Requirement to pour seal offs if installed

[rodeo619]

I have a subcontractor that has installed some seal off's that shouldn't have been installed due to the location, and NEC requirements, (the conduit comes up outside in a non-classified area before going into an open cable tray with TC cable, and there is a boundery seal coming from the Class 1 Div 2 location, which when I read the code suggests they didn't need to be there). Is there a requirement that they must be poured anyhow?

 

[petersonra]

I have a subcontractor that has installed some seal off's that shouldn't have been installed due to the location, and NEC requirements, (the conduit comes up outside in a non-classified area before going into an open cable tray with TC cable, and there is a boundery seal coming from the Class 1 Div 2 location, which when I read the code suggests they didn't need to be there). Is there a requirement that they must be poured anyhow?

what does the instructions that come with the seal say?

my inclination is that they need to be poured as the fitting is listed as a seal and part of the seal is the sealing dam and sealing material.

 

[Smart $]

... Is there a requirement that they must be poured anyhow?

Not that I'm aware of. Regardless of part instructions, I would not pour unless required.

 

[dicklaxt]

Would you reword the scenario,,,I'm not following it at all.

dick

 

[kwired]

what does the instructions that come with the seal say?

my inclination is that they need to be poured as the fitting is listed as a seal and part of the seal is the sealing dam and sealing material.

The fitting is listed as a seal, is it a violation of the listing to not use it as a seal? If there is no sealant installed isn't it effectively a fitting with access ports?

If you don't need a seal but install a seal fitting, I don't see that you should be required to seal the fitting.

This is one of those nit-picky type of things that I really dislike. I would not be surprised one bit if someone comes up with evidence that this seal loses any listing if installed without the sealant, yet common sense seems to ask what difference does it make if the seal was not required in the first place?

 

[dicklaxt]

Can I safely say this is simply a conduit witha Tray Cable going from a cable tray in a Class I,Div2 area and then across an atmosphere boundary(maybe a building wall) and then going underground in a non hazardous area?

If that is the case then the conduit needs to be sealed within 18" of the boundary and needs to be poured.If the far end of the UG conduit run stubs up into a non hazardous location then you are done.If it is another hazardous area then it also needs a seal at the far end as well.

If thats not the case then could you explain further?

dick

 

[kwired]

Can I safely say this is simply a conduit witha Tray Cable going from a cable tray in a Class I,Div2 area and then across an atmosphere boundary(maybe a building wall) and then going underground in a non hazardous area?

If that is the case then the conduit needs to be sealed within 18" of the boundary and needs to be poured.If the far end of the UG conduit run stubs up into a non hazardous location then you are done.If it is another hazardous area then it also needs a seal at the far end as well.

If thats not the case then could you explain further?

dick

I guess I don't know exactly what he has either, but I understand he has determined the location these seal fittings are installed was not required to have them installed. My suggestion that they do not need sealed is based on the fact that proper seals are otherwise installed wherever they are required. It was also suggested that they are a listed sealing fitting and do not meet listing if sealing compound is not installed - even if in a location where the fitting was not necessary in the first place - that I find to be redundant even if technically correct.

 

[james_mcquade]

i agree with dicklaxt.

when a conduit leaves a classified area, you must put a sealoff within 18" of the exit point.
the purpose of the sealoff is to prevent gasses from flowing through the pipe into the non classified
area and find their way to an ignition source and backfeeding into the classified area.

i don't have my codebook with me right now but its defined in the nec.
regards,
james

 

[kwired]

i agree with dicklaxt.

when a conduit leaves a classified area, you must put a sealoff within 18" of the exit point.
the purpose of the sealoff is to prevent gasses from flowing through the pipe into the non classified
area and find their way to an ignition source and backfeeding into the classified area.

i don't have my codebook with me right now but its defined in the nec.
regards,
james

I agree with that also, but don't believe it to be what the OP is questioning.

If a seal fitting is installed in a place where it was not necessary, it does not relieve you from installing one in the proper location, but if left in place anyway must it still be sealed? That is what I think is being asked here.

