I'm looking at a few projects that have fire pumps and above-ground cylindrical storage tanks for fire protection.

Some projects I have seen have recirculation after the fire pump discharge underground and back into the storage tank. Frustrated I can't find much on this in NFPA 22 or elsewhere.

Is this part of a means for freeze-protection, or to keep the water from getting stagnant, or for pump testing (in which case I guess it would have to branch off from the flow meter)?

Or is it likely engineer preference? Is it a military requirement?

Thanks in advance.

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We have a project with a unique strobe situation.

New installation into an existing building, Department of Defense so we're under UFC criteria.

The new fire alarm and mass notification system uses Alert strobes (as is common), but in some portions of the building there are blue security strobes. These are used as a warning with non-classified personnel are in the area.

These blue strobes flash at the same rate as the fire alarm/mass notification strobes, but they are not synchronized. The blue security strobes are manually activated at an attendant's desk.

Is there a requirement to synchronize these different systems, from UFC criteria or elsewhere?

Fundamentally, the strobe synchronization issue and potential epileptic exposure is the same concern whether or not it's a concert, fire alarm system, security or dancing club - I certainly understand that we don't want the hazard from the strobes. I do wonder if any of you have come across this, and/or what your opinion might be to handle the situation.

We're on closeout for the project and there has been explicit requirement to override, synchronize or shutdown either the fire alarm or security strobes.

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We have a military project in the US, so the project is mandated to be compliant with UFC criteria.

We are required to locate an LOC (Local Operating Console) within 200-ft of all portions of a building.

Is exiting the building, and re-entering, to access an LOC permissible? 

If we have exterior-only mechanical rooms, electrical rooms, or maintenance bays (which each only access the outside), then at what point would an LOC be required in each of these spaces?

I'm not trying to be facetious or dramatic, just looking for outside opinion on working through a gray area in my mind.

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We're working on an aircraft hanger with a foam system. I can't quite nail this down, as NFPA 409 and the UFC don't spell this out - do the hangar doors need to be open, or closed, in case of a fire or to test the foam system?

Again, don't see any guidance spelled out in either standard. Thanks in advance.

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We are having problems getting a flowmeter to accurately read the flow rate that matches what we are measuring downstream out through a test header. A reading using calibrated pitot gauges outside at 1,500 gpm, for instance, is showing 1,900 gpm on the flowmeter inside.

Military specifications for the project require that the flowmeter read accurately, and that the system be piped such that flow must go through the flow meter out through the pump test header.

The flowmeter manufacturer has recommended using a stream straightener upstream of the flowmeter to better streamline the flow through the meter and get more accurate readings.

Does anyone know of a stream straightener that could be used in a fire pump test loop arrangement?

I would think it would have to be listed, but that's just a gut feeling. I don't currently know of any listed stream straighteners. We generally need to meet the black and white code and specifications mandates spot-on without any code alternatives, if possible, being that it's a military project. Thanks in advance.

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We have a military project (UFC 3-600-01 and NFPA 101 criteria) with 1/2-hour fire-resistance-rated fire barriers between each sleeping unit.

Each 1/2-hour wall consists of gypsum on each side of a metal-studded wall. The gypsum runs within about an inch of the floor in each room (not touching the floor, intentionally, to avoid soaking up moisture/water) where it has metal stud on the backside. 

Is firestop required along the base of the gypsum to maintain the 1/2-hour rating?

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Can Permatex Form-A-Gasket No. 1 Sealant be used in a fire sprinkler system to seal the pipes and threaded fittings instead of PTFE tape?

Also, if the installer added jute (fiber), is this acceptable?

I do not believe that NFPA 13 or UFC Criteria prohibits this practice, but wanted to ask.

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Are initiation devices (smoke detectors, manual pull stations, duct detectors) required to have individual labels on them showing the device address?

The project in question is military and is also subject to UFC requirements.

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Would appreciate if you guys would weigh in on this disagreement I'm having.

