Hi Thorf,
If it is 15mm Hep20 pipe, then it has the same outside diameter as 15mm copper pipe and so this insulation will physically fit it. As to whether it is necessary to fit it to plastic pipe, which insulates better than copper, that is another issue which would need checking.
Thanks for using Screwfix Q&A. JT
Answered by: JTremain
Date published: 2021-10-27