CPVC Or PVC: Which Is Better?
Polyvinyl chloride (PVC) is a multipurpose and well-known thermoplastic material that is commonly used in residential and business plumbing operations as fittings and piping. Another material in the very same family as PVC is CPVC (chlorinated polyvinyl chloride). Both are popular, but which is better?
Whenever it concerns temperature and pressure resistance, CPVC outperforms PVC. CPVC is comparable to PVC in terms of accessible product kinds and names. Still, it has better pressure and heat resistance, allowing it to be used in increasingly demanding commercial processes. CPVC is also more fireproof than PVC, making it more ideal for residential homes as well.
The molecular constitution of the materials causes variances in temperature and heat resistance. To establish which is better, we look at the distinctions between PVC and CPVC.
Which Should You Use: PVC or CPVC?
If you need a material that can withstand chemicals, pressure, and heat, CPVC is the way to go. However, the type you should utilize is determined by the problem you want to tackle.
You should be aware that the majority of the essential features of PVC and CPVC are the same in both materials. CPVC outperforms PVC due to molecular differences, particularly in terms of pressure and temperature resistance.
Fire Performance
All thermoplastics, such as polyethylene and polypropylene, have a terrible history when it comes to fireproofing. Not all thermoplastics, however, are prone to melting and burning.
Industrial CPVC is designed to produce less smoke and be less explosive. Some tests will assess the following characteristics of your material.
The flash ignition temperature is the lowest temperature where an external flame could burn any combustible gas. PVC has a flashing ignition temperature of 750°F (399°C), while CPVC has a flashing ignition temperature of 900°F (482°C).
The Limiting Oxygen Index (LOI) is the amount of oxygen necessary to keep a flame going in the surrounding air. Corzan CPVC has a LOI of 60, while PVC has a LOI of 45. For your information, the atmosphere contains 21% oxygen.
Chemical Resistance
Throughout the last ten years, thermoplastics have gained in prominence as replacements for traditional metals. For example, the PVC industry, which was worth $57 billion in 2015, is expected to grow to $79 billion by the end of 2021.
CPVC and PVC are impervious to bases, salts, many acids, and aliphatic hydrocarbons, unlike metals, which can be impacted by scaling, pitting, and corrosion. This has been shown to prolong the life of specific materials for decades or even years.
Chemical resistance is thus a distinct benefit of both PVC and CPVC. However, because of the variation in chlorine content, both CPVC and PVC have distinct purposes, with each having a unique benefit.
PVC is inferior to CPVC when considering the high sulfuric acid content and the fact that both materials are appropriately made.
When ammonia comes into touch with chlorine, though, it becomes highly reactive. Because CPVC contains a considerable amount of ammonia, PVC performs better in situations where ammonia is present.
You can use a chemical compatibility chart to help you determine whether or not to utilize CPVC. You can also seek assistance from a professional.
Pressure Resistance
At 73°F (22.8°C), PVC and CPVC are intended to withstand the same pressure. However, CPVC maintains the temperature when the temperature rises stronger than PVC.
Take, for example, the pressure rating for a 10 in. PVC and CPVC piping should be installed at a temperature of 130°F (54.4°C). Note that each material’s rated pressure is 230 psi at 73°F (22.8°C).
PVC has a derating factor of 0.31 at temps of 130°F (54.4°C). As a result, it has a pressure of 71.3 psi (230 psi x 0.31 = 71.3 psi).
CPVC has an incremental loss factor of 0.57 at ranges of 130°F (54.4°C). As a result, it has a pressure of 131.1 psi (230 psi x 0.57 = 131.1 psi).
Even if your PVC material performs effectively at 130°F (54.4°C), it will bear less pressure as the temperature rises.
Temperature Resistance
The glass transition temperature (Tg) of CPVC rises as the chlorine content increases. The transition point is the temperature at which a polymer transforms from a glassy, hard solid to a rubbery, soft substance, losing its structural integrity.
When compared to PVC, CPVC has a higher temperature resistance. The optimal service temperature of PVC, for example, is 140°F (60°C). CPVC, on the other hand, has a maximum service temperature of 200 degrees Fahrenheit (93.3 degrees Celsius). Nevertheless, you should always double-check each material’s operational capability with the manufacturer.
So over the maximum service temperature of PVC, CPVC performs admirably. It also has a higher temperature resistance, allowing it to work well at temperatures within PVC’s operating range.
At ranges below 140°F (60°C), for example, CPVC still outperforms PVC in terms of tensile and impact strength.
Can You Use PVC Instead of CPVC?
