The PPR pipe pressure class printed on a pipe \u2014 PN10, PN16, PN20 or PN25 \u2014 is the nominal pressure the pipe holds for 50 years while carrying cold water at 20°C. That is the single number that decides whether a line survives a decade of hot service or splits early, and it is the specification importers and installers most often get wrong. PN is not the pressure the pipe holds when it is running hot; heat lowers the safe pressure sharply, which is exactly why the class you pick matters.<\/p>\n\n
This guide breaks down what each class means, how the S-series and SDR ratios set the wall thickness behind them, and which class belongs on a hot line versus a cold one. For the full material and installation picture, start with our PPR pipe guide<\/a>; here we go deep on pressure alone. The short version: PN20 is the standard choice for hot potable water, and the only reliable way to confirm you actually got PN20 is to measure the wall.<\/p>\n\n