Christian McArdle wrote:

If it has worked perfectly for 30 years, then leave it, unless it has failed
an inspection. Without doing the calcs, and assuming few elbows, the run is
probably just below spec. Perhaps someone will be kind enough to do the
calcs for you!

Well if you take a m^3 of gas as 37MJ, assume the boiler is 40k BTU
(11kW ish) that gives you 11000*3600 J / hour, or about 40MJ. So that is
a gas rate of approx 1.1 m^3 / hour.

Lets call the pipe run 9m to allow for some bends etc.

According to:

http://www.cda.org.uk/megab2/build/p...0Tube%20Sizing

9m of 15mm will be good for a gas rate of up to 1.5 m^3 / hour

So you look ok right up until the bit where you mention there is another
appliance on the pipe! ;-)



--
Cheers,

John.

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