May 15, 2024

The History and Evolution of the PP-RCT Piping Solution 

by Brock Johnson

PP-RCT, or Polypropylene Random Copolymer with Crystallinity and Temperature Resistance, is the newest generation of high-performance polypropylene resins. To understand the development and history of this piping system, we need to understand the first P: Polypropylene


What is polypropylene?

First created in 1954, polypropylene is a material that offers excellent qualities in terms of chemical resistance, heat resistance, and temperature resistance. It has been used extensively in the manufacturing of plastic bottles, in the medical and automotive industries, as well as many other common applications that require the container not to leach into the internal substance. Polypropylene has also been used worldwide in piping systems for plumbing, mechanical, and industrial applications for more than 30 years.

The next evolution: PP-R piping solutions

Originally, polypropylene was polymerized in either long or short molecular-chain formulas. While these are both excellent materials, the way the molecular chains all lined up in the same pattern created areas of reduced strength where the “seams” lined up. The development of PP-R in the 1970s was a huge leap forward in material quality. The “R” (standing for Random) means the material is made up of both long and short molecular chains scattered randomly through the material. This random pattern staggers the joints in the molecular bond and greatly increases the ability to withstand elevated temperatures and pressures. Plus, it makes the material more ductile and shatter resistant.

More progress creates PP-RCT

Introduced in the late 2010s, PP-RCT, or Polypropylene Random Copolymer with Crystallinity and Temperature Resistance, is the newest generation of high-performance polypropylene resins. The material is manufactured through a special process that modifies the crystalline structure, resulting in a material with greatly improved temperature and pressure resistance that will remain strong and intact throughout its service life for long-term, superior performance.

Uponor introduces PP-RCT to product offering

Challenges with PP-R were common in the industry. But when PP-RCT became available, Uponor recognized this game-changing piping solution. PP-RCT provides a more than 50 percent improvement in long-term strength compared to PP-R. This long-term strength improvement allows designers to achieve higher pressure ratings with the same wall thickness, or potentially down gauge to a thinner-wall pipe with better hydraulic capacity and lower cost.

Uponor PP-RCT mechanical and hot-potable pipe is made with a unique co-extruded fiber composite layer. The fiber layer is essentially the “meat” in a PP-RCT sandwich. This fiber layer brings many notable benefits to the product — most importantly, reduced linear expansion. This integrated expansion-control layer keeps expansion rates similar to metal piping systems. It also enables a greater hanger spacing distance due to the added strength the fiber layer provides.

Total polymer solution

Globally, PP-R and PP-RCT piping systems have been used for many applications, from geothermal to compressed air to food processing. Here in the United States, Uponor PP-RCT is a great solution for domestic hot and cold water, hydronic heating hot water, and chilled water applications, as well as distribution piping for radiant heating and cooling, snow and ice melting, turf conditioning, permafrost prevention (cold storage), and industrial applications.

Uponor is the only manufacturer that offers a complete polymer piping solution that has all the benefits of PEX-a for smaller-diameter pipes as well as PP-RCT for larger diameters. PP-RCT also works seamlessly with Uponor PEX-a systems.

Unmatched warranty and expertise

Uponor PP-RCT is backed by a strong, 25-year warranty on the pipe and fittings. Polypropylene piping systems have been manufactured and used for decades in Europe, and 10 years is the standard European warranty.

The robust Uponor PP-RCT and PEX-a product catalogs work hand-in-hand with Uponor Construction Services, a team of professional estimators, designers, modelers, and polymer piping experts, that provide estimation and design expertise for domestic and mechanical water systems to ensure optimized performance and efficiency. This solution ensures one manufacturer for the design, training, support, and warranty of the entire piping system.

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Discover the benefits and applications of Uponor PP-RCT as well as PEX-a piping systems for reliable, sustainable, and high-performing commercial projects.

Learn more about PP-RCT