 

[dicklaxt]

If a seal fitting is installed in a place where it was not necessary, it does not relieve you from installing one in the proper location, but if left in place anyway must it still be sealed? That is what I think is being asked here.[/QUOTE]


If thats the case then I say no it does not need to be poured.It can remain in place as an item not in use as it is not contributing to anything one way or the other and not causing any safety issues,,,,IMO

dick

 

[rbalex]

Read the last two sentences of 501.15(B)(2) and 501.15(C) Exception; i.e., the boundary seal, if any, doesn't need to be explosionproof.

Truthfully, the last sentence of 501.15(B)(2) is one of the silliest things CMP14 has done since I left the Panel. I would have faught against it had I still been there.

Actually, CMP14 had been attempting to reduce/remove Division 2 bouindary sealing requirements for years. I agree with that, that's why there are so many Division 2/unclassified boundary seal exceptions. However, the implication of the last sentence is that gases may be transmitted from a Division 2 location to an unclassified location; nevermind that there aren't suposed to be gases under normal conditions to begin with - that's why we have a Division 2.

The last sentence should have noted boundary seals between Division 2 and unclassified locations aren't necessary at all except in a few very specific conditions where here is a constant driving force, like a constant positive pressure in the Division 2 location. In most cases, any gases would "free-flow" outside the raceway and across the boundary anyway and would disapate rapidly.

As far as the OP is concerned, the seal isn't necessary and should be treated as a simple fitting; but for the picky - pack it with "ductseal."

 

[dicklaxt]

I guess until we get a clarification as to just what the OP scenario really is we can do nothing but guess as to the requirements.

I do agree Bob on that condition of no driving force but the stipulation about the need would seem to override even tho it doesn't seem a necessity in but a few cases as you ststed.

dick

 

[BPoindexter]

I have seen inspectors come down on both sides of the argument. If a seal is installed but is not required, and it does happen, then is it necessary to pour it? I have always sided with the "not necessary" side of the argument. I have seen seals installed so that an environmental seal as required for temp differences can be put it place although an expenisve solution. In these cases they did as Bob says "pack it with duct seal". We have had contractors mistakenly install seals in locations not requiring them. We do not pour seals in these cases as the time involved and the effort to bust them out isn't worth it, there are no safety issues, and the integrity of the raceway is not compromised. Not sure how most of the guys here have seen it done but most places I have worked paint the seal plugs red when they are poured and green or yellow if used for environmental or not poured. Incidentally at least the inspectors I have dealt with that want them poured do so because they do not want to have to investigate any further to see if the seal is actually required. To give them credit many of them do not have the time to do so even if they wanted.

My 2.375 cents worth

 

[rodeo619]

Thanks for the replies, and let me see if I can clarify things a little bit.

The sealoffs in question are coming up in an unclassified area, 30 yards away from the Class 1, Div 2 location. The question of boundary seals is met by boundary seals inside the hazardous location, within 10 feet of the boundary. The seals at the unclassified location never should have been installed, as they are too far away from the hazardous location to meet the 10' rule regardless. Some good points have been raised in the aspect of the fitting meeting the UL classification in some regards, but in my less than knowledgable, code reading mind, the purpose of conduit of any type is protection of the wire. If the seal off did is job of stopping hazardous atmospheres, but yet could be easily damage, thereby exposing conductors, that would be an issue. These sealoffs are cast iron, and I have difficulty thinking that would be the case, but after the discussions here I suppose it's worth asking that question.

I have the inspector here that turned me on to this site, and you folks have more than lived up to his claims in my mind. Thanks so much.

Oh one last thing, any thoughts with regard to marking. My understanding is that a poured seal off has red paint once poured as an indication that the seal off has been poured. What is your opinion if I don't have them poured?

Once again thanks for all the help, sorry for the delay in response.

 

[dicklaxt]

What is the 10'-rule you are talking about?

A broken piece of anything would be considered secondary and not a design parameter.

I have seen different color codes used,,The one I'm was most used to seeing was,spray it yellow after wire was pulled,checked for function and inspected,red after it was poured and then owner personnel(at/on their on time frame) paint steel gray after area was comissioned and sold.

 

[Ponchik]

You basically have installed seal offs where one is NOT required. Now you want to know if you can keep them but do not use the sealing compound. I think it is OK to keep them and not use the sealing compound.

You spent money on something that was not necessary.

