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Introduction to PP-R Pipes I. What are PP-R pipes? PP-R pipes, also known as type III polypropylene pipes, are made by extruding randomly copolymerized polypropylene to form pipes, and by injection molding to create pipe fittings. It is a new type of plastic piping product developed and put into use in Europe in the early 1990s. PP-R is a new generation of piping material that emerged in the late 1980s, created through a gas-phase copolymerization process in which about 5% of PE is randomly and uniformly polymerized within the PP molecular chains (random copolymerization). It has good impact resistance and long-term creep resistance. II. What is the relationship between PP-R and PP-C? In the past, PP-C pipes and fittings appeared on the domestic market, and their installation method was the same as that of PP-R pipes. Many people are confused about the difference between PP-R and PP-C, which has led to numerous misunderstandings and confusion. According to international standards, polypropylene hot and cold water pipes are classified into PP-H, PP-B, and PP-R types; there is no PP-C type. The PP-C pipes available on the market are actually PP-B pipes, whose raw material is a special material designed for block copolymerized polypropylene pipes. PP-B pipes are a type of hot and cold water pipe; they are relatively inexpensive, but their heat resistance and pressure resistance are significantly inferior to those of PP-R pipes. For example: Using condition classification 2, with a design pressure of 0.6 MPa and a pipe diameter of 25 mm; the wall thickness of PP-R pipes is 3.5 mm, while that of PP-B (PP-C) pipes is 5.1 mm ； The design pressure is 0.8 MPa for dn25mm pipes; the wall thickness of PP-R pipes is 4.2 mm, while PP-B (PP-C) cannot be used in this context. Because the required wall thickness is too thick. PP-C pipes available on the market that have the same structural dimensions as PP-R pipes are designed for much lower operating conditions; they cannot be used interchangeably with PP-R pipes, and PP-C pipes must not be used in place of PP-R pipes once the appropriate operating conditions have been determined. Condition 2 indicates a design temperature of 70°C for hot water supply. III. What are the characteristics of PP-R pipes? In addition to the common advantages of plastic pipes such as light weight, corrosion resistance, no scaling, and long service life, PP-R pipes also have the following key features: 1. Non-toxic and hygienic. The raw material molecules of PP-R consist only of carbon and hydrogen; there are no harmful or toxic elements present, making it safe and reliable. It is used not only for hot and cold water pipes but also in systems for pure drinking water. 2. Heat preservation and energy saving. The thermal conductivity of PP-R pipes is 0.21 W/m·K, which is only 1/200 that of steel pipes. 3. Good heat resistance. The Vicat softening point of PP-R pipes is 131.5°C. The maximum operating temperature can reach 95°C, meeting the requirements for hot water systems as specified in building plumbing codes. 4. Long service life. Under operating temperatures of 70°C and an operating pressure (P.N) of 1.0 MPa, PP-R pipes can have a service life of over 50 years ； At room temperature (20°C), its service life can exceed 100 years. 5. Easy to install with reliable connections. PP-R has good welding properties; pipes and fittings can be connected by heat fusion or electrofusion. It is easy to install, the joints are reliable, and the strength of the connection areas is greater than that of the pipes themselves. 6. Materials can be recycled. PP-R waste is cleaned and crushed before being reused in the production of pipes and fittings. Recycled material: The usage amount should not exceed 10% of the total amount, as it does not affect product quality. IV. What are the main uses of PP-R pipes? 1. Hot and cold water systems in buildings, including central heating systems ； 2. Heating systems in buildings, including floor, wall panel, and radiant heating systems ； 3. Purified water supply system for direct drinking ； 4. Central (centralized) air conditioning system ； 5. Industrial pipeline systems for transporting or discharging chemical media, etc. Last edited by kingberg on 2009-2-2 13:21 in this post.]