Unions: Code 6.14.4

[Porcupinepuffer]

So a TSSA inspector had told a co-worker he is not allowed installing the unions inside the furnace cabinet. I couldn't find or get any answer about the code, amendment, or any advisory he used to back this up. Upon further research, I believe the inspector is right after I read over 6.14.4 a couple hundred times.

6.14.4
A union or a combination of fittings designed and intended to act as a swing joint shall not be used where piping is concealed.

I used to interpret this as "A union designed and intended to act as a swing joint shall not be used where piping is concealed. A combination of fittings designed and intended to act as a swing joint shall not be used where piping is concealed."

But I now believe it's to be interpreted as "A union shall not be used where piping is concealed. A combination of fittings designed and intended to act as a swing joint shall not be used where piping is concealed."

Number one reason: I've never heard of a situation where a union was designed or intended to act as a swing joint. A true swing joint requires at least 3 elbows to make any sort of sense. Any union I know of that could potentially swing, is a union not tight and a union that will leak gas like crazy.

Number two reason: When I do a search in the codebook for the definition of fitting, it has union listed as a fitting. If you were to write out the code of all the fittings for "combination of fittings" you'd have union already listed.

So a union must be completely on its own from the combination of fittings for a swing swing joint. The furnace compartment is concealed. It's readily accessible, but it's still not allowed.

I know some manufacturers specify whether or not they want the union in or outside the furnace compartment, but our most stringent code seems to dictate it has to go outside everything.

What do you guys think?

[Admin]

I don't think inside the furnace is what the Code considers to be concealed.

Concealed piping or tubing — piping or tubing that, when in place in a wall, floor, or ceiling of a finished building, is hidden from view and can only be exposed by use of a tool. The term does not apply to piping or tubing that passes directly through a wall or partition.

The ICP C9MPD manual says,

Unions may be installed inside the cabinet when necessary because of clearances.

Read these threads,

http://www.hvactechgroup.com/hvacforum/index.php?topic=2077.msg6248#msg6248

http://www.hvactechgroup.com/hvacforum/index.php?topic=1463.msg4029#msg4029

[Porcupinepuffer]

I don't think inside the furnace is what the Code considers to be concealed.

Concealed piping or tubing — piping or tubing that, when in place in a wall, floor, or ceiling of a finished building, is hidden from view and can only be exposed by use of a tool. The term does not apply to piping or tubing that passes directly through a wall or partition.

I agree. I didn't think to look up if they had a definition of concealed piping. I can't see how the furnace cabinet could fall into that category when we know a union will be in the vicinity. Now I'm a really curious for more information from this contractor.

[walker]

it doesn't seem to be "concealed" when you can just pop the furnace cabinet door off.  Its not like its concealed behind a finished wall or ceiling with no access.

[bster352]

I agree that the union mentioned in 6.14.4 should be taken on its own. I personally would not install a union in a concealed location anyway. I also would not consider the furnace a concealed location and you do not need a tool to remove the tool. Just my 2 cents.