... 1,Non-posion,corrision-resisting,high mechanical strengthk,low brittle temperature and long wearing,2,Little liquid resistance,uneasy-fouling, ... 100%-insulating from oxygen,thoroughly abolishing permeation,able to use for communication lines shiedle,combtaing various kinds of ... making pipe straight back.4.They are suitable for use in residential buildings,hospitals,schools ,office buildings,libraries, ...