Pipeline Bonding

[jbond]

We have some natural gas piping running to some gen-sets at some power stations.

The piping is metal but it has flanges and the question has arisen as to whether or not we have to bond those flanges for electrical continuity. Threats I am considering include lightning and static charge build up.

Lightning: I presume this is only a threat if the piping is in a flat plain area where there are no trees or tall structures nearby.

Static charge buildup: Is this a phenomena associated with natural gas piping?

The thing is, I checked on the standards and it says "... piping shall, where necessary, be suitably earthed ... to prevent ignition sources from by static electricity and to give corrosion protection ...". So what I'm trying to determine is "if it is necessary" or not.

Any thoughts guys?

Cheers,
Matt.

 

[weh3]

On a cathodically protected pipeline, you have to use isolating flanges after the pipe leaves the ground, and ground the aboveground portion separately. A surge arrester is used to connect the pipe on either side of the insulating flange. Dairyland (I don't know the whole name of the company) makes such a device. Google search on dairyland isolation surge arrester.

Regards,
William