Gas bonding regulations

[EFLImpudence]

IF it is an extraneous-conductive-part.

544.1.2 may be somewhat confusing but it only applies to extraneous-c-ps as per 411.3.1.2.

 

[DaftPunk]

Does the pipe in my scenario constitute an E-C-P?

 

[EFLImpudence]

Not from what you said -

but it could go into the ground inside the premises.

 

[JohnW2]

Metal gas pipe within domestic (maybe also non-domestic?) premises is not allowed, so it is bound to enter the premises as metal.

Typo ?

Whoops Thanks for pointing out. Apologies - corrected!

Kind Regards, John

 

[JohnW2]

Does the pipe in my scenario constitute an E-C-P?

As EFLI has said, I would presume not. As I wrote:

If the gas main is plastic and the transition from plastic to metal pipe (outside of the premises) is well away from 'the ground', then it's possible that it would not count as an extraneous-conductive-part

.. as EFLI has said, that is, of course, only true if the pipe keeps away from the ground (as in earth/soil etc.) once it has turned to metal. People sometimes forget that an extraneous-c-p does not have to come into the premises 'horizontally from outside' - it may come in 'vertically from below the property'!

Kind Regards, John

 

[AndyPRK]

SORRY FOR THE BUMP. IGNORE.
I don't seam to be able to edit old posts.


I just wanted to make a note for myself.

While I had the floor boards up I found the gas bonding wire. And managed to make an educated guess where it connects.
It connects just where there is a T for a kitchen supply.

As it turns out the gas bond is fine and present. (have now marked its location)

However it was the water bond that was poor and corroded!
I have now cleaned this up, and its much improved.
Was getting 1.5VAC between earth and water with it disconnected

 

[AlanE]

Here's a scenario to debate. Gas supply in PE pipe right up to an external meter cabinet then copper pipe into the house straight through the wall from the back of the meter cabinet. Does it require bonding?

Yes.

 

[JohnW2]

Yes.

I don't think that's necessarily true. Only extraneous-c-ps ever need main bonding. If the metal pipe from the outside meter (which, itself, is supplied by plastic pipe), and the meter itself, go no where near 'the earth', the pipe would not qualify as an extraneous-c-p and therefore would not require bonding.

I think many people get confused by the reg which talks about how/where a utility pipe should be bonded. Per other regs, it only needs bonding at all if it is an extraneous-c-p, so the comments about how/where to bond it are not applicable if it does not need bonding at all.

Kind Regards, John

 

[AndyPRK]

On my house, the metal pipe comes out the house, and you can touch/grab is very easily, and then goes into the underground brown meter box.

 

[EFLImpudence]

On my house, the metal pipe comes out the house,

I would say it goes into the house which is what is important.

and you can touch/grab is very easily,

It doesn't matter if you can touch the pipe outside.

and then goes into the underground brown meter box.

No, it comes out of the ground which is the important bit.
If it is continuous metal going into the house then it must be bonded at the point of entry to the premise.



The question was about a plastic - PE - supply pipe.

 

[AndyPRK]

My supply pipe is plastic.

Is it not a concern, if someone is stood outside the house, and touches a pipe which could be at a different potential?

 

[EFLImpudence]

My supply pipe is plastic.

Doesn't require bonding, then

Is it not a concern, if someone is stood outside the house, and touches a pipe which could be at a different potential?

Not as far as main bonding is concerned.
It could be at a different potential to the ground but main bonding to the MET would possibly make it worse (probably not though) but could not make it better.

What you are concerned about - different potential to the ground - would mean you need to bond it to the ground.
Then it would require main bonding inside.

 

[AndyPRK]

If I could be bother to find it, I expect the Gas Safe check list, just says, Check gas pipe has a bond present or similar words


EDIT:

Ok from the one I found, it just asks if it is satisfactory.

http://www.gasfix.org.uk/landlord-gas-safety-certificate-guildford-godalming-cranleigh/

 

[JohnW2]

On my house, the metal pipe comes out the house, and you can touch/grab is very easily, and then goes into the underground brown meter box.

The meter box may be (partially) underground, but does the metal supply pipe (downstream of the meter) come into contact with 'the ground' at any point?

I dare say some people will talk about the possibility of the meter box filling with water (and thereby perhaps resulting in some sort of electrical path to true earth), and I admit that underground meter boxes are more of an issue than above-ground ones, but I'm still far from convinced that I would regard the pipe as an extraneous-c-p which needed bonding.

Kind Regards, John

 

[JohnW2]

If I could be bother to find it, I expect the Gas Safe check list, just says, Check gas pipe has a bond present or similar words ...

It could (although your edit suggests slightly different wording).

In the case of gas, there's not much of an issue, since all gas pipework is necessarily metal, and is almost inevitably all connected to earth via a boiler and/or CH pumps/controls etc. However, if we were talking about exactly the same situation with a water supply, then 'unnecessarily' connecting interior pipework to earth (by bonding), if it otherwise wouldn't be earthed (maybe because of bits of plastic pipe in the installation, then that could theoretically result in someone suffering a (possibly even fatal) electric shock that they would not have suffered in the absence of the unnecessary bonding. I wonder what the legalities and liabilities would then be in relation to the person who had installed the unnecessary bonding?

Kind Regards, John