May 9, 2023

So, What is PP-RCT? 

by Ryan Swindell

PP-RCT is the fourth and most-recent generation of polypropylene resin that has higher pressure and temperature resistance than the previous generations of PP-R resins. PP-RCT is being adopted as a polymer alternative to more traditional metallic systems due to the many benefits it provides over metals. 

Using PP-RCT as an alternative to metallics offers several benefits to commercial plumbing and mechanical piping installers. For one, it weighs up to 80% less than steel and requires no open flame to make a connection. This provides a much safer environment for installers. 

Additionally, with metal piping, it can take years of apprenticeship to become a skilled welder. On the flip side, PP-RCT is relatively quick to learn and master. When pairing a trained and experienced PP-RCT fusion technician with the appropriate tooling setup, installation time can drastically improve job-site productivity. 


And finally, because metals are a commodity product, it makes pricing unpredictable. This can prove challenging when trying to accurately bid a job. PP-RCT pricing, on the other hand, remains stable. So, it’s easy to bid a job with confidence knowing the materials costs. 

Uponor offers PP-RCT in pipe sizes from ½" to 12" for mechanical applications in SDR 7.4, SDR 9, SDR 11, and SDR 17.6. For domestic hot and cold water applications, Uponor offers PP-RCT in ½" to 8" diameters in SDRs 7.4, 9, and 11. The fiber layer in the mechanical and hot potable pipe reduces thermal expansion, allowing it to perform at the higher temperatures and pressures of metallic systems. 

For many applications, designing a hybrid PEX and PP-RCT piping system is ideal with the transition to PEX at 2" (similar to the transition between steel and copper). Uponor offers PP-RCT with a 10-year warranty and PEX with a 25-year warranty, providing building owners, engineers, and contractors added confidence with the benefit of one warranty holder.