cleaning inside of pipe

[Dean Heighington]

Is there anything I can pit down a black iron 3/4" pipe whilst it's in situ to clear it of deposits from use within domestic cold water feed from storage tank in loft? I'd like to have replaced it with copper or hep bit it's impossible due to the route it takes to the bathroom. I have it uncapped in the loft but the run goes down through a disused chimney breast and doglegs into the bathroom floor. Before I connect it to the new tank in the loft, what can I put down it to try and unfur it? I think most of the detritus must be rust. Can I use Sentinel x400? Or is ther anything better? I can trap it in the pipe and let it react before flushing through.

Any ideas?

[Dean Heighington]

Sorry my mistake. It's a grey finish exterior so must be galvanised?! It seemed to be the female-female iron at the top (after an elbow to receive a bush down to copper) that was well blocked. I gave this a good clean and flushed the pipe... Lots if s**te emerged, much to my satisfaction. Flow now seems pretty decent although I still would like to be able to replace the whole lot, but if not impossible then unfeasible!