Applicable Codes/Standards:
The project is subject to military code UFC 3-600-01 for Sprinkler Design Area and Design Density. Otherwise, NFPA 13-2016 applies to all other aspects of the system fire sprinkler design.

Description of System:
The system consists of a 1,000 sqft Ordinary Hazard Design area, surrounded by a larger (remainder of building) Light Hazard design area (these adjacent hazards are separated by full height walls that are capable of preventing a fire on one side from fusing sprinklers on the other side). Per UFC, the corresponding discharge densities should be 0.20 gpm/sqft over 2,500 sqft for the Ordinary Hazard design area, and 0.10 gpm/sqft over 1,500 sqft for the Light Hazard Design Area.

In accordance with the example provided in NFPA 13 Section A11.1.2, the size of the operating area for hydraulic calculations is determined by the Occupancy of the larger surrounding area. In this case, the hydraulic calculation design area is 1,500 sqft based on the larger surrounding light hazard area. A 0.20 gpm/sqft density would be provided for the 1,000 ft2 Ordinary Hazard design area, with a 0.10 gpm/sqft density for the remaining area.

Differing Opinions:
The difference in opinions for this situation is about how to apply NFPA 13-2016 section 23.4.4.2.5 to this situation.

NFPA 13-2016 23.4.4.2.5 Where the total design discharge from these operating sprinklers is less than the minimum required discharge determined by multiplying the required design density times the required minimum design area, an additional flow shall be added at the point of connection of the branch line to the cross main furthest from the source to increase the overall demand, not including hose stream allowance, to the minimum required discharge.

Opinion #1:
The required minimum design area as referenced in 23.4.4.2.5 should be the SAME design area that was utilized for the hydraulic calculations as determined by NFPA 13 Section 11.2.1. In this case the minimum design area would be 1,500 sqft.

Opinion #2:
Even though the remote area size was determined to be 1,500 sqft per section 11.2.1, the required minimum design area as referenced in 23.4.4.2.5 should be the minimum design area for the smaller, higher hazard area. In this case, the minimum design area should be 2,500 sqft based on the Ordinary Hazard design requirements. So if the flow from the 1,500 sqft hydraulic calculation is less than 500 gpm (2,500 sqft x 0.20 gpm/sqft), then an additional flow will need to be added to the remote area to bring the flow up to 500 gpm.

Which of the opinions do you feel is appropriate for this scenario?

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This building is an H-1 occupancy. There is an area of refuge on the 4th floor. The shelter-in-place Class 3 area of refuge is protected from interior and exterior hazards. There are vertical openings through all 4 floors. The UFC is governing.

Based on this, do the stairwells need to be intertied directly to the shelter-in-place area of refuge for an exit enclosure that is a direct accessible means of egress (we are providing accessibility provisions)? Does the shelter-in-place area need to be a smoke enclosure as well as the interconnected stairwell system?

Based on this will both the stairwell and the shelter-in-place need to be pressurized to meet design intent?

Both exterior and interior air is hazardous and a scrubber would be needed to inject air for stairwell pressurization.

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I am dealing with a Military building. It is an H-1 occupancy. The building is currently 4 stories high.

This is not allowed per IBC based on means of egress.

Has anyone made an argument based on UFC referring to NFPA 101 for means of egress related items to make an H-1 occupancy allowed to be more than 1 story?

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For a flight simulator inside a larger building, what sprinkler density do you feel would be appropriate for this hazard?

The simulator will be its own contained unit, so the top will likely shield water spray from sprinklers above and prevent water penetration to the inside, much like a vehicle fire would in a parking garage.

NFPA 13 does not address simulators, nor does UFC 3-600-01 or FM Data Sheets (as far as I can tell). In my opinion the closest hazard I can gather would be vehicles in a parking garage which carry an Ordinary Hazard Group 1 designation under NFPA 13 (2016) 5.3.1 and A.5.3.1.

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