Conduit pressure test

[don_resqcapt19]

Has been touched already though that you wouldn't have a coupling between an enclosure with ignition hazards and the conduit seal, in fact I believe (going from memory here) that there is limitations on what fittings can be between the enclosure and the seal fitting, and they are mostly limited to explosion proof unions, explosion proof capped elbows and explosion proof flexible couplings.

I would think a standard coupling wouldn't even be desired in most cases over a union type of coupling for assembly reasons.

It appears to me that the code does permit a standard coupling between the explosion proof enclosure and its seal.

501.15(A)(1)(1) ... Conduit seals shall be installed within 450 mm (18 in.) from the enclosure. Only explosionproof unions, couplings, reducers, elbows, capped elbows, and conduit bodies similar to L, T, and Cross types that are not larger than the trade size of the conduit shall be permitted between the sealing fitting and the explosionproof enclosure

I know that others see the word "explosionproof" as modifying all of the items, but I don't read it that way. I would never install a standard coupling in that location, but I believe that the code permits it.

 

[kwired]

It appears to me that the code does permit a standard coupling between the explosion proof enclosure and its seal.

I know that others see the word "explosionproof" as modifying all of the items, but I don't read it that way. I would never install a standard coupling in that location, but I believe that the code permits it.

I kind of recall you talking about this in another thread, your assumption is the standard couplings are a part of the raceway so if the raceway is acceptable so is the coupling or something along that line of thinking.

Not trying to agree or disagree, I do understand the thought though.

I haven't done a lot of hazard location work, maybe more class II stuff though, but when I have done Class I stuff I can't recall ever wanting to have a coupling between a seal fitting and the enclosure requiring seals, unions and elbows - many times.

 

[don_resqcapt19]

I have never found a need to put a coupling in that location either, but I believe it is permitted by the code. That opinion was also voiced by Bob Alexander, a former member of CMP14, in the other thread.

 

[Fulthrotl]

I have never found a need to put a coupling in that location either, but I believe it is permitted by the code. That opinion was also voiced by Bob Alexander, a former member of CMP14, in the other thread.

yep. when you have a raceway entering or leaving a classified
location, the FIRST fitting must be the seal off. no couplings,
ericcson's, whatever. after than, you can have couplings, etc.

 

[kwired]

yep. when you have a raceway entering or leaving a classified
location, the FIRST fitting must be the seal off. no couplings,
ericcson's, whatever. after than, you can have couplings, etc.

That is for the boundary seal of the classified location, the seal at an enclosure with potential ignition sources in it is a different story, and can have fittings before the seal.

 

[chris kennedy]

What am I missing here-I am sooooo confused:?:?--Why would you transfer radioactive material through conduit instead a more robust, corrosion resistant material?:?

The 4" conduit is a sleeve for the transfer lines.

 

[Smart $]

The 4" conduit is a sleeve for the transfer lines.

Still curious as to type of conduit?

And why not some other non-conduit-type of piping? I realize you are likely not involved in the design aspect of the project and likely cannot answer... but it doesn't make me any less curious. :blink:

 

[kwired]

The 4" conduit is a sleeve for the transfer lines.

OK, so if it is just a sleeve for something else what is the significance of the pressure test mentioned in the beginning?

 

[chris kennedy]

It's 4" PVC. I would guess the pressure test on the sleeve is to help contain a leak if a transfer line is compromised.
I'll get more info next trip.