Second Valve Required on a Fire Service Main?

6/7/2023

I'm working with a city inspector who is adamant that we add a second non-rising stem valve (NRS) in the fire sprinkler service main just before the building. The first valve being in the street at the live-tap location with the roadway box.

Is a valve required on the service main before the building?

The requested location would place the valve under the sidewalk, accessible by T-handle wrench only, prohibiting reliable supervision of any kind.

I can't seem to find any language in NFPA 24 that I can use to argue against the second unsupervised valve. I don't see any value in the position the inspector has taken and requested a copy of the city ordinance requiring the additional valve.

Installing the second valve wouldn't be a huge deal but certainly seems like an unnecessary opportunity for an unsupervised valve to get closed or fail. I would like to hear what others in this community think and if anyone has something to offer.

Thanks in advance.

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13 Comments

Pete H

6/7/2023 06:37:10 am

This sounds like it could be a local ordinance requirement. I can't think of any code that would require additional control between the riser inside the building and the curb box valve

6/7/2023 08:15:57 am

Try NFPA 24 §6.6.1, it provides direction when sectional control valves are needed. It is based on the number of fire protection connections - 6. This includes hydrants, lead-ins, risers, etc.

This requirement may be requested due to the number of fire protection connections b/w the point of connection and lead-in.

Glenn Berger

6/7/2023 08:25:57 am

If the city inspector requires it, you will need to check the city regulations to validate.

Be careful of a Catch-22 condition - PIV distance from the building in accordance with NFPA 24.

6/7/2023 08:34:17 am

A valve is required. All criteria for compliance must be met for whichever valve assembly is chosen.

NFPA 24:6.2.9 All connections to private fire service mains for fire protection systems shall be arranged in accordance with one of the following so that they can be isolated:
(1)*A post indicator valve installed not less than 40 ft (12 m)
from the building
(a) For buildings less than 40 ft (12 m) in height, a post
indicator valve shall be permitted to be installed
closer than 40 ft (12 m) but at least as far from the
building as the height of the wall facing the post indicator valve.
(2) A wall post indicator valve
(3) An indicating valve in a pit, installed in accordance with Section 6.4
(4)*A backflow preventer with at least one indicating valve not
less than 40 ft (12 m) from the building
(a) For buildings less than 40 ft (12 m) in height, a backflow
preventer with at least one indicating valve shall
be permitted to be installed closer than 40 ft (12 m)
but at least as far from the building as the height of
the wall facing the backflow preventer.
(5)*A nonindicating valve, such as an underground gate valve
with an approved roadway box, complete with T-wrench,
located not less than 40 ft (12 m) from the building
(a) For buildings less than 40 ft (12 m) in height, a nonindicating
valve, such as an underground gate valve
with an approved roadway box, complete with
T-wrench, shall be permitted to be installed closer
than 40 ft (12 m) but at least as far from the building
as the height of the wall facing the non-indicating
valve.
(6) Control valves installed in a fire-rated room accessible
from the exterior
(7) Control valves in a fire-rated stair enclosure accessible
from the exterior as permitted by the AHJ

Brett

6/7/2023 08:44:21 am

If none of the requirements listed by "JH" apply, then ask the inspector to provide the code citation he is using to make his request.

SCHULMAN

6/7/2023 09:45:52 am

Required here ... usually satisfied by the Backflow Preventer

Jon

6/7/2023 09:58:27 am

The leading cause of sprinkler "failures" is a closed valve. The more valves on a system (either interior or exterior), the greater chance that one could be closed - whether intentional, inadvertent, neglected, or forgotten.

Yes; the city utility often requires a shut-off for various legitimate reasons (broken pipe, water supply maintenance, non-payment, etc.) but not sure that a second shut-off gains anything.

More is not always better when it comes to fire protection systems.

Alex

6/12/2023 06:44:42 am

Late to the game here. I agree with Jon. I would verify with the city ordinances but would avoid adding the valve if possible.

Eric R

6/7/2023 12:46:11 pm

I wonder if this is maybe a regional thing, but from my experience there is always a secondary underground valve on the private property for underground lines.

In my area the valve that is directly at the tapping saddle on the primary street main is owned by the water purveyor, and we are strictly not allowed to touch these valves as a private contractor. Then a second underground valve is installed on the feed once it crosses onto the private property as the start point of the 'private fire service main'. We are allowed to touch this valve in case repair work is needed on the private line.

Personally I think this valve is important to have as it allows for repair/replacement of the first aboveground control valve, or the backflow preventer. Both of which generally need servicing before to long.

It does add an extra valve that needs to be inspected/tested, but is not required to be monitored since it is below grade and can only be accessed with a special tool.

NFPA-25 could probably more clear about the specific testing requirements for curb valves, but FM Gobal inspections do require that the valve be physically tested to confirm full open monthly, and fully exercised yearly.

Casey Milhorn

6/12/2023 02:43:00 pm

Late in responding to this one, but JH has the correct section cited. I'm pretty sure NFPA 24 used to say (in order of preference, or something along those lines but not anymore). Technically you only need ONE valve per NFPA and it can be anyone of those listed (with the exception of additional valves for sqft limitations and sectional control valve requirmements). This could be the tapping valve at the street, a property line valve, a PIV outside, a Wall PIV, a valve on the riser without direct outside access, etc.... BUT a lot of AHJs do have a preference on what they prefer or require. As others have stated, the least amount of valves the better (especially unsupervised ones). Typically the water department is going to get whatever they want (1 valve or 10 valves) up the property line. The AHJ (fire marshal or codes) can ask for whatever they want after the property line and inside the building, BUT you may want to ask for the amended code or reference on where they are getting that from to cover your tail.
My personal feelings on valves are:

1. The fewer the better
2. First choice is a remote PIV away from the building (for protection of the fire fighters)
3. Second choice is a wall PIV
4. Third choice is a riser room with direct outside access
3. Supervised remotely whenever possible and avoid additional UG NRS gate valves.

Todd Delisle

6/14/2023 08:24:39 am

I've had projects for MIT that have required this; Cambridge (MA) Water Department:

Please Note: CWD requires a permanently installed valve, acceptable to the fire sprinkler design engineer of record, inside the building and just upstream of the backflow device. This valve allows for the efficient removal of the backflow device, for any reason, without the need to shut the service off at the water main in the street.

It is published on their website for "Conditions for Approval" and was cited at the time plans were being developed. Nice that they provided narrative for reasoning.

A little different with the valve being inside the building where it was afforded a tamper and low pressure switch if I recall correctly.

Dave Auman

7/31/2024 11:16:53 am

We have a Fire Main that has a valve off the water main. From there it feeds three buildings. Two of which have an isolation valve. The third is a new building and they don't want to put in an isolation valve outside the building before the backflow. so, if there is any issue with the #1 valve on the backflow, we will have to stop water to two other buildings. Is this ok

Jack G

1/16/2025 10:28:33 am

I agree with Todd/Casey.
Usually not permitted to touch the street valve if a second valve is furnished , wall post or post indicator, or another valve/ curb box and key the street can be isolated if the back flow “ assembly “ needs replacing.

Second Valve Required on a Fire Service Main?

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