Anyone got their books handy? Pipe sizing Q?

[Slugbabydotcom]

I capped of a fire the other day. There was a run of 9m of 8mm pipe feeding a 6KW gross gas fire. I know it's not right I just want to know how not right it is. What is the longest run of 8mm you can have for that input?
On the same system I capped off an illegally installed flueless fire with no ventilation also a leaking hob with a modified tap connector and no isolation valve.
Its a pity the landlord in question didn't spend as much on the gas installation as he did on the high quality block flooring thats down in there!

 

[clf-gas]

I get

3600 X 0.49 X 10.76 = 18980.64

18980.64 / 3600 = 5.27

So, 9m of 8mm will pass .49M3/hr which equals 5.27kw

The decision is yours John.

Oh, and what you doing up at that hour thinking about this

 

[namsag]

Sure it says somewhere no more than 1metre of 8mm for a fire, Which is why fire chromes never came in longer lengths.
Will see if i can find it

 

[doitall]

My tables don't go down that far, but 6m of 10mm, no fitting allowed, is right on the button.

That also assumes the pipe has been de-burred.

 

[gas4you]

Sure it says somewhere no more than 1metre of 8mm for a fire, Which is why fire chromes never came in longer lengths.
Will see if i can find it

Totally agree, no more than 1metre in 8mm.

 

[ollski]

Would it not be easier to gas rate it?

 

[namsag]

Tables in the book says typical fire uses 0.5m3/hr and a DFE 1m3/hr.
Tables only go down to 6metres of 8mm and that has a discharge rate of 0.29m3/hr so it looks like max length is around a metre

 

[clf-gas]

Got a pipe chart, I'll scan it and post it in the chamber (if I can do it on this unearthly devils advocate of a contraption).

 

[lightning]

6 kw x 0.09=0.54 m3/h

would you not have to use 12mm= 0.85m3/h for 9m

as 10mm 0.5 at 9m would be to close

if wrong then i have learnt something today

 

[namsag]

The question is about 8MM so why are people answering about 10mm and 12mm and what is so special about tables they have to be posted in secert . They are openbly published in the corgi book

 

[Slugbabydotcom]

Books are in my old van. I haven't moved all the stuff out of it yet into the new van.

Convention is to run 15 up to chimney then 8mm to fire but I would have normally let it go if I could have justified the small pipe with a calculation assuming the correct working pressures were achieved. This not being a 'normally' I need some ammo to fire back just in case I get a query.

With the other stuff thats gone on there I have no trust in the previous installer and if I knew who he was I would grass him up. The afore mentioned tap connector was left in a leaking state and there was also a leak on the meter pipework. If I as a corgi had done that I could be facing some big fines.

The house had been renovated for a private landlord by persons unknown to me. Everything was a face job including the lovely electric shower that had no pipe or wire to it.

Oh, and what you doing up at that hour thinking about this

I am not losing sleep over it I am just nocturnal. ....

Thanks 4 everyones help BTW

Ok I confess I am a vampire

 

[ChrisR]

[code:1]p = 1840259.4(Q^2 Lf)
d^5[/code:1]
where

[code:1]f = 0.0044(1+43.5/d)[/code:1]