In article ,
Colin Swan colin AT nildram DOT net wrote:
My 1930s semi had a Servowarm system fitted when there was a shortage
of copper, and it was done in steel. Some of it has now been replaced
with copper as we have moved stuff around, and I was pleased to see
that the bits of steel pipe cut off appear to be in pretty good
condition. I had been told that it *will* fail, and that any plumber
brave enough to try adding to it will have great difficulty and end up
replacing most of it. Thankfully, this appears to not be the case, but
I keep an eye on it anyway.

Iron barrel was used for piping water and gas before copper became common.
With a central heating system there should be no air in the water, so no
corrosion. But an inhibitor would stop this anyway.

Its modern equivalent is electrical conduit so the skills to form it etc
still exist, although not, I'd guess, with the average plumber.

--
*Why is it called tourist season if we can't shoot at them?

Dave Plowman London SW 12
RIP Acorn