Why does the PPR inner wire rotate? The rotation of the inner wire of the PPR refers to the situation in which the metal parts inside the pipe of the PPR rotate. The outside of common PPR fittings is made of PPR material, but the inside is stainless steel or copper. It is combined with copper or stainless steel after heat fusion of PPR. The loosening of the inner wire occurs because the combination of the two materials is disturbed for some reason.
