Pressure degree:PN=1.25,1.6,2,2.5 ... , S3.2 have S2, S4, S5 of pipe pressure level 5 series. Nominal diameter from 20 to 160 mm, etc DuoZhong ... with the points, S4, S5 for cold water pipe, series of normal use tube for more than 40 °C the ... fluid temperature, S2 to S3.2 series for normal use hot water pipe, tube, the fluid ... industrial, agricultural tube. PPR hot and cold water pipe series