NFPA 11 identifies several materials for foam concentrate pipe & valves, including brass, bronze, stainless steel (304 or 316), or other material in accordance with foam concentrate manufacturer's certification of compatibility with the foam concentrate as approved by the AHJ. [NFPA 11-2016 4.7.1.1]

Can we use hot-dipped carbon steel pipe to meet this requirement after the foam pump to the foam chamber of the cone roof tanks?

The distance is more than a mile long (1.2 miles, 2 km). Thanks in advance.

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

The International Fire Code (IFC) Section 6004 for highly toxic and toxic gases states the following for exhausted enclosures:

6004.1.3(1) The average ventilation velocity at the face of the enclosure shall not be less than 200 feet per minute with not less than 150 feet per minute.

However, in the same section for gas cabinets (Section 6004.1.2(1)), the words "at any point of the access port or window" are added after "150 feet per minute."

Doe anyone know if this was an oversight by the authors of this section? Did they miss a few words in the requirement for exhausted enclosures?

I don't understand why the 150 feet per minute would be for gas cabinets but not exhausted enclosures (albeit without referencing where the 150 feet per minute measurement is to be taken). This issue is coming up at my work as we have several exhausted enclosures and gas cabinets and some of the exhausted enclosures have ports/windows which are sealed shut. Thanks in advance!

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

We're under the International Fire Code, Section 903.2.11.5. This section allows fire sprinklers to be installed in commercial hood/duct systems.

Is this intended to be in the ductwork only, or also protecting the cooking equipment?

I've never seen this before, but it seems to go against everything we're taught about cooking and grease fires (don't put water on them)! Thanks in advance.

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

We are designing a clean agent system for electrical rooms located within a high-rise building. We are proposing having dedicated clean agent releasing control panels for the electrical rooms, and a separate building Fire Alarm Control Panel.

Is it mandatory to connect fire/smoke dampers (and other shutdown devices) in the electrical room with the clean agent releasing panel, or can these be connected to the building fire alarm system?

Thanks in advance.

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

We have been asked if a 20+ year old wet pipe sprinkler system we installed into a paint application room is the correct method of protection for a specific paint product that is currently being used.

The MSDS sheets for a few of the products they now use indicate protection with dry chemical, foam, or water fog.

I have been told that the MSDS sheets typically refer to the product as its being stored and not necessarily as its being applied. The storage is not happening in this room of course, but in approved fire-rated storage cabinets outside the area. None of the typical requirements for alternate protection are met per NFPA 33.

Basically other than the product data sheets, this is a run of the mill paint application area. Nothing automated or fancy.

Anyone have any experience with a similar situation?

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

Do liquid nitrogen storage rooms need to be fire-resistance rated?

According to NFPA 55 (2016 Edition) Section 6.4.4, gas storage rooms need to be 1-hour fire rated, but it just seems odd since nitrogen can be used as an extinguishing agent.

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

Does anyone know of a dry-chemical or equivalent fire suppression system that can be used in cold environments (as low as -20 degrees Fahrenheit)?

The space to be protected is a testing chamber approximately 8 feet by 11 feet (made of combustible materials). Automatic fire extinguishers are not an option as they don't have any UL rating. Thanks in advance.

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

I have a question regarding the need to provide electrical classification for a building using Class 1A flammable liquids.

For this building, 4 gallons could be out in use (located anywhere in the building). The MAQ is 10 gallons. I have discussed this with NFPA 30 committee, the manufacturer, and the AHJ (who is a knowledgeable FPE). They have all determined that even if the MAQ is not exceeded, electrical classification is required if a flammable/explosive mixture could be present.

The NFPA 30 staff directed me to a provision in NFPA 497, Section 5.5, that if the materials will not reach 25% of the lower flammable limit (LFL), this could be utilized to justify not providing classified electrical fixtures.

Does anyone know how to do this calculation, or know of firms that can be hired to do this?

I am an FPE and do not know how to perform it, and I have spoken with other FPE’s who also are not aware. The gentleman I spoke with at NFPA 30 agreed it would be by an industrial hygienist or a chemical engineer and not an FPE.

But does anyone know any that can be hired for a one-off calculation, or have a place where I could learn how to perform it myself (NFPA reference, SFPE article, course, etc.?).

Thank you!

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

Have a project at a local grocery store that has an end cap kiosk with a Class 1 commercial kitchen hood. The kiosk is 6-foot wide by 8-foot long and has one means of egress out of the kiosk. The kiosk is used for cooking demonstrations and to hand out food samples to the customers.

