Pipe sizing.

[doitall]

Still not with you DIA

12.6 x 3 = 37.7m

38m of 28mm won't carry 5.6m/hr ish of gas, so as I posted I would use 35mm off the meter.

(Yes I know you know how to pipe size )

Why have you x it by 3

Only the first 12.6m will carry the full load

Email me if you want to discuss it of air

 

[doitall]

Taking a shortcut by just calculating the requirements for boiler and cooker adding up to 54 kW, you need about 5 m3 per hour.
As the fire takes only a few percent of the total load, I would personally not include it in the calculation and simply go for a larger size if I came anywhere near the maximum load.
22mm will give you a max equivalent length of about 8 meters, which in your case is not enough, so it must be a least 28 until the first tee, and after that it might still need 28 depending on the route of the pipe.
No need to go larger than 28 as it will give you an equivalent length of more than 20 meters.
The RGI who fitted the pipe, was not required to install the bonding to the gaspipe, and unless he was also a competent electrician, technically not even allowed to do so.
What he should have done is leave you a notice to get it done by a registered electrical installer.

maybe not Bengasman but he is required by law to fit a temporary continuity bond before he disconnected the meter

 

[bengasman]

maybe not Bengasman but he is required by law to fit a temporary continuity bond before he disconnected the meter

Absolutely right. Could not agree more. Guess you mean the 10mm csa cable with the clamps on either end.
Thing is, I am such a tight git that I undo the temporary connection when I am finished with the job and take it with me. guess the Transco boys did the same

 

[doitall]

And possibly left the householder at risk with no earth bonding, This guy sounds a right chancer to be honest.

 

[Spooked]

the first 12.6m is the main feed and is supplying 3 appliances.
when they return i will insist that they put 28mm under the stairs, this will be approx 3.5m of pipe inc fittings. This x3 = 10.5m giving me at least 8m3/h?
More than enough.

doitall, the fire spec says that the cat is good for the life of the fire??
so i hope they have tested the equivalent of forever
Also, the 12.6 of 22mm is the pipe that is carrying the full load so x3 it is 37.8m
You see the problems? There are lots of Corgi members on here yet none agree 100%.
I was reading a thread earlier where kevplumb was having a go at someone who said they were Corgi, he said they couldn't be as they would know basic pipe sizing!!
I think there may be an apology needed

bengasman, not a word was said about the bonding!!
Too many regs, nightmare!!

 

[Corgigrouch]

The cat is indeed good for the life of the fire... when the cat fails, the life of the fire is over....and possibly whoever else is in the room also

 

[Spooked]

Thanks Corgigrouch, i feel much better

 

[bengasman]

the first 12.6m is the main feed and is supplying 3 appliances.
when they return i will insist that they put 28mm under the stairs, this will be approx 3.5m of pipe inc fittings. This x3 = 10.5m giving me at least 8m3/h?
More than enough.

Times 3?????????

‘fraid not. Common misunderstanding that you should multiply due to multiple appliances. Is a bit like parallel conductors; only as rule of thumb when almost identical. And it works on the gasuse or throughput, not on the pipe size.

I would not recommend trying to calculate or deduct required sizes based on the few bits you have read in replies.
Pipe sizing is not rocket science, but it does take a little bit more to get the hang of it than you have seen so far.

Simplest explanation I have seen is in viper book ccn1-5, complete with tables and examples.
Not that I disbelieve you, but it does sound unusual that Transco boys blundered like this. No excuse though

 

[clf-gas]

Still not with you DIA

12.6 x 3 = 37.7m

38m of 28mm won't carry 5.6m/hr ish of gas, so as I posted I would use 35mm off the meter.

(Yes I know you know how to pipe size )

Why have you x it by 3

Only the first 12.6m will carry the full load

Email me if you want to discuss it of air

DIA and G4Y, post it in the chamber, this times three has me as well

 

[Spooked]

bengasman, you need to come see to believe, i have never seen so many fittings and bends, it is almost comical, just to get the 3 metres from meter to first T. 9 elbows, 2 formed bends, 3 couplers!!!!!
Talk about going the long way round, i think this guy used to be a taxi driver

You say you don't need to x by 3??
How can so many fitters have so many differing opinions?
Like i said earlier, the only reason that i am not allowed to fit a neater, safer fix is down to money.
They can go on about safety all they like, i've seen up close in the last few months just how worthless these (safety terms i mean, i know monetary they are far from it) Corgi numbers are!
I think my best bet is get a Transco inspector in and he can decide what's right and what's wrong, then again...............

 

[Balenza]

Diyitall wrote

Why have you x it by 3

Bacause thats the correct way to do it.
Their are no charts available based on a maximum pressure drop of .33 mbar.

 

[Balenza]

BANGasman wrote

Simplest explanation I have seen is in viper book

Yep and it tells you to multiply by three on a 3 section layout.

 

[Spooked]

clf-gas wrote

DIA and G4Y, post it in the chamber, this times three has me as well

Hey you lot, don't go sneaking off, we all want to see how daft you are [/quote]

 

[JohnD]

Spooked, do you see this?

 

[Corgigrouch]

Thanks Corgigrouch, i feel much better

LOL Then my work here is done...Another happy customer.