The deterioration of pipes due to corrosion must always be considered when designing piping systems. This is because corrosion over time is one of the main factors causing metal pipes to deteriorate. CPVC pipes, on the other hand, have a significant advantage in that corrosion does not occur. This section introduces the mechanisms of corrosion and the characteristics of CPVC.

Problems of corrosion in piping systems

Corrosion or rust, is a direct factor in reducing the life of pipework. If left unchecked, corrosion can puncture pipes, reduce their mechanical strength and cause them to break on impact, or impede their ability to carry water due to scale* build-up. Damage to pipes can lead to water disconnection in hot/cold water supply pipes and fittings applications and to increased damage in the event of fire in fire sprinkler pipes and fittings applications. In addition, regular cleaning and periodic replacement of pipes is required to prevent deterioration due to corrosion, leading to higher maintenance costs.

*Scale: A substance dissolved in the liquid flowing in the pipes that precipitates and adheres to the inside of the pipes. It is a type of water stain.

Superiority of CPVC pipes

Comparison of cross-sections of metal and CPVC (chlorinated polyvinyl chloride resin) pipes that had been in service for 50 years showed that the metal pipes were significantly corroded with scale deposits inside. If left unchecked, the metallic components of the scale will leak out and worsen water quality. On the other hand, the CPVC pipes show almost no corrosion in cross-section. The comparison results show that CPVC is superior to metal pipes in terms of water safety and durability.
In terms of cost, CPVC is also superior in that it requires almost no internal cleaning. Metal piping requires periodic cleaning using chemicals to remove scale, which not only incurs a certain cost, but also has a significant impact on users when used for hot/cold water supply pipes and fittings. With CPVC pipes, such maintenance can be kept to a minimum.

The Sekisui Chemical Group offers the CPVC compound product “Durasutream” to moulding manufacturers as a raw material for CPVC pipes. Please feel free to contact us for more information.