​The predicaments we (AHJ, owner, designer of record, and contractor) are having is the location of the manual release station. There are no structural columns or architectural surfaces that are within the minimum distance of 10 feet or a maximum of 20 feet from the cooking surface to mount the manual release stations that are within the means of egress.

Any thoughts or suggestions on where to mount the manual release station?

Thanks in advance.

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

At our site I'm dealing with personnel wanting to park small vehicles (Gem carts and forklifts) inside the building.

I know this is clearly not allowed in an egress corridor (where it was) but I'm having trouble finding parts of the code addressing storage in mechanical rooms or similar space. I know NFPA 101 has rules for high hazard contents but not sure if I can make that argument for the vehicles.

Any thoughts or suggestions?

Thanks in advance.

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

Has anyone seen the International Fire Code Chapters 53 and 58 applied to natural gas installations in addition to the Fuel Gas Code?

IFC Chapter 53 is Compressed Gasses and Chapter 58 is Flammable Gasses.

It's technically a gas at standard temperature and pressure with a boiling point below 68 deg F at 14.7 psi and flammable range of 5% to 17% by volume in air. Natural gas appears to be subject to these requirements, but I've never seen it this way in practice. 

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

We have scenario where we are using foam system under NFPA 11 for a floating roof tank with Crude Oil.

Based on our previous calculation for a prior tank the fire water demand is 1,926 gpm so we have existing 2,000 gpm pump to be able to supply the required flow. But an additional Crude Oil tank has been added and we have run our new hydraulic calculations and we come up with 4,496 gpm new flow requirement.

Is there a way we can still use the existing fire pump?

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

​Does anyone have experience with a specific fire extinguisher for fires involving platinum catalysts? I know this would generally fall under the Class D type of extinguishers but was wondering if there is a platinum specific extinguisher like there is for lithium fires (lith-x brand). Also, if you do have experience is there any difference in operation besides a regular extinguisher (for example how the agent is propelled)?

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

Per NFPA 17A section 7.2 an owner's inspection is required for a wet chemical extinguishing system. I'm currently in the process of making a checklist for those systems at my site.

7.2.1 On a monthly basis, inspection shall be conducted in accordance with the manufacturer’s listed installation and maintenance manual or the owner’s manual.

However, how often does the "outside world" comply with this requirement?

I know at the previous site I worked at, we admittedly did not. Also, what are the tamper indicators and seals referred to in paragraph 7.2.2?

7.2.2 At a minimum, this “quick check” or inspection shall include verification of the following: ...
(3) The tamper indicators and seals are intact.

Not quite sure I know what NFPA is referring to there. Thanks in advance for all responses!

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

I have an existing foam/water deluge system covering vessels and sprinklers providing area coverage for pool fires. The sprinklers are smaller than K-5.6. The owner wants us to match the existing sprinklers. 

In your opinion, is this acceptable?

For reference, NFPA 13 (2013) Section 8.3.4:
8.3.4 Sprinklers with K-Factors Less than K-5.6 (80).
8.3.4.1 Sprinklers shall have a minimum nominal K-factor of 5.6 (80) unless otherwise permitted by 8.3.4...
8.3.4.2 For light hazard occupancies not requiring as much water as is discharged by a sprinkler with a nominal K-factor of K-5.6 (80) operating at 7 psi (0.5 bar), sprinklers having a smaller orifice shall be permitted, subject to the following restrictions:
(1) The system shall be hydraulically calculated.
(2) Sprinklers with nominal K-factors of less than K-5.6 (80) shall be installed only in wet pipe sprinkler systems or in
accordance with the limitations of 8.3.4.3 or 8.3.4.4.
(3) A listed strainer shall be provided on the supply side of sprinklers with nominal K-factors of less than K-2.8 (40).
8.3.4.3 Sprinklers with nominal K-factors of less than K-5.6 (80) shall be permitted to be installed in conformance with 11.3.2 for protection against exposure fires.
8.3.4.4 Sprinklers with nominal K-factors of K-4.2 (57) shall be permitted to be installed on dry pipe and preaction systems protecting light hazard occupancies where piping is corrosion resistant or internally galvanized.

NFPA 15 (2017) Section 7.3.3. Flammable and Combustible Liquid Pool Fires
Water spray systems designed to control pool fires resulting from a flammable or combustible liquid spill fire shall be designed to apply a net rate of not less than 0.30 gpm/sqft of protected area.

I think my new design will require nozzles spaced at 100 square feet if the k-factor needs to be smaller than k-5.6 under NFPA 13.

