conduit seals for cathodic protection

[lefty]

I search threads for cathodic protection and found none, so I'll post here. A
customer wants us to seal off the conduits on an existing installation where
the conduits go over the dike wall of a bulk storage facility, the existing conduits are not. This is a tank that holds JP-8, Class1, Div.2 area to the dike. Beyond that unclassified.

There are two conduits of three are for the cathodic protection of the tank,
and they are there to take readings of the cathodes in a remote unclassified area. I was preparing to put seals at the dike on these 2 conduits and the other remaining one, which will need one it is control wires. I was told that the 2 conduits for the cathodes do not need to be sealed.

What are your thoughts and where could I find more info to back this up, I'm thinking where this is a boundry, and cathodes do have a minute amount of voltage, that a seal would be required. The NEC tells us to place a seal for the boundry of an classified area.

Lefty

 

[Rockyd]

A
customer wants us to seal off the conduits on an existing installation where
the conduits go over the dike wall of a bulk storage facility, the existing conduits are not. This is a tank that holds JP-8, Class1, Div.2 area to the dike. Beyond that unclassified.

There are two conduits of three are for the cathodic protection of the tank,
and they are there to take readings of the cathodes in a remote unclassified area. I was preparing to put seals at the dike on these 2 conduits and the other remaining one, which will need one it is control wires. I was told that the 2 conduits for the cathodes do not need to be sealed.

What are your thoughts and where could I find more info to back this up, I'm thinking where this is a boundry, and cathodes do have a minute amount of voltage, that a seal would be required. The NEC tells us to place a seal for the boundry of an classified area.

Lefty

Customer wants an upgrade? Willing to pay? Definitely would go with oversafe, than not safe enough. This may lead to further opportunities to step up some safety issues/survey of the plant to be compliant with standards.

NEC help @ 500.4(B), 500.5, 501.15 in it's entirety. Hope that helps.

 

[don_resqcapt19]

If I understand the installation correctly, 501.15(B)(2) Exception #4 says no seals are required for any of the conduits.

 

[lefty]

If I understand the installation correctly, 501.15(B)(2) Exception #4 says no seals are required for any of the conduits.

Yes, now I have to make sure that all of those items in the exception are met, thanks I read over that yesterday and I was wondering if there was something particular that i missed elswhere about cathodes.

Thanks for your response

 

[rbalex]

When API conceived Exception No. 4 it was only intended to cover item (2) since boundaries in pipeways and other open air locations may ?wander? as facilities develop. It then became a camel (a horse designed by a committee ? I know, I was there when it happened )

With the possible exception of item (4), all of the other items already have solid rules to determine when and where a seal may be necessary. In my opinion, even item (4) is questionable since anything that is likely to be transmitted via the raceway is at least as likely to be transmitted via the open air. [item (2)]

The ?trap? however, is item (5). It is quite possible that the cathodic protection wiring interface enclosure would not normally need a seal (no arcs, sparks or heat producing components). Again, I personally don?t see a need for a seal at either the enclosure or the boundary if that be the case, but it still eliminates using Exception No. 4.

 

[lefty]

501.15(B)(2) Exc. 4

501.15(B)(2) Exc. 4

Thanks for the help fellas, we meet all the exc. 4 rules. But however the Corps of Engineers stated it shall be done. I have finally got my hands on the contract documents............it states it shall be done as a provision of the contract. So we will do it. I tried to upload the picture, but the file is to big, I'm still trying to figure this out.

Thanks,