Thanks all. After a bit more research I am going along with the theory that it is speedfit pipe and I am going to connect my hep2o pipe to it with a compression fitting using a speedfit pipe insert.
I am converting an old kitchen into a bedroom and want to remove the water pipes. They come down from the loft and feed the kitchen sink and then go through the wall to the bathroom.
So I want to bring the pipes from the loft directly into the bathroom. They are copper in the kitchen but the...