grounding I beams and tanks

[puckman]

how is grounding of i beams and tanks acomplished in buildings ?
there is a 600 amp. 3 phase 240 volt 3-wire service to the building and i was asked to check the grounds to the building steel and have no idea how that is done.
it 's a very old plant and i don't see any signs of a ground system or ground rods. i like to know how ground some holding tanks.
thanks for any help guys.
storage tanks contain all types of products including flamable products and this one contains a type of alcohol . i think should be grounded. thanks again

 

[barbeer]

It should ("could" may be a better term to use) be as simple as looking for mechanical lugs attached to the ironwork or tank in question with a conductor ran to the grounding point on the system. 250.52 NEC(A)(2) I have never seen a storage tank grounded.

 

[tom baker]

What kind of liquid in the storage tanks?
Underground or aboveground?
If there are pumps attached to the tanks, then if the pump is properly bonded (see 250.104) then the piping is bonded.

 

[lile001]

Grounding tanks

Grounding tanks

It should ("could" may be a better term to use) be as simple as looking for mechanical lugs attached to the ironwork or tank in question with a conductor ran to the grounding point on the system. 250.52 NEC(A)(2) I have never seen a storage tank grounded.

Storage tanks containing class I or Class II liquids below thier flash points would need to be bonded, even if they do not have any electrical equipment on them. You need to eliminate the possibility of static charge building uip on them and causing a spark. Charge could come from an impending lighting strike, in which case you better not be standing there, or from pumping insulating liquids (like gasoline), which can build up charge just like a vandegraaf generator.

Generally, tanks will at least have alarms, which makes them as "likely to become energized" as a building frame or an equipment case. They also may need lighting protection, which also requires grounding and bonding. This gets into NFPA 30 terrtory and some other standards, a bit beyond the NEC we are mostly familiar with.

Generally a mechanical clamp in a drilled hole, with the surrounding paint sanded off, is adequate for tanks. Piping can use standard bronze clamps for water pipes. We usually specify that it be repainted to keep it from rusting.

 

[barbeer]

Well I learned for the day, I can go to sleep now!