Underground Sprinkler Pipe

[carlosgw]

I mentioned in another post that I want to serve a building with two risers. The building is shaped like a wide H. The service comes in at the right side middle. I will put a riser there for the right half of the building. The service comes in, check valve, then riser and a pipe back down underground to the left side for a riser serving the left half of the building. This distance underground is 300-400 feet.
Any issues with this underground pipe? Drainage of the pipe?

The reason I am going underground from one service (instead of two services) is to have the check valve and then one fire department connection that serves the entire building.

 

[cdafd]

Where is the FDc going to be on the building or out in the yard???

 

[carlosgw]

FDC on the building (though I'm not seeing how it has any bearing on the question).

 

[cdafd]

depending on where the fdc is located, gives different ways to run the ug.

should have asked the run to the second riser is it out side the foundation of the building??? as in not run under the building slab?????

it sounds mostly legal, not normally done

 

[carlosgw]

The service will come into the building, go through a check valve, and then a header.
Off the header is the FDC, east riser, and pipe over to the west riser.
The pipe over to the west riser will go underground either under the building or outside the foundation (I would put it mostly outside).

 

[cdafd]

I would disapprove a run under a foundation except about five into a building

 

[Sdpaddler50]

Yup, not sure how far you need to run pipe under the foundation, but i would avoid it if possible. Have you ever seen the result of a broken pipe under a foundation?

 

[carlosgw]

There is actually a detail in the appendix showing an underground vault wth a check valve and the FDC before the service enters the building. I could use this and split off to the two riser locations before entering the building.

I have another project in which there are groups of (6 or 12) apartments separated by breezeways. (it is funny how things seem happen in groups) Here I only need one riser and it would be convienent to come into the end group locate the riser (and FDC) and then go underground to the other groups.

Problem - All piping needs to be drainable. I can not find an exception for underground piping. Am I missing something?

I can solve both by locating the FDC outside like mentioned above with separate risers.
I can solve the first by running a main pipe through the building from one end to the other.
I can solve the second by running the pipe across the breezway in a soffit protected by heat trace.

 

[cdafd]

Hate to ask are you a sprinkler contractor, engineer , other???

You can design however all you want, but is going to fly in the ahj these projects are in????

You do have a copy of Nfpa 24??