... etc. White,green PP-R PipeSize:1---S5 PN1.25Mpa: 25*2.3 , 32*3.0 , 40*3.7 , 50*4 ... *5.8 .2---S4 PN1.6 Mpa : 20*2.3 , 25*2.8 , 32*3.6 , 40*4.5 , 50*5 ... *7.1 .3---S3.2 PN2.0Mpa: 20*2.8 , 25*3.5 , 32*4.4 , 40*5.5 , 50*6 ... *8.7.4---S2.5 PN2.5Mpa: 20*3.4 , 25*4.2 , 32*5.4 , 40*6.7 , 50*8 ... normal palces for long time <700, could choose C=1.25 .If used long time for important places for long time ...