PVC pipes are smooth to outside and inside, standard caliber ... Zhuoxin Plastics CO.,Ltd.) that produce plastic fittings (PPR / PVC fittings), plastics ball valves, plastic taps and mould, ect ... .Best Regards,Zhuoxin Group. 1.The sizes of PVC pipesPVC inside (mm)SIZEDiameter CNS standardJIS standardDIN standardANSIBS( ... ±0.37.1±0.5114.3114.3 2.PVC pipes advantage1)PVC pipe is low in wasted energy, it's ...