Dry Pipe System Size
Dry Pipe System Size
(OP)
I have an old 3 story hotel that has a walkway that loops the entire building for 3 floors and is exposed to the elements. Think of an old hotel where the stairs are exposed and so is the wrap around covered walkway.
Our thought we be to install a new dry system that is installed and loops this walkway and then run lines into each room. They are converting it to homeless shelter. My issue is with the system size, the Dry system will easily be over 750 gallons per floor so I am thinking about diving each floor into 2 systems.
But then I run in NFPA 13 (2013) section 7.2.3.1.1 which states that any dry pipe system protecting dwelling unit portions of any occupancy shall deliver water in 15 seconds to the test connection. It also states that I cannot use sections 7.2.3.2, 7.2.3.3, 7.2.3.4, but I can use 7.2.3.5 which talks about dry pipe systems being calculated for delivery times per Table 7.2.3.6.1
So am I going to be stuck with 15 seconds or can I use the table under light hazard for 60 seconds delivery time?
Thanks for the help!
Our thought we be to install a new dry system that is installed and loops this walkway and then run lines into each room. They are converting it to homeless shelter. My issue is with the system size, the Dry system will easily be over 750 gallons per floor so I am thinking about diving each floor into 2 systems.
But then I run in NFPA 13 (2013) section 7.2.3.1.1 which states that any dry pipe system protecting dwelling unit portions of any occupancy shall deliver water in 15 seconds to the test connection. It also states that I cannot use sections 7.2.3.2, 7.2.3.3, 7.2.3.4, but I can use 7.2.3.5 which talks about dry pipe systems being calculated for delivery times per Table 7.2.3.6.1
So am I going to be stuck with 15 seconds or can I use the table under light hazard for 60 seconds delivery time?
Thanks for the help!





RE: Dry Pipe System Size
Travis Mack
MFP Design, LLC
www.mfpdesign.com
"Follow" us at https://www.facebook.com/pages/MFP-Design-LLC/9221...
RE: Dry Pipe System Size
RE: Dry Pipe System Size
Those little standard secreats no one talks about.
But, I don't think I have personally seen a dwelling dry pipe system, plus it just started in 2010
RE: Dry Pipe System Size
RE: Dry Pipe System Size
RE: Dry Pipe System Size
Thanks,
RE: Dry Pipe System Size
RE: Dry Pipe System Size
Here is another one how about insulation on the pipes using UL listed tape for the pipes. I think you can get heat tape for up to 6".
RE: Dry Pipe System Size
To even use in in a 13 system, it must be listed. To date, there are none when I last checked.
RE: Dry Pipe System Size
RE: Dry Pipe System Size
Your system is residential so 7.2.3.1.1 applies.
Do you have a copy a FDT? It might save you a lot of guess work...
R/
Matt
RE: Dry Pipe System Size
RE: Dry Pipe System Size
Now I get to thinking, can you use computer trip times for Residential...?
RE: Dry Pipe System Size
DWELLING UNIT: One or more rooms arranged for complete, independent housekeeping purposes, with space for eating, living, and sleeping; facilities for cooking; and provisions for sanitation.
In my world I would not treat the exterior egress path as part of the dwelling unit for the purpose of water delivery time because the loss history data in NFPA 13R Table A.1.2 clearly shows this area is where the fires occur. I understand this is a NFPA 13 system and the exterior walkways would require AS protection. However, possibly excluding those areas by dividing your design for the dwelling units with one set of DPVs and the balconies with another could make the 15 second delivery time easier to achieve.
It would be a question to your AHJ.
RE: Dry Pipe System Size
Travis Mack
MFP Design, LLC
www.mfpdesign.com
"Follow" us at https://www.facebook.com/pages/MFP-Design-LLC/9221...
RE: Dry Pipe System Size
That is something I will be recommending to the owner.
Thanks,