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.

​​​​​​​​​​​​​​​​​​​​​​Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe

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?

​​​​​​​​​​​​​​​​​​​​​Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe

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.

​​​​​​​​​​​​​​​​Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe

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.

​​​​​​​​​​​​​​​​​​​Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe

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?

​​​​​​​​​​Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe

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.

​​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe

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?

​​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe

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.

Posted anonymously for discussion. Discuss this | Submit a Question | Subscribe