The Gasman Cometh (Earth bonding the gas pipe)

[HDRW]

(This is the second time I've posted this - the first one disappeared in a cloud of "Could not insert new word matches" )

I had my gas meter changed a few days ago, and having dug it out of the jun... valuable stuff under the stairs, I found there is no Earth bonding to be seen.

I understand that according to Part P I can install this without involving Building Control.

Now, the only bare metal is on the incoming pipe - past the meter it's all painted. Can I assume the gas meter bonds across its pipes, or do I need to clean the paint off the house-side pipe? (Even I'm not daft enough to put the clamp onto paint!)

If the latter, do I need to clean the whole circumference to the width of the strap, or would cleaning a patch for the clamp-body be enough?

And finally, what's the actual requirement for a gas pipe Earth bond wire - I've seen several sizes quoted, but should it really be 6, 10, 16mm²? I have some nice 84-strand 6mm which is really flexible and lovely to work with, and I'd like to use that if it's big enough (the MET is only about a metre away incidentally, but is through a wall).

Cheers,

Howard

 

[plugwash]

you should clean a complete ring to put the clamp on the pipe to ensure good contact.

10mm is the normal requirement for bonding on domestic supplies with a TN-S or TN-C-S (pme) earth. 6mm is generally acceptable for a TT unless you live in an area with extremely conductive soil but 10mm is advisable in case a descision is made to change to TN-C-S later. some DNOs reccomend 16mm on PME supplies but there is nothing in the wiring regs that requires this (unless the neutral core in the supply cable is more than 50mm but thats very unlikely on a domestic).