PVC water supply pipes are generally not recommended for hot water systems. Although PVC water supply pipes have the advantages of being light, pressure-resistant, corrosion-resistant, and easy to install, and are suitable for water pipes, building water supply, farmland irrigation, etc., their temperature resistance is relatively poor. In a high-temperature environment, PVC materials may deform or age, which will affect their service life and performance. Therefore, for hot water systems, especially those that need to withstand higher temperatures, it is usually recommended to use other pipes that are more resistant to high temperatures.
Why PVC pipes cannot be used for hot water supply
1. Poor heat resistance: PVC pipes have poor heat resistance. When the temperature is higher than 90 degrees, they begin to decompose slightly, releasing gas, which will cause harm to the human body after dissolving in water. The standard for PVC pipes stipulates that the use temperature should not be higher than 45 degrees Celsius. If the temperature exceeds this, the performance of the pipe will drop sharply. The higher the temperature, the easier it is to break. Therefore, it is not suitable as a hot water delivery pipe.
2. Decomposition at high temperatures will produce harmful substances: PVC pipes will decompose at high temperatures to produce gases such as hydrogen chloride, which will dissolve in water and cause harm to the human body. The national standard for PVC pipes stipulates that the use temperature should not exceed 45 degrees Celsius. If the temperature exceeds this, the performance of the pipe will decrease rapidly, so it is not suitable for transporting hot water.
3. Safety hazards exist: Since PVC pipes are not heat-resistant, they will age and deform after being heated. If PVC pipes are used to connect electric water heaters, they will not only fail to play a certain role but also pose certain safety hazards.
PVC pipe uses a temperature range
PVC water pipe is a kind of plastic pipe widely used in water supply and drainage systems, and its use temperature range is relatively wide. Under normal circumstances, PVC water pipe can be used normally in the temperature range of -10℃ to 40℃. In this temperature range, PVC water pipe has good heat resistance and cold resistance, which can ensure the stability and safety of the water pipe.
However, when the water temperature exceeds 40℃, the PVC water pipe may age, so when used in the hot water system, it should be ensured that the water temperature does not exceed 60℃ to ensure the service life of the water pipe. Similarly, when the ambient temperature is lower than -10℃, PVC water pipe may harden and affect the smooth flow of water, so when used in cold areas, antifreeze measures should be taken to ensure the smooth flow of water pipe.
Pipes suitable for hot water supply
Copper pipes, stainless steel pipes, or plastic pipes specially designed for hot water systems. When choosing pipes, in addition to considering their temperature resistance, it is also necessary to make comprehensive considerations based on specific application scenarios and needs. For example, although copper and stainless steel pipes are resistant to high temperatures, they are relatively expensive; some plastic pipes specifically used for hot water systems may have better cost-effectiveness. For example, PP-R pipes, also known as type III polypropylene pipes, are a new type of plastic pipe material that has good impact resistance and long-term creep performance. This material can be used for a long time under temperature conditions below 70°C, meeting the requirements of building hot water supply pipes. The advantages of PP-R pipes include moderate price, stable performance, heat resistance and insulation, corrosion resistance, smooth inner wall without scaling, safe and reliable pipe system, and impermeability. In addition, PP-R pipes can be used for up to 50 years, so they are widely regarded as high-quality pipe materials suitable for hot water supply. Although its construction technology requirements are high and special tools and professionals are required to ensure system safety, its advantages far exceed the limitations of its construction requirements, making PP-R pipes the first choice for hot water supply pipes.
