CPVC in Water Handing Applications and Wet Environments

Posted by TempRite® Engineered Materials EMEA Team on 06/02/2021

TempRite® Engineered Materials have been engineering Chlorinated Polyvinyl Chloride (CPVC) for safe water distribution since the early days of the polymer’s existence. The earliest installations of CPVC were plumbing pipes, many of which perform fault-free to this day.

This is thanks to CPVC’s inherently superior qualities in water distribution and aquatic environments:

  • Inherent heat resistance
  • Immunity to corrosion by chlorinated water
  • Resistance to chemical corrosion and leaching
  • Ability to reject attachment of microbial bacteria
  • Insulation properties
  • Hydrolysis resistance

As a result, many TempRite CPVC compounds meet NSF International Standards for potable water safety and they have received the Annex G certification, a difficult recognition for polymers to receive.

These are just some of the industrial applications that benefit from CPVC’s inherent properties:

  • Plumbing pipes
  • Wastewater treatment
  • Hospitality industry
  • Sports and leisure facilities
  • Domestic applications

Engineering CPVC for Water Distribution

CPVC’s ability to outperform other materials in water handling applications is an inevitable result of the chlorination process by which it is created.

The molecular structure of PVC vs CPVC. Grey atoms represent the carbon chain, blue atoms represent hydrogen and the purple atoms represent chlorine, which protects the carbon chain


When PVC becomes CPVC, additional chlorine atoms are added to the polymer’s molecular structure. This process must take place in a volatile environment in which high temperatures and UV are used, creating free radicals. Under these aggressive conditions, CPVC is strengthened by chlorine atoms, providing a tough layer of protection against corrosive influences.

The chlorine content of CPVC molecules can be scaled up or down, depending on the level of resistance required. However, due to its strong nature, the more chlorine is added, the harder it becomes to add more.

This is why CPVC is naturally immune to degradation in chlorinated environments, such as potable water. This presents a great number of manufacturing opportunities where a strong, resilient but lightweight material is required to treat or transport water safely.

The Hazards of Water Distribution

Distribution of water naturally poses several threats to the integrity of the material that has been employed to transfer it from one point to another. Both chemical and natural phenomena threaten the molecular integrity of most materials.


Potable water is treated with chlorine and hydrochloric acid to remove organic contaminants. While harmless in water consumption, it can cause chemical degradation in some pipe materials. CPVC is immune to the degrading effects of chlorine and hydrochloric acid, thanks to the high level of chlorine in its molecular structure.

Hydrolysis is also a threat to some polymers in aquatic environments. Hydrolysis occurs when the water itself reacts with a polymer to depolymerize it, breaking its structure down into smaller pieces. CPVC is inherently resistant to hydrolysis as well.

Microbial Contamination

CPVC also resists harmful influences from the natural world; one such phenomenon often present in water distribution is biofilm. This glue-like substance is created by bacteria in water that thrives on textured surfaces in aquatic environments.

Biofilm can rapidly multiply and grow, eventually releasing dangerous bacteria back into the water. If consumed excessively these bacteria can cause mild illnesses or life-threatening consequences, through e-coli, legionella or pseudomonas.

Amorphous polymers like CPVC form smooth, glossy surfaces when extruded or injection molded. The smooth, highly-chlorinated surface is difficult for bacteria to colonise. This also prevents the natural growth of scaling, which over time can accommodate biofilm.

Applications of CPVC in Water Distribution

Plumbing Pipes

In hot and cold water distribution, in addition to corrosion and bacteria resistance, CPVC provides energy and cost savings as well. . CPVC’s has low thermal conductivity, which provides natural insulation. Unlike metal pipes, heat conduction is restricted, creating an insulating effect that keeps hot water hot for longer. Less energy is therefore required to maintain desired temperatures. Extra insulation may be eliminated in some applications, providing additional cost and maintenance savings.

Wastewater Treatment

Highly corrosive and hazardous chemicals are used in the wastewater treatment process. As such CPVC is widely used in this application for its high performance in corrosive environments, as well as its resistance to microorganisms found in wastewater.

Hospitality Industry

Standards of hygiene and sanitation are under closer scrutiny than ever before, since the global COVID 19 pandemic. CPVC’s performance in water storage and distribution in the food and beverage industry stands up to these stringent standards, where food processing often requires highly corrosive cleaning agents.

Sports and Leisure Facilities

CPVC is a natural choice for highly chlorinated water distribution in the sport and leisure industry. Communal areas requiring deep cleaning, especially in light of COVID 19, benefit from clean, robust surfaces that do not degrade. They also maintain their aesthetic throughout their service life, making CPVC ideal for extrusion of panelling for cubicles and partitions.

Domestic Applications

In kitchens and bathrooms, CPVC water pipes deliver cleaner water to homes through tough resistance to corrosion and contamination. Fenestration applications include glazing beads and profiles for windows and doors. Here CPVC is valued for its low coefficient of thermal expansion as well as its resistance to the corrosive effects of moisture and oxygen in the air.

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