Difference Between PVC and CPVC (With Table)

The abbreviated term PVC stands from ‘Polyvinyl Chloride’ and CPVC stands for ‘Chlorinated Polyvinyl Chloride’. PVC and CPVC are piping and fitting materials which are commonly used for the purpose of residential and commercial plumbing applications.They come from the same thermoplastic family. Molecular formula forms the basis for the difference between PVC and CPVC.

PVC vs CPVC

The difference between PVC and CPVC is that the handling temperature of PVC is 140 Fahrenheit and CPVC is 200 Fahrenheit. They become soft and have increased risk of failing above the handling temperature. PVC is less expensive than CPVC, and they are cheaper when compared to copper, iron, or stainless steel pipes.

PVC is a man-made plastic that is used in plumbing works and it helps in preventing oxidation and degradation. PVC’s chemical formula is composed of 2 carbon atoms linked together with 3 hydrogen atoms and one chlorine atom using single bonds. It is also used in electric cable insulation.

CPVC belongs to the same family of PVC. PVC infused with Chlorination of the Polivinyl Chloride resin is called CPVC. CPVC’s chemical formula is 2 carbon atoms linked to 2 hydrogen atoms and 2 chlorine atoms using double bonds. It has much superior resistance when compared to PVC.

Comparison Table Between PVC and CPVC

Parameters of ComparisonPVCCPVC
DefinitionIt is called Polivinyl Chloride used in plumbing applications with resistant to degradation.It is called Chlorinated Polivinyl Chloride used in plumbing and other electric wiring applications with superior resistance.
ColourPVC is white, dark grey in colour.CPVC is light grey, off-white, yellow in colour.
TemperatureTemperature of PVC ranges from minimum of 33 degree Fahrenheit to maximum of 140 degree Fahrenheit.Temperature of CPVC ranges from minimum of 33 degree Fahrenheit to maximum of 200 degree Fahrenheit.
FlexibilityPVC is less flexible when compared to CPVC.CPVC is more flexible when compared to PVC
SizePVC is available in nominal pipe sizes.CPVC is available in nominal pipe sizes and copper tube sizes.

What is PVC ?

PVC is a commonly used as replacement for metal piping, as metal piping are highly prone to corrosion, oxidation and degradation. It is one of the most widely used plastics in the world due to its low cost,durability and easy installation. PVC is available in plain, bell shape, and available in various other shapes too.

PVC has a lifespan of 50 years long when properly installed. Few reasons for failure of PVC are poorly attached joints, tree roots displacements causing damage to the pipes, temperature ranging above 140 degree fahrenheit. Various other factors also lead to the failure of PVC pipes such as heat resistance above its level

PVC is available in 2 types or variants, they are Schedule 40 PVC and Schedule 80 PVC. Both are same in all aspects except in their working maximum pressure which is 450 PSI and 630 PSI for Schedule 40 PVC and Schedule 80 PVC respectively. These variants are easily available at affordable costs.

PVC is commonly used for commercial, residential and recreational applications. There are over 2 million miles of PVC pipes in service till date. PVC can be attached using glues and cut using saws without heating or using flames. PVC are more pliable than any other pipes.

What is CPVC ?

CPVC is a kind of thermoplastic modified by making chlorination to it. Chlorination of PVC is called CPVC. This process ensures to provide long lifespan and durability. It has been labelled as being safe for potable water transport. It offers significant chemical resistance and from other inorganic chemicals.

CPVC’s installation process is easy and it is less expensive when compared to copper and iron pipes. They maintain the temperatures of both cold and hot water transporting through the pipes. They are stable and fire retardant. They are available is 2 variants as of PVC pipes.

CPVC are heat resistant and can withstand upto the specified maximum and minimum temperatures. they are highly durable and available is plain shape. CPVC are available is 2 types, Schedule 40 CPVC and Schedule 80 CPVC. Both the variants vary only in their working pressure and tensile strength which is of 8200 PSI.

CPVC are highly used for drinking water distribution, plumbing, drainage, sprinkler system, underground wiring applications, makeshift tents, shaded seated areas. CPVC are available in a minimum of 10 feet to 20 feet lengths. The extra chlorination process is done to prevent degradation and increase chemical resistance and formation of bacteria.

Main Differences Between PVC and CPVC

  1. CPVC is superior to PVC in terms of Chemical Resistance. CPVC can inert most of the acids, bases, as well as aliphatic hydrocarbons, when compared to PVC.
  2. CPVC due to the chlorination process done in it, it is prone to highly reactive with chemicals like ammonia, which doesn’t happen in the case of PVC.
  3. There is an adverse effect on the CPVC when glass transition temperature rises, due to chlorination, which is not in the case of PVC.
  4. When the temperature increases, CPVC maintains it and withstands it way better than PVC pipes. PVC due to non-chlorination, cannot withstand above certain level of specified degrees of temperature.
  5. CPVC is limited to flammability and smoke production, whereas PVC are more prone towards flammability.

Conclusion

PVC and CPVC are from the same family of thermoplastics. They are commonly used for general applications like plumbing, wiring and so on. Both PVC and CPVC are chemical resistance, temperature resistance and has various physical properties and withstanding level of temperatures.

CPVC varies from PVC in few aspects like the level of withstanding temperature, flammability and heat resistance. In such cases CPVC seems to be more preferable than PVC. PVC is prefered in places where chemicals like ammonia quick reactant to chlorination is in use.

Both PVC and CPVC are commonly prefered and used as a replacement for copper, iron, aluminium and stainless steel pipes. Installation of PVC and CPVC pipes are easier than other pipes, as other pipes are not resistant to corrosion, degradation. PVC and CPVC have long life spans.

References

  1. https://onepetro.org/NACECORR/proceedings-abstract/CORR03/All-CORR03/NACE-03606/114469
  2. https://www.sciencedirect.com/science/article/pii/0033065594870055
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