PPR pipe is divided into S5, S4, S3.2, S2.5, S2 five series, the corresponding pressure level according to the total use factor C of the pipeline system is different:
When C=1.25, corresponding nominal pressure 1.25,1.6,2.0,2.5,3.2MPa;
When C=1.5, corresponding nominal pressure 1.0,1.25,1.6,2.0,2.5MPa;
These five series of hot and cold water pipes can be used, but because the service life of the PPR pipe will be greatly reduced in the case of higher temperature, it is generally a higher pressure grade to choose the hot water pipe than the cold water pipe. PP-R pipe has S5, S4, S3.2, S2.5 and other four pipe series, usually hot water pipe has S3.2, S2.5 two pipe series, cold water pipe system with S5, S4, S3.2 three pipe series, in the pipe system design, according to different requirements, the safety factor can be 1.25 or 1.5, In home decoration, S5 and S4 are generally used for cold water pipes, and S3.2 and S2.5 are used for hot water.
When C=1.25, they correspond to nominal pressures
S5-1.25Mpa, S4-1.6Mpa, S3.2-2.0Mpa, S2.5-2.5Mpa, S2-3.2MPa
1, when selecting the cold water pipe, the water temperature does not exceed 60° for a long time, the system working pressure such as 0.8Mpa, plus the water pressure of 0.25Mpa(industry experience), that is, 1.05Mpa, and then multiplied by a safety factor 1.2 (safety factor according to the working condition), that is, 1.26Mpa. More than S5(1.2Mpa) at this time should choose S4(1.6Mpa), and so choose a higher level of pressure.
2, when selecting the hot water pipe, the water temperature exceeds 60° for a long time, directly start from S3.2(2.0Mpa) to select, such as when the system working pressure is 0.8mpa: nominal pressure =(0.8+0.25)*1.2=1.26Mpa, then select S3.2(2.0Mpa); When the system working pressure is 1.5mpa: nominal pressure =(1.5+0.25)*1.2=2.1Mpa, S2.5(2.5Mpa) should be selected;
When the system working pressure is 2.2mpa: nominal pressure =(2.2+0.25)*1.2=2.94Mpa, at this time, S2 (3.2Mpa) can be chosen theoretically, but it is very close, for safety reasons, PPR pipes should not be selected, and metal pipes should be considered.