The input figure (32 kilowatts) for the new open gas fire may seem
excessive, but it is correct - manufacturer's figures.
What size of gas fire is it?! Are you heating the great hall in a castle
or something?
I seem to remember that the copper development agency
(
http://www.cda.org.uk/) has online tables for sizing pipes.
HTH
--
Alistair Riddell - BOFH
Microsoft - because god hates us