Mains Gas earthing

[pennywise]

Have a friend that's currently working on a church complex, building 1 is fed via a 3ph head with the gas meter being located within this building, building 2 is totally seperate and has its own 100amp single phase head and meter. The problem being building 2's gas supply is from building 1, just wondering if they have to be totally separated or two bonding conductors run back from the gas meter to the two heads or run a seperate submain to building 2 from 1. I believe building 1 is PME and building 2 is TN-S which still needs confirming. Cheers

 

[snowhead]

Building 1 Gas pipe bonded to building 1 MET.

Building 2 gas pipe at point of entry to building or wherever practical, bonded to the MET for building 2.

There should be an Emergency control valve on the gas at point of entry to building 2, it doesn't matter which side the bond is as both sides are the customers responsibilty

 

[pennywise]

That's what I was thinking, but he was getting contradicting info from a tech line. He's the commercial gas fitter so knows that the valve needs installing. Thanks for the input

 

[Engineer54]

Building 1 Gas pipe bonded to building 1 MET.

Building 2 gas pipe at point of entry to building or wherever practical, bonded to the MET for building 2.

There should be an Emergency control valve on the gas at point of entry to building 2, it doesn't matter which side the bond is as both sides are the customers responsibilty

Just to add a little to Snowheads post.... If the gas pipe passes through/within Building #1 on route to Building #2 then going underground to supply Building #2, you will need to bond this gas pipe as it enters the building and as it leaves the building....

 

[telectrix]

good point, eng54. i assume that's because if the pipe were to be cut in building#1, you'd have 2 pipes independently introducing earth potentials into building#1.

 

[pennywise]

Just to add a little to Snowheads post.... If the gas pipe passes through/within Building #1 on route to Building #2 then going underground to supply Building #2, you will need to bond this gas pipe as it enters the building and as it leaves the building....

pipe is surface between both buildings

 

[Engineer54]

pipe is surface between both buildings

I'd still bond on entry and exit, if the gas pipe is surface ''within'' building #1.


We do the same for all our metalic service pipes that enter and exit buildings. Being a hospital, we have a good many more than most buildings, including bulk medical gases, steam, chilled water, fuel oil, to name but a few!! lol!!

 

[pennywise]

I'd still bond on entry and exit, if the gas pipe is surface ''within'' building #1.


We do the same for all our metalic service pipes that enter and exit buildings. Being a hospital, we have a good many more than most buildings, including bulk medical gases, steam, chilled water, fuel oil, to name but a few!! lol!!

Yep see what your saying, I'll suggest this happens.