LPG Bonding

Guitarist · Jun 1, 2012

This is the only form of bonding on the LPG pipework. Nothing inside the house. TT system, with 30mA CU.
Apparently, this was done by the guy who installed the gas tank 20 years ago.
Bet you guys like the jubilee clip

telectrix · Jun 1, 2012

What's the pipe coming out of the ground. Is it metal or plastic>?

Guitarist · Jun 1, 2012

Galv steel mate.

Engineer54 · Jun 1, 2012

Is there a storage tank in this LPG set-up?? If so, then the tank will need earthing, (usually a rod or other TT electrode) so that the filling tanker can connect it's equipotential conductor to the tank. No earthing and many drivers/operators will not connect the LPG filling pipe to the tank....

Guitarist · Jun 1, 2012

Engineer54 said:
Is there a storage tank in this LPG set-up?? If so, then the tank will need earthing, (usually a rod or other TT electrode) so that the filling tanker can connect it's equipotential conductor to the tank. No earthing and many drivers/operators will not connect the LPG filling pipe to the tank....

The storage tank is about 3M from that pipe. Don't think there is any other bonding except the earthing you see in that photo.
It's been like it for 20 years and not aware of any refusals to fill.

Engineer54 · Jun 1, 2012

Been a long time since i've had anything to do with Gas storage tank installations in the UK, ...and then only industrial sized systems.
But I wouldn't mind betting there will be a designated earthing point on the gas tank frame, in the form of a marked stud with washers and nuts provided. Along with a position for the heavy duty croc-clip used by the tanker to connect to the tank... lol!!!

MarkieSparkie · Jun 1, 2012

Love the jubilee clip termination and the obscured unfixed warning label. Assuming the earth electrode and terminations are good, you can be certain with that the metal LPG pipe will bring an earth potential inside the building and definitely needs bonding. Ha Ha:wink_smile: As E54 says there is usually dedicated earthing point on the frame of metal LPG tanks.

Knobhead · Jun 1, 2012

With other chemical storage tanks I’ve dealt with the delivery driver will connect a bond first. Delivery can then commence. So long as the storage and delivery tanks are connected first it doesn’t cause a problem.
The biggest problem was the tanker driving off with the bond still connected. Had many a driver in the workshop wanting bonding and power cables repaired.

Engineer54 · Jun 1, 2012

Tony said:
With other chemical storage tanks I’ve dealt with the delivery driver will connect a bond first. Delivery can then commence. So long as the storage and delivery tanks are connected first it doesn’t cause a problem.
The biggest problem was the tanker driving off with the bond still connected. Had many a driver in the workshop wanting bonding and power cables repaired.

The problem isn't with the tanks themselves, rather with the delivery tankers that will/can build up a charge. Earthing the tank will discharge any built-up charge and equalize any potential between the delivery tanker and the storage facility....

Those gas tanks our factories along with the gas systems, were regually inspected and tested by the as then factory inspectorate, which i suppose is now HSE... As i remember, the chain linked fence around the tanks also needed to be earthed and bonded to the storage tanks as well...

Knobhead · Jun 1, 2012

Our's were the same, if it doesn't move bond it!
It's a wonder the elecricians weren't bonded to the mess room chairs. OK maybe we were.

Guitarist · Jun 1, 2012

I was planning to bond the pipework where it enters the building in 10mm, back to the MET (as there is no bonding internally at present) and remove this botched earth electrode.
Would you recommend I leave this in place (with a replaced earthing clamp), as it appears to be the only outside bonding point for the tank, via the galvanised pipe which runs under the surface and up?
I will try to get a look at the tank over the weekend and see if there are any other connection points.
Thanks for the comments guys.

Guitarist · Jun 2, 2012

Just out of interest, has anyone actually come across an earthed domestic LFG tank, as has been suggested, or is this normally done for industrial?

Knobhead · Jun 2, 2012

For industrial it's normal. Not sure about domestic.

As I said if it doesn't move bond it!

For domestic as industrial a bonding point should be there, BUT....... You could get the fussy delivery driver..........

Guest123 · Jun 2, 2012

Taken from HS(G)176.

Static electricity
[FONT=Helvetica 45 Light,Helvetica 45 Light][FONT=Helvetica 45 Light,Helvetica 45 Light]134 Static electricity is generated when movement separates charge which can then accumulate on plant and equipment, and on liquid surfaces. If the plant is not earthed or the liquid has a low electrical conductivity, then the charge may be generated faster than it can dissipate. Eventually, there may be an electrical discharge or spark. If this has sufficient energy it could ignite a flammable gas or vapour.

135 To minimise the accumulation of electrostatic charge and prevent incendive sparks, all metal parts of the storage installation should be bonded together and earthed. A maximum resistance to earth of 10 ohms is recommended. It should be possible to disconnect the earthing facilities for periodic test measurement. Further advice on earthing and bonding is in BS 7430: 1991 Code of practice for earthing.

As said, a dedicated electrode for the storage tank and bonding of the supply line where it enters the bulding.[/FONT][/FONT][FONT=Helvetica 45 Light,Helvetica 45 Light][FONT=Helvetica 45 Light,Helvetica 45 Light][/FONT][/FONT]
[FONT=Helvetica 45 Light,Helvetica 45 Light][FONT=Helvetica 45 Light,Helvetica 45 Light][/FONT][/FONT]

Guitarist · Jun 2, 2012

Thanks guys. I'm assuming that the original LFG installer who earthed the pipe (as in the photo) considered it adequate, as the pipework is continuous in galvanised steel.