3PP mainly meaning every pipeline has three PP layer：The first layer is FBE（50-100um），The second layer is AD（250～400um）,The third layer is PP(1.4～4.0mm)。Three kinds of material  mixed  together one organic whole, become solid combination with steel pipe forming excellent anti-corrosion layer,use temperature up to 110 degree.
      2PP mainly say every pipeline has two PP layer:The first layer is AD,the second is PP,two material mixed together one organic whole,thickness of every layer is same as 3PP.3PP produce process as follows: