Exposed Fire Service Piping

[canman]

Hi everybody, I could sure use some advice on this one. I need to provide a 6" fire service line to a building here in Southern California that is on private property. Normally this would not be an issue but the building fire riser is exposed along the wall of the basement floor outside of the building. The owner doesn't want to dig under an existing retaining wall which separates the building from the ground, thus allowing for an open staircase down to the basement. He wants to core drill about 3 feet down the retaining wall and then turn the pipe 90 degrees south. The pipe would run vertically along the wall to the botoom of the basement then turn 90 degrees again and connect to the fire riser. Since this pipe will be exposed to the weather and feed a building fire riser my questions are as follows:

1) Can I use flanged ductile iron pipe in lieu of steel or copper.
2) If I use ductile iron pipe should it have a minimum 1 mil thick asphaltic coating? I think the exposed pipe should be painted red but would paint stick to the coating?
3) This is southern california, thus should this pipe have some sort of seismic protection such as flexible restrained fittings per NPFA requirements?

Thanks for the help in advance - Canman

 

[SprinklerDesigner2]

1) Can I use flanged ductile iron pipe in lieu of steel or copper.

Yes. IMO it would be superior to regular sch 30 or sch 10 pipe.

2) If I use ductile iron pipe should it have a minimum 1 mil thick asphaltic coating? I think the exposed pipe should be painted red but would paint stick to the coating?

I am not sure of the thickness but underground ductile iron pipe comes with a protective coating and there aren't any requirements for painting pipe a certain color.

3) This is southern california, thus should this pipe have some sort of seismic protection such as flexible restrained fittings per NPFA requirements?

Absolutely.

Rather then use flanged joints I would consider using grooved ductile iron pipe coupled with flexible grooved couplings. Certain Victaulic couplings are listed for direct bury and come with a galvanized coating.

But then I come from far South Georgia and Northern Florida so I haven't had much experience (actually any) with seismic requirements.