NFPA 13 (1999) requires auxilliary drains for trapped sections of wet piping (5-14.2.5.2). There is no such requirement for a 13R system however there are some references to providing for system drainage. How do you folks treat a trapped section of wet piping in a 13R system? Do you think it has to be provided with a drain? Thanks for your input.
I agree with you. The only reference I am aware of is for auxiliary drains on dry pipe systems where trapped sections are subject to freezing. (NFPA 13R 6.6.2.4) It does not appear that NFPA 13R wet systems have the same requirements for auxiliary drains as wet systems in NFPA 13.
However, I have seen auxiliary drains on NFPA 13R systems.
I'll do a little more research and see if I can find out what the logic is behind the lack of auxiliary drain requirements in NFPA 13R.
All sprinkler systems need to be able to drain regardless of the type of installation. 13R systems are usually plastic pipe, installed in attics and breezways and more suseptable to freezing and breaking. I would check the pitch of the pipe to make sure that it allows drainange toward the drain valve and is not installed incorrectly. If the pitch is such that it creates a low point, than the AHJ can certainly require an auxillary drain to be installed. You can always remove a sprinkler head at the low point and drain the system then have the sprinkler contractor blow out any remaining water (could be messy). Frank Teevan
Thanks for your comments. The problem we're trying to resolve is a design in which the piping is installed under the slab of a breezeway separating an apartment building into 2 sections. This creates a trap but 13R doesn't appear to have any language which would prohibit such an installation. 13 clearly requires all piping to have drain provisions but 13R does not. Additionally, the designer has a valid point in that piping in the attic is much more vulnerable to freezing than piping underground if the originally required insulation is compromised or poorly maintained.
Fairfax County has extensive experience in the type of installation that you are talking about. You can contact Dave Thomas at 703-246-2126. Dave is the supervisor of the Plans Review Branch and a VFPA member. My recollection from my Fairfax days is that the line was copper and sleeved through the slab to allow for removal if necessary. The idea was that the buried copper line would not freeze and break vs. a plastic line run accross the breezeway in an insulated void that could be subject to freezing. That portion of the 13R system is considered an underground supply line and underground lines do not need to have drains. So if there is a problem they have to excavate it and replace it. Hope that helps. F. Teevan
