e. cooking, drinking, and bathing water, but only plumbing that has received ANSI / NSF 61 certification should be used. CPVC and PVC both offer significant chemical resistance and are largely resistant to degradation from acid, alkali, and most inorganic chemicals. However, both materials require UV stabilizers or underground installation to prevent deterioration from the sun.
CPVC and PVC are both a quieter, easier to install, and less expensive alternative to copper and iron pipes, especially in plumbing applications. Because they are thermoplastics, they have an inherent insulation that reduces condensation formation on the pipes and maintains both cold and hot water temperature better than copper pipes do.
They are available in the same lengths, with the same end shape options. Because their chemical composition contains a halogen -- the element chlorine -- their structure is stable and innately fire retardant. This stability also inhibits oxidation reactions, resulting in giving both PVC and CPVC a long, useful performance life. Each material can often be identified by pipe color and, if not, by reading the manufacturer printing located on the side of the pipe.
So which one do you choose?
PVC Pipe
Budget-friendly, temperatures under 140° Fahrenheit, most suitable for recreational applications, residential construction, DIY projects and cold water distribution. Looking for PVC pipe for sale or to compare prices?
CPVC Pipe
Superior resistance and performance, temperatures under 200° Fahrenheit, most suitable for commercial applications, chemical handling and hot water distribution. Looking for CPVC pipe for sale or to compare prices?
Other Resources
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