Also, do you know of any non-aspirating nozzles that are listed for foam?

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

I had thought the presence of the elevator itself does not necessarily require a sprinkler system if the building does not require a sprinkler system.

For example, if a two-story, type II-B, Business (B) Occupancy building is under 23,000 sqft, the IBC does not require a sprinkler system to be installed. Therefore, the hoistway or the EMR would not require sprinklers.

I’ve had elevator designers argue that the presence of hydraulic fluid requires sprinklers.

I disagree, however; hydraulic fluid is typically a Class III-B flammable liquid. In the example above a two stop elevator would have less than 1000 lb (~150 gal) of hydraulic fluid which does not trigger any Hazardous Occupancy as the control area volume limit for closed-use systems is 13,200 gallons.

Is this the correct approach to take? Does the presence of the hydraulic fluid or any other component of an elevator trigger sprinkler requirements for the rest of the building?

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

Our common CRAC Units (Cooling, Refrigeration and A/C) for data centers only cool the air directly from the data center and back into the data center.

Do these need to be shutdown with the use of a total-flooding clean agent system? 

If the CRAC unit is only exchanging air within the same space then I'm not sure what harm it would do if it's running during or after clean agent discharge. I'm curious if I'm off the mark here, thanks!

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

NFPA 2001 requires a safety factor under sections 5.4.2.3 through 5.4.2.5 for clean agent extinguishing concentrations.

What is the difference between the "design concentration" listed in Table A.5.4.2.2(b) (2015 edition) and this minimum extinguishing concentration (the minimum extinguishing concentration MEC x applied safety factor)?

In some cases the design concentrations are higher than the MEC x safety factor - is there a proper one to be using under NFPA 2001? Sorry if the question is basic - I've always just used the design concentrations.

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

First of all I work at a gas company as a Fire Equipment Maintenance Specialist in Libya. My job is to follow up and assess efficiency of fixed firefighting systems and provide plans for preventative/corrective maintenance/testing based on schedules.

One of our firefighting systems has a foam bladder tank which protects an oil tank and plant operations.

My problem is when we started this project the bladder tank was built out of global standard. The foam concentrate AFFF is stored between the internal tank wall and membrane. Water gets inside the membrane which forces the foam to get out through the rated membrane. 

I know it is wrong and does not produce a perfect foam solution within the specification. When I complained about this case, my manager asked me to provide an opinion based on international standards. 

Is there guidance within NFPA-standards that can help me address this issue?

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

Inergen (IG-541) is being used for protection of several rooms which contain highly valuable historic documents. If the fire type is considered Class A and the design concentration of Inergen is provided, determine the clean agent-air mixture density.
a. 1.15 kg/cu. m
b. 1.25 kg/cu. m
c. 1.28 kg/cu. m
d. 1.44 kg/cu. m

Solution | Posted 09/19/19

Solution | Posted 08/22/19

Once again great info/insight. Though it made me think.

What if you have a type II hood without wet chem protection? Are sprinklers required? I think yes (following obstruction rules).

To take it a step further, what if you have a type I hood with protection over the required appliances including the plenum but not below the plenum in areas where there are ovens/non-cooking equipment? As an AHJ, I have never required additional protection here. But now I question myself.

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

Is there a secondary marketplace for selling halon for a decommissioned system? Where's the best place to start when looking to sell halon tanks?

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

What is the fire protection standard for CT-Scan, PET/CT, tomotherapy, etc. rooms?

NFPA 13 notes only that occupancies shall have automatic fire sprinkler system or an approved alternative.

I have seen double standards in installed systems in one hospital project I worked in wherein the hospital AHJ proposed wet sprinkler system on one occasion while clean agent fire suppression system was used on another.

My concern is that an unconscious patient left inside the gantry by staff in panic can die if the clean agent fire suppression system discharges in the treatment room. Whereas, on another hand, millions worth CT, PET/CT, tomotherapy machines can be seriously damaged beyond repair if the wet sprinkler system works to put out fire inside the room.

It sometimes seems like a choice between protecting patients which is the core business of healthcare facilities or protecting costly property from damage. Is there an absolute standard to put a period to my query? Thanks.

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

​A trench is built to handle overflow of heavy oil from a common garage workspace area to a containment tank. Determine the flame height (in meters) for an open linear fire (130 kW/m) within this trench.
a. 0.44 m
b. 0.87 m
c. 2.2 m
d. 25.7 m

Solution | Posted 07/09/19