Have a project which has a remote fire department connection outside of the main building. The fire department connection has its own dedicated feed that goes from the remote FDC, underground, up into the building, where it connects to the fire sprinkler riser downstream of the backflow preventer.
The check valve for this line is required to be inside the building, so the main between the FDC and check valve in the building is intended to be dry. NFPA 24 (if that applies) allows PVC for underground water service in its table of permitted pipe types. NFPA 13 specifically states that galvanized steel is permitted to be used between the FDC and the check valve serving the FDC. I can't see where NFPA 13 would mandate pipe types for this arrangement. Is this underground FDC feed allowed to be PVC? Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe
9 Comments
Wes
5/15/2020 09:59:40 am
A few references:
Reply
Casey Milhorn
5/15/2020 12:47:28 pm
Lots of great comments. One additional thing to watch for is the class of C900 pipe. Years ago DR-18 was listed to 150 psi if I remember correctly, which ruled it out for use on an FDC line that may be pressurized over that. Now DR-18 is listed for 235 psi, and DR-14 is listed for 315 psi (from memory, did not verify the pressures). So in most applications DR-14 and DR-18 should be acceptable as long as the application isn't in a fire district where there SOP require pressures over 235 psi. You definitely probably want to avoid DR-21 or 25.
Reply
Mike
5/15/2020 10:30:27 am
Why is the check valve required in the building?
Reply
Wes
5/15/2020 10:32:49 am
The AHJ is requiring it inside the building - I'm guessing so that it is accessible for testing and not buried below grade.
Reply
Shane
5/15/2020 12:52:51 pm
I had the same question on the check valve location in reference to the FDC. I have always put the check valve close to the yard FDC to keep it full of water to prevent all the air being pushing into a system during a fire. Although, I have recently be corrected in rather rude response that I should know my code and to look up, NFPA 14 6.4.2: Locate the check valve as near as practicable to the point at where it joins the system. I understand keeping the pipe dry in freezing locations, but I am in Florida.
Reply
Rob
5/15/2020 11:08:46 am
On a lot of projects, the piping for the fireline and remote FDC line are on the Civil Drawings and will call out the materials based on local requirements. In a lot of jurisdictions what materials and installation practices are dictated by the local municipalities public engineering department or water department. Usually what I have seen even in a dry remote FDC line is either C900 or ductile iron pipe, usually with a ductile spool (flanged) to come up above grade. Hope that helps.
Reply
Jonathan Joseph
5/15/2020 11:24:00 am
I don't see a problem with the pipe material as long as you restrain it well and make sure it is at least 1 foot below the frost line.
Reply
Richard Mercer
5/15/2020 12:27:39 pm
You did not mention the version of NFPA 13 the Jurisdiction references. the 2019 NFPA 13 Hand Book had an FAQ for table 6.1.1.1.
Reply
Wes
5/15/2020 12:28:57 pm
Thanks Richard - it is the 2019 Edition. I was just curious if it being typically dry changes the material requirements at all.
Reply
Leave a Reply. |
Free SignupSubscribe and learn something new each day:
CommunityThank You to Our Top
October '20 Contributors!
Your PostThe ToolkitSprinkler Designer or Engineer?
Get all of our tools, including the Sprinkler Database, Friction Loss Calculator, Fire Pump Analyzer and more: Filters
All
Archives
January 2021
Daily
Daily discussions are open-ended fire protection, fire alarm, and life safety questions submitted anonymously for the benefit of sharing expertise and learning from other perspectives. Anyone can submit a question here:
Exam Prep2020 PE Prep Guide
(Available Now!) PE Prep Series
(Available Now!) 2020 PE Prep Series
Current Leaderboard (Click to enlarge) PE Problems
Visit July-October for daily Fire Protection PE Exam sample questions.
Solutions are posted the day after posting. Comment with your solutions, questions or clarifications. Please note that questions posted are unofficial and in accordance with NCEES rules are intended to be similar to actual exam questions, not actual exam questions themselves. |