Just to start an argument.

[ExArmy]

gas has to be done in copper, so my argument is why can you not connect a gas bond to most conveinient place possible as theres no way sections could be done in plastic.
I suppose theres a possibility that that particular branch of gas pipe could be removed which would mean the gas bond could become disconnected, but all this work should be done by a competent person and they would know that and bond the gas from the next most conveinient place.

 

[jaresquire]

I think cornburn (!) was being sarcastic

 

[sambotc]

What about if your gas pipe goes from copper off the meter to mild steel then back to copper again, not uncommon in local authority housing where pipework was concealed in floor screeds or behind plaster? What does the lead in every fitting do to the resistance, or the brass fitting if compression?

Too many variables to make an across the board decision in my opinion.

 

[johnboy6083]

It is permitted to use any extraneous metalwork as a bonding conductor anyway, so in theory you could bond at the closest point to the CU. this is an academic point though due to the points already raised regarding joints, plastic sections ect.

 

[Knobhead]

I thought this was dead and buried.

But let the argument continue. Anything to prove the regulations wrong.

 

[telectrix]

tony, i like your thinking. as douglas bader once said, " rules are made for breaking"

 

[B16 Tom]

Ahhhh That must of been cus thay drank to much and smoked to much.

 

[SparkyJoe]

its so we can find it ;p

 

[johnboy6083]

I thought this was dead and buried.

But let the argument continue. Anything to prove the regulations wrong.

It was, until you linked to it from another post. also i like playing devils advocate, and promoting technical discussion.

anyway about rules. The main ones i hate are specifications drawn up by some clients, often they are a one spec covers all situations. Im a spark, and sometimes i know when im right, and they are wrong! I suppose its their money.

Cant you tell i work for a company and not myself!!

 

[Knobhead]

Like you John, I’ve always worked for companies.

I’ve worked most of my life under M&Q reg’s. Woe betide you if you stepped out side those rules. They make the 17[SUP]th[/SUP] look like Alice in Wonderland. We had a new plant installed to the then 15[SUP]th [/SUP] edition it was condemned out of hand, it didn’t meet our standards for isolation and earthing.

The bible says in big letters “requirements for electrical installations”. They are not rules or legislation, they should be regarded as guidelines. But unfortunately if you step out side those lines the men in suits will jump on your wallet or soul.

Where this thread started was the stupidity of running a 10mm from the MET along side a copper gas pipe that is a better conductor than the 10mm! It’s one of the most glaring points of ineptitude in the 17[SUP]th [/SUP]and it’s precursors.

I loved my work, but now I’m glad I’m out of it. Common sense has gone out of the window!
Physics and chemistry are what started our trade, where have the basics gone?

 

[Guitarist]

Physics and chemistry are what started our trade, where have the basics gone?

Out of the window with "basic" training mate...

 

[Engineer54]

I think the reasoning behind the ''within 600mm'' rule for bonding conductors is that the bonding position is going to be ''Before'' any splitting of pipe runs. Which makes sense in respect of Gas as many a time pipes have been disconnected and isolated when not wanted anymore. And where water is concerned, sections being isolated by plumbers using plastic piping etc....

It is in reality, down to using a bit of commonsense in most instances, where you make your bonding provision points....

 

[telectrix]

don't be silly. where pipes are concerned, plumbers are involved. there goes your common sense, out with a whimper, not a bang.

 

[Geordie Spark]

do gas pipes not have to be in copper throughout?
also are they not required to be 22mm now, i've just had my combi moved and the gas supply is done in 22mm

Yes they do have to be in copper throughout - unless you use Tracpipe which is I think stainless steel, supplied in coil form (like cable & plastic pipe) and is convoluted to make it easy to bend. It is joined by using special compression fittings which cost the proverbial arm & leg.

In recent times, some very powerful combi boilers have been introduced (> 40 kW) and these sometimes require the gas pipe to be 28mm. Because of this gas fitters working on the domestic side of things have been allowed to work on pipes up to 32mm diameter where the previous upper limit was 28mm.

 

[Inteificio]

Given that the specific gravity of copper is 8930Kg/m³


I think you will find it is not. I could explain, but that would detract from an argument.