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Is there a recommended maximum distance between the Fire Department Connection (FDC) and check valve?
NFPA 13 does not include a required maximum distance between the check valve and the FDC. I understand the intent is to reduce the length of non-pressurized pipe. My project includes a warehouse with a free-standing FDC located about 125-feet from the building. Is it best to locate the check valve indoors, where it can be easily inspected and maintained, or, located underground, closer to the FDC where it would be buried? Sent in anonymously for discussion. Discuss This | Submit Your Question | Subscribe
15 Comments
matt
3/4/2021 09:14:39 am
I have seen it done both ways. One thing to consider - the buried check valve is only a realistic option if you can access it (without digging).
Rusty Scott
3/4/2021 09:58:50 am
Agree with Matt, the 5yr check valve inspection is required to have access, this can get expensive to create a vault just for this valve, though I believe alot are just buried.
Fouad Dr
3/4/2021 09:22:04 am
I would say keep the CV indoors for ease of maintenance.
CJ Bonczyk
3/4/2021 09:57:52 am
Best to locate the check valve inside for maintenance by the sprinkler contractor or maintenance personnel. Combination vaults are convenient as well depending on the brand. I prefer to keep the water checked off on the inside in the even the check malfunctions so that it can be replaced easier. Also if the check outside fails outside you need to rely on the ball drip to properly drain the residual water in the FDC line (which doesnt always happen if it gets clogged. We commonly place a redundant check inside at the spigot for the FDC even if there is one at the vault so that any residual water drains at the ball drip in the vault or FDC outside and the UG FDC line into the building is dry up to our check inside.
Chad
3/5/2021 10:41:46 am
As an AHJ myself, I have to ask, if the building collapses, what good is the FDC? There are plenty of other reasons for a remote FDC, without a doubt. Did you get a reason from them?
Jerry Flanigan
8/23/2023 04:45:02 pm
I would say it's better if your not in an area that freezes to put the check valve on the remote fdc piping above ground and install the siamese right on top. Makes it much easier to inspect. Very easy to perform forward flushes and you avoid having to dig up anything for inspections.
Curtis Tower
1/9/2025 08:53:46 am
Hey Chad!
Franck
3/4/2021 10:04:48 am
In addition, if you keep your check valve inside (heated building), you reduce the possibility to have frozen portions of your FDC, as only the heated portion of the pipe (downstream the CV) will remain wet.
Mike R
3/4/2021 10:17:57 am
As the others said leave the check inside and the pipe outside to the FDC dry. 3/4/2021 10:28:06 am
The Cleveland (Ohio) Water Department requires that the backflow preventer be located at the street, even though they do not inspection or service that device. As the AHJ, we like this location since we know there is pressurized water all the way to the riser which is verified every year via a forward flow test. If the backflow is located in the building at the riser, the FDC underground piping would only be verified as usable every 5 years during the FDC hydro. On the other hand, the backflow preventer is harder to maintain in the underground vault. And it is harder for the fire protection company to perform the 5 year FDC hydro since they have to disconnect piping in the vault to isolate the FDC. Bottom line, there are positives and negatives to either location for the backflow.
Dave L.
3/4/2021 12:09:10 pm
We spec the check valve to be inside the riser room all the time. And I try to remember to remind Civil to show a ball-drip for the underground, which I have seen accomplished a few different ways. (I've seen ball drips installed in the incorrect orientation too.) The NFPA #13 Annex says to locate the check valve to maximize accessibility and minimize freezing potential. And recommends to "reduce" the length of the non-pressurized line. I have read of concerns about the volume of water that may be emitted for the ball drip, the amount of air that may be pushed into the system, and the that since this line is not monitored, less pipe is better. Certainly valid concerns, yet no maximum length has been established. And I'm not a fan of buried check valves.
Dave L.
3/4/2021 12:12:19 pm
(* when the FDC is not incorporated into the backflow vault assembly and the check valve is located inside the vault.)
MIGUEL D.
3/4/2021 02:18:57 pm
I understand that the empty pipe section between the FDC and the check valve should be protected against corrosion.
Mark S.
3/5/2021 09:19:40 am
The real problem with "dry" underground pipe to the FDC is if it is ever damaged during subsequent excavation (no water leak), the only time you're going to know it is when the fire department hooks up to the FDC and blows it out of the ground!
Cristian H
2/2/2024 08:13:28 am
I agree with Mark. You would also detect an issue during the 5 yr hydrstatic test required for the FDC, but that is only every 5 years. Leave a Reply. |
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