... have S2, S4, S5 of pipe pressure level 5 series. Nominal diameter from 20 to 160 mm, etc DuoZhong ... 50 specifications. Hot and cold water pipes 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 ... air tube; Other industrial, agricultural tube. PPR hot and cold water pipe series