Where to bond gas?

[F-W]

At the moment my house has no main protective bonding for the gas pipework despite being tncs.

I know ideally the clamp would go straight onto the hard pipework within 600mm of the meter and before any branches. But I’m not sure what the pipe from the meter is made of, maybe some coated iron? It looks like the pipe has been covered in a brown or black material and is flaking. I’m not convinced the bond would be sufficient.

The only nice bit of copper to clamp onto is a pipe feeding the boiler. But this is more than 600mm from the meter and after a couple of branches made with this same pipework.

Has anyone had experience with bonding this type of pipe before? I’ve always been lucky with plain newish copper!

 

[EFLImpudence]

At the moment my house has no main protective bonding for the gas pipework despite being tncs.

Firstly, whether TN-C-S or not is not the criterion where main bonding is concerned - that merely affects the size of the bonding conductor - requiring 10mm².
The criterion is whether the pipes are extraneous-conductive-parts; in effect, are they metal in contact with the ground.
Your pipe looks like it is. What about the supply pipe?

I know ideally the clamp would go straight onto the hard pipework within 600mm of the meter and before any branches. But I’m not sure what the pipe from the meter is made of, maybe some coated iron? It looks like the pipe has been covered in a brown or black material and is flaking. I’m not convinced the bond would be sufficient.

It looks like iron. Scrape off to reveal shiny metal.

The only nice bit of copper to clamp onto is a pipe feeding the boiler. But this is more than 600mm from the meter and after a couple of branches made with this same pipework.

So, not the correct place to do it.

Having said that, does the pipe shown go into the ground or just under the floorboards?
If it does not go into the ground, then the correct place to bond would be the supply pipe - IF it is metal.
If it is not metal, then no bonding is required.


Perhaps we could have a wider shot showing all the pipework.

 

[F-W]

Thanks for replying, much appreciated.

The black pipe shown below is the incoming supply. One side into meter, the other goes below the floor to a yellow pipe that goes under the front drive into the street. Both the yellow and black pipes definitely feel metal/plastic covered metal.

If I understand 544.1.2 correctly, the bonding should be connected to the consumers side of the meter? I'm just hesitant about how much to scrape the metal pipe on the consumer side. I haven't encountered this coating before, it is really thick and looks like maybe brown joint compound smeared over black iron. I imagine it is like painted pipe and needs to be removed before clamping? Shame wire wool won't work.

Under the floor the coating on the pipes looks more worn, but it splits straight into a t junction and is inaccessible for me to fit a clamp.

 

[EFLImpudence]

The black pipe shown below is the incoming supply. One side into meter, the other goes below the floor to a yellow pipe that goes under the front drive into the street. Both the yellow and black pipes definitely feel metal/plastic covered metal.

Ok.

If I understand 544.1.2 correctly, the bonding should be connected to the consumers side of the meter?

You do understand 544.1.2 correctly, however it is wrong. Yes, it is.
It is the pipe coming in from the street which might be an extraneous-conductive-part and should be bonded if it is.

As it is plastic covered, it might not be. Perhaps that is why it is not bonded.
However, as the gas pipes will be connected to the earthing of the installation by CPCs(earth wires) of a boiler etc. then unnecessary bonding will not present a hazard.

If you are going to fit a Main Protective Bonding conductor, fit it to the incoming pipe.

I'm just hesitant about how much to scrape the metal pipe on the consumer side. I haven't encountered this coating before, it is really thick and looks like maybe brown joint compound smeared over black iron. I imagine it is like painted pipe and needs to be removed before clamping? Shame wire wool won't work.

Doesn't matter; not relevant.

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