August 21, 2024 – Polypropylene (PP) pipes, a common thermoplastic piping material, are widely used due to their lightweight, high strength, corrosion resistance, and high-temperature tolerance. In this article, we will delve into the various types of PP pipes and their distinct characteristics.
PP pipes are primarily classified into several types: PP-H, PP-B, PP-R, PP-RCT, and FRPP. Each type differs in terms of raw materials, properties, and intended applications.
PP-H, or homopolymer polypropylene, is polymerized from propylene monomers, resulting in a uniform molecular structure. This uniformity confers high strength, excellent chemical resistance, and good high-temperature tolerance. However, its low-temperature impact resistance is relatively poor. With a long-term usage temperature range of approximately 0-100℃, PP-H pipes are ideal for transporting high-temperature liquids and chemicals, such as in chemical plants and industrial piping systems.
PP-B, or block copolymer polypropylene, is copolymerized from propylene and ethylene monomers. The addition of ethylene reduces the crystallinity of the material, making PP-B pipes more flexible and ductile than PP-H pipes. This improvement also enhances low-temperature impact performance. With a long-term operating temperature range of approximately -20℃-60℃, PP-B pipes are primarily used for transporting cold and warm water, especially in building water supply and drainage systems.
PP-R, or random copolymer polypropylene, is made from raw materials where ethylene monomers are randomly distributed within the propylene chain. This structure gives PP-R pipes a balance of rigidity, flexibility, and low-temperature resistance. With a long-term operating temperature range of -10℃-65℃, these pipes are commonly used in residential and commercial buildings for cold and hot water piping, underfloor heating systems, and drinking water transportation.
PP-RCT, a high-temperature resistant β-crystalline polypropylene pipe, enhances high-temperature performance, improves low-temperature brittleness, and strengthens creep resistance through optimized crystallization. This extends the service life of the pipe. With a long-term operating temperature range of -20℃-95℃, PP-RCT pipes are widely used in high-temperature hot water piping systems and demanding industrial piping systems.
FRPP, or fiberglass reinforced polypropylene, enhances performance by adding alkali-free glass fiber masterbatch to polypropylene. This significantly improves mechanical properties, high-temperature resistance, and corrosion resistance, making it resistant to most acids, alkalis, salts, and organic solvents. With a long-term operating temperature range of 0℃-90℃, FRPP pipes are primarily used in highly corrosive and high-temperature applications such as chemical production, electroplating, and environmental protection.
Additionally, PP pipes offer various connection methods, including hot melt connection, electric melt connection, threaded connection, and flange connection, allowing for flexible installation based on specific application scenarios.
Overall, PP pipes exhibit excellent chemical resistance, wear resistance, lightweight and easy installation, good thermal stability, and certain impact resistance and aging resistance. These characteristics make PP pipes widely used in various fields such as building water supply and drainage, cold and hot water supply, chemical industry, agricultural irrigation, and industrial applications. Furthermore, relevant national standards such as GB/T 18742.1-2017 and GB/T 35451.1-2017 provide guidelines for the production and application of PP pipes.