Because they have some commonalities in application, it is safe to use PVC instead of CPVC in some cases. Here are a few of them:
- Both materials, for example, are safe in portable water transit applications. This includes everything, such as showering, drinking, and cooking. However, you should only use either on plumbing that has been certified by ANSI/NSF 61.
- PVC and CPVC are both chemically robust and offer substantial resistance to alkali, acid, and also most inorganic compounds. Both materials must be installed underground to prevent deterioration from the sun, and UV stabilizers must be used.
- PVC and CPVC pipes are easier to set up, quieter, and less expensive than iron and copper pipes, especially for plumbing purposes. Because they are thermoplastics, they have built-in insulation that prevents condensation from forming on lines. When compared to copper pipes, this allows them to retain hot and cold water temperatures more effectively.
- Both items are provided in the very same end form and length options. They have an inbuilt fire retardant and stable structure due to the presence of chlorine, a halogen in their chemical composition.
- Because of the material’s stability, oxidation is prevented, resulting in a long service life for both CPVC and PVC. You may identify each material by reading the manufacturer’s printing on the pipe’s side or looking at the color of the pipe.
Can You Glue PVC and CPVC Together?
There are a few instances where PVC and CPVC materials can be joined together. A coupler, on the other hand, cannot be used to connect them.
- Prepare your CPVC to PVC connector pieces. Using a CPVC primer, prepare the first 2-inches of your external CPVC and PVC surfaces. The inside of the PVC to the CPVC adapter can then be primed. The prepping brush is usually attached to the primer can’s lid.
- Apply a light application of CPVC adhesive to the prepped portion of the pipe and let it dry. Do the same with the PVC-to-CPVC adapter’s side.
- Slip the glued side of your adaptor onto the glued end of the CPVC pipe. After that, keep the adapter on that side for around 30 seconds to ensure that the components are adequately bonded.
- The PVC side of your PVC-to CPVC adaptor can be glued. Do the same thing with your PVC pipe’s primed end.
- Link it all together. To complete the joining process, link the glued opening adapter side to the glued PVC pipe side and keep them in place for around 30 seconds.
Why Is CPVC Plumbing Recommended Over PVC Piping In Homes?
We advocate using CPVC instead of PVC in your applications because of its chemical composition, which makes it suitable for any use.
And it’s not by luck that CPVC is more widely used than PVC. Let’s have a look at why CPVC is preferred over PVC:
CPVC Has Higher Pressure Resistance
Additional reasons why CPVC is used in homes is because it is more resistant to pressure than PVC. PVC can resist a pressure of 71.3 psi at 130°F (54.4°C), but CPVC can resist a pressure of 131.1 psi at the very same conditions. This means that CPVC can be used in high-pressure plumbing applications.
CPVC Includes a Higher Maximum Service Temperature
In comparison to PVC, CPVC has a stronger temperature resistance. The glass transition temperature (Tg) of CPVC rises as the chlorine content increases.
As previously stated, the temperature at which a polymer transforms from a glassy, hard solid to a rubbery, soft substance causes it to lose structural integrity.
For example, while PVC has a maximum service temperature of 140 degrees Fahrenheit (60 degrees Celsius), CPVC has a maximum service temperature of 200 degrees Fahrenheit (93.3 degrees Celsius). As a result, CPVC has a higher temperature resistance.
CPVC Allows For A Longer Lifespan
All PVC and CPVC are immune to bases, salts, most acids, and aliphatic hydrocarbons, as we’ve shown. This indicates that, in comparison to other common materials, the materials will have a longer lifespan.
CPVC, on the other hand, offers better chemical resistance than PVC. As a result, we recommend that you choose CPVC for high-response jobs.
CPVC Includes a Higher Limiting Oxygen index
In addition, CPVC has a stronger limiting oxygen index of 60, which is greater than PVC’s limiting oxygen index of 45.
Even though CPVC has higher fire, thermal, pressure, and chemical resistance, you must never skip using PVC when it is appropriate.
CPVC Has Less Chance of Melting
CPVC has a stronger fire resistance than PVC, in addition to being more resistant to pressure, chemicals, and temperature. It isn’t prone to liquefying or burning in most circumstances.
Smoke generation and flammability are limited with industrial CPVC. PVC has a flashing ignition temperature of 750°F (399°C), while CPVC has a temperature of 900°F (482°C).
Heather is a passionate writer who loves anything DIY. Growing up, she learned everything from home repairs to design, and wants to share her tips with you. When she's not writing, she's usually hiking or searching for her next DIY project.
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