Gas sizing chart

[bikerbas]

Try the link provided its a lot easy to work out.
45m seems a lot of pipework and elbows
http://www.ukcopperboard.co.uk/lite...ion-Tips/Domestic-gas-planning-and-sizing.pdf

 

[Toddyplumb]

Ive never done it that way . I just use my old CITB way gas rate then calc length / max length to give actual pressure loss in each section .
So for your 3m3 over 15 metres 22mm copper gives 1 mbar calculated drop No good ( Debatable ? NO ) so 28 mm gives less than 0.5mbar (using max charted length of 30m)
You obviously need your flow chart for this Hope you understand it

 

[GPSNewcastle]

I dont understand the way you have gone about calculating this, mainly because of the reference to "3 legs", as far as I know the calculation is from the meter to the appliance with an allowance for fittings and a max drop of 1mbar from meter to appliance. If the length from the meter to the appliance is about 9m I dont understand how you have come to 45m

 

[Toddyplumb]

I had never seen it either but it is in the CORGI book like that . I had a look last night . I suppose its like all these things its horses for courses as to the method you use .
But with my method you dont need to find 45metres !

 

[GPSNewcastle]

Same here...and I dont have a problem with gas rates! I think anyone using this method will be oversizing pipework and crippling their margins! Haha

 

[buckley plumb]

im changing to the other method. well at least i know if my customers want to upgrade in the future they should be ok lol.

thanks for the advise ant