Uponor PP-RCT is a polypropylene pipe that is a lightweight, durable product that resists corrosion, rust and scale buildup, making it ideal for mechanical HVAC piping applications, such as hydronic heating, hot water and chilled water, the company points out. It provides elevated temperature and pressure ratings compared to PP-R piping products, allowing for use in a wider range of hydronic distribution applications, Uponor adds.