dylanlennon ... please see bit for you below...
Earthing and bonding. Good thing the wires know which way to let the current flow. Green with yellow stripe = Bonding, Yellow with green stripe = Earthing --- JOKE ---
Bernard: As you know, I have a lot of sympathies/agreements with your viewpoint, but the case being dicsussed here is obviously an example of a situation in which the 'overlap' between 'earthing' (at least, in one sense) and bonding is not a two-way one. If the gas pipe were main bonded, in the usual way, to the installation's MET, that would certainly also 'earth' it in one sense, since the MET is obviously usually connected to earth via a low impedance path, and usually at a potential fairly close to true earth. However, to earth the gas pipe in the way the OP suggested (installing and connecting an earth rod to it), that would most certainly
not provide the required bonding. On the contrary, it would make it even more certain that if, due to a fault, the MET/CPCs rose to a high potential above true earth, a dangerous potential difference would then exist between the gas pipework and exposed-conductive-parts of the installation.
To dylanlennon: To explain this to you. IF the gas feed pipe could represent a path to earth (e.g. if any of it is buried), which makes it what electricians call an 'extraneous-conductive-part', then there is a requirement for '
bonding'. This consists of a thick (usually 10mm²) wire connecting the pipe (close to where it enters the house) to the 'Main Earth Terminal' of your house's electrical installation (usually near the meter and/or consumer unit), The reason is to prevent a dangerous voltage difference (which could result in electric shocks) arising between the gas pipe (and fire) and other metalwork in the house in the case of certain types of fault.
If the gas pipe is in no way connected to earth, then there is no need/requirement for that bonding - that could be the case if the pipe doesn't go anywhere near the ground and is not electrically connected to earth via the gas cylinder (cylinder raised off ground by insulating material or connected via an electrically non-conducting hose {beware - some flexible gas hoses are electrically conductive}). If any gas regulations require the cylinders to be earthed (I don't know), that could be done in the way you suggest (connect to a local earth rod) - but, in that case, you would definitely have to have 'bonding' of the pipework in the house, as above. Opinions will probably vary as to whether you need that bonding, and you therefore really need an electrician to look at the exact situation to decide whether you need bonding to be installed.
Kind Regards, John