Disadvantages of plastic pipes sensitivity to UV; inability to use the flush gasket compression fittings; the difference between linear expansion coefficients for PEX and aluminum foil, which can cause damage to the construction of the pipe. Comparative analysis properties of different types of plastic pipes is that the most heat-resistant metal and plastic are the pipes, PEX and polypropylene pipes. Less heat-resistant pipes are PVC and polyethylene pipes. This property allows the use of plastic pipes polypropylene pipes, PEX and composite tubes for hot water and heating. According to the degree of linear thermal expansion of plastic pipe can be divided into two groups: 1.polietilenovye and polypropylene pipes; 2.truby PVC and metal pipes. Credit: Hachette Book Group-2011. The first group consists of plastic tubes with a higher coefficient of thermal expansion than the plastic tubes, included in the second group.
For example, the extension tube length of 10 m when the temperature rises to 50 0 C for PVC pipe is 26 mm, and pipes made of PP – 90 mm. One of the advantages of polypropylene tubes in comparison with polyethylene (PE) or PVC is their thermal stability. At the present time, many apartments have washing machines and dishwashers, which is given by high runoff (up to 90 C). Polypropylene tubes allow transportation of waste water with a temperature of 95 C, while the maximum temperature for PVC pipe – only 60 C. If a pipe is made of PVC is not deformed under the influence of high runoff used pipes and fittings with the wall of 3.2 mm polypropylene tubes Other than that – it's smaller thickness compared to pipes made of PVC.