Gas pipe sizing

[chr15]

Heres a question I cant quite get my head around-i'm installing a 28kw condensing combi in an extension onto an existing dwelling,the existing house has a BBU and a cooker,I plan to come from the meter in 28mm and then tee the existing 22mm supply to the BBU straight after it leaves the meter and carry on all the way with the new pipe to the new boiler in the extension approx. 20 metres away. My question is,for getting the correct pipe size,do I just calculate the length of the new supply or do I need to add the other appliances into the mix,seeing as they will tee off within 150mm of the meter outlet-the rest of the supply will have no other tees. Sorry if it's a bit technical for Friday night, I need a drink.

 

[bster]

are you an RGI?

 

[chr15]

errrrrr yeh

 

[kevplumb]

are you an RGI?

methinks not

 

[chr15]

I might have known I would get smart arsed answers and not a helpful one-do you all think rgi's never look up stuff in books-Ihave done that but it aint clear,thats why i'm asking.

 

[Agile]

Well for the CORGI engineer installing your boiler then he will be doing the calculation in accordance with his training on pipesizing.

If the 28 kW boiler is really on the end of a 20 m length of supply pipe then I would expect a good part of that pipe length might have to be in 32 mm !

If the CORGI does not get the pipe sizing correct with no more than 1 mB pressure loss then he can be disiplined by CORGI and have to correct the pipe size at his own cost.

Tony

 

[bster]

.........so going by the unwritten rule i will abstain from giving any advice (as it could result in a dangerous situ more than likely because im still a newbie and not because your not an RGI but probably both ) ...no hard feelings

 

[doitall]

Well for the CORGI engineer installing your boiler then he will be doing the calculation in accordance with his training on pipesizing.

If the 28 kW boiler is really on the end of a 20 m length of supply pipe then I would expect a good part of that pipe length might have to be in 32 mm !

If the CORGI does not get the pipe sizing correct with no more than 1 mB pressure loss then he can be disiplined by CORGI and have to correct the pipe size at his own cost.

Tony

32mm Tony, you're not thinking of a length of PE by any chance

 

[chr15]

but 28kw needs approx. 2.6m3/hr so at 20metres in 28mm that would give about 5.8m3/hr so where do you get 32mm pipe size from-or is it that you cant just do it from the top of your head? so referring to books is what we do now and again.

 

[chr15]

.........so going by the unwritten rule i will abstain from giving any advice (as it could result in a dangerous situ more than likely because im still a newbie and not because your not an RGI but probably both ) ...no hard feelings

Nobody knows everything all of the time-RGI or not,and those who reckon they do are lying.

 

[bster]

.........so going by the unwritten rule i will abstain from giving any advice (as it could result in a dangerous situ more than likely because im still a newbie and not because your not an RGI but probably both ) ...no hard feelings

Nobody knows everything all of the time-RGI or not,and those who reckon they do are lying.

nobody knows everything but being able to understand the regulations and interpret the terminolgy requires a specfic knowledge that some people may have and some people may not have. A Judge does not know every law off the top of their head but he can referance AND UNDERSTAND the relevance and terminolgy that allows him to use the law in the required way, due to his localised understanding of the subject.

(ok a judge isnt the best eg!! )

 

[chr15]

So everyone doesn't know everything.

 

[kevplumb]

but 28kw needs approx. 2.6m3/hr so at 20metres in 28mm that would give about 5.8m3/hr

20m actual or calculated length

 

[bster]

everyone knows something but nobody knows everything, i think, I'm confused know or is that now

ps - edited my last post

 

[chr15]

Actual- I know about elbows and tees and stuff but i'll work them out after