In article ,
"Frank McGuire" writes:
There are two single pipe systems - one where the radiator sits on top of
the pipe and would be connected via T pieces, and the other where the
radiator is in series with the pipe and would be connected using elbows.
It's the latter that I'm interested in.

Never seen or heard of this.
You couldn't turn a radiator off, for one.

--
Andrew Gabriel