 

[kwired]

Thanks for the replies, and let me see if I can clarify things a little bit.

The sealoffs in question are coming up in an unclassified area, 30 yards away from the Class 1, Div 2 location. The question of boundary seals is met by boundary seals inside the hazardous location, within 10 feet of the boundary. The seals at the unclassified location never should have been installed, as they are too far away from the hazardous location to meet the 10' rule regardless. Some good points have been raised in the aspect of the fitting meeting the UL classification in some regards, but in my less than knowledgable, code reading mind, the purpose of conduit of any type is protection of the wire. If the seal off did is job of stopping hazardous atmospheres, but yet could be easily damage, thereby exposing conductors, that would be an issue. These sealoffs are cast iron, and I have difficulty thinking that would be the case, but after the discussions here I suppose it's worth asking that question.

I have the inspector here that turned me on to this site, and you folks have more than lived up to his claims in my mind. Thanks so much.

Oh one last thing, any thoughts with regard to marking. My understanding is that a poured seal off has red paint once poured as an indication that the seal off has been poured. What is your opinion if I don't have them poured?

Once again thanks for all the help, sorry for the delay in response.

My thoughts on painting the seal off once poured is that it is simply a convenience for the installer to keep track of what they have done. You think an inspector is going to assume it is sealed just because it is painted? I wouldn't. I may not want to check every seal, but am not going to assume the paint means it is sealed.

 

[dicklaxt]

I just did a read on the 10' rule,that is one in my expierence that is seldom adhered to ,it most often is done within 18",in fact it was worked around so often that I even forgot it was there.The statement of no fittings,unions,coupling or box between the seal and the boundary is much easier to live with when 18" is used.

I didn't quite word the red paint application correctly,,,it was done by the owner personel prior to selling/buying the area,,,,,,,,gray at a later time.

dick

 

[rbalex]

Thanks for the replies, and let me see if I can clarify things a little bit.

The sealoffs in question are coming up in an unclassified area, 30 yards away from the Class 1, Div 2 location. The question of boundary seals is met by boundary seals inside the hazardous location, within 10 feet of the boundary. The seals at the unclassified location never should have been installed, as they are too far away from the hazardous location to meet the 10' rule regardless. Some good points have been raised in the aspect of the fitting meeting the UL classification in some regards, but in my less than knowledgable, code reading mind, the purpose of conduit of any type is protection of the wire. If the seal off did is job of stopping hazardous atmospheres, but yet could be easily damage, thereby exposing conductors, that would be an issue. These sealoffs are cast iron, and I have difficulty thinking that would be the case, but after the discussions here I suppose it's worth asking that question.

I have the inspector here that turned me on to this site, and you folks have more than lived up to his claims in my mind. Thanks so much.

Oh one last thing, any thoughts with regard to marking. My understanding is that a poured seal off has red paint once poured as an indication that the seal off has been poured. What is your opinion if I don't have them poured?

Once again thanks for all the help, sorry for the delay in response.

No marking, poured or not, is required "by Code." There may be a local or customer requirement. On one of my contracts where we had several hundred required seals, and not all of them were easy to inspect, we had the field receiving warehouse spray the incoming seals yellow. After they were poured they were sprayed red. It seemed to work pretty well.

BTW I wrote the 10' rule in the mid 90's while I was with the API. Before that, there was no specificity. Eighteen inches (18") was a value arbitrarily applied by some inspectors. As long there were no fittings/couplings/etc. between the seal and the boundary, technically, it could actually be any length. Ten feet (10') was selected simply because it's a standard conduit length. Permitting a reducer at the seal was also my idea.

 

[BPoindexter]

I worked a position as an Inspector where we were required by the Specifications to do 100% inspection of all packing before the seals could be poured. The inspector initialed and dated the the Seal indicating that it had been inspected. After this the electricians could pour the seal at which time they painted the plugs red. I did not mean to infer that painting was required by NEC in my previous post. Seems like the majority use the red paint method.

Another thing I have seen done at every plant I have worked at so far is that the seals are not poured until all pre-commissioning is completed. This is so that changes as required to make the equipment/instrument/circuit make can be readily made. Once pre-commissioning is completed all seals are poured.