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Many sprinkler systems in our area (I'm a fire marshal) have aboveground pipe installed by a fire sprinkler installer and the underground installed by an underground pipe contractor. NFPA 24 requires a minimum flow rate from underground pipe in order to remove rock and debris from the underground pipe.
Many of the underground contractors simply open up the pipe and wait until there's consistent clear water and/or stop hearing the rocks ping around. There's no measurements taken for the underground flushing and when I ask for them to verify the flow rate I get blank stares. Is there a way to tell just by static pressure in the area if opening up the pipe flange is enough flow to satisfy the underground flushing? Or is there a measurement I should be seeing to verify the flow rate? Thanks in advance. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe
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A horizontal split-case electric fire pump is serving a seven story high rise with modifications on the upper level. If the pump is rated for 68 psi at 750 gpm (58 brake hp) and keeps a constant impeller diameter, what will the new brake horsepower be if the speed is increased from 1790 rpm to 1850 rpm? a. 56 hp b. 60 hp c. 62 hp d. 64 hp Solution | Posted 08/03/20
E&O insurance; Many recognized brand names cover fire sprinkler layout, which is a re-branding of basic liability coverage for sprinkler installation contractors. The same policies will in most cases cover fire protection engineering design in instances of design-build contracts.
Does anyone know of a good underwriter of E&O policies exclusively for Fire Protection Engineering? One that is affordable, and also has a good claims payment history, S&P rating? Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe An equivalency is being developed for a building with unprotected steel W24x76 columns. Determine the fire endurance time (in minutes) for one of these columns W24x76 columns have an approximate flange and web thickness of 0.68 inches, and a flange width of 8.99 inches. a. 4.3 minutes b. 7.8 minutes c. 9.7 minutes d. 55.3 minutes Solution | Posted 07/31/20
We're designing a fire sprinkler system for plastic (Group A material, unexpanded polyethylene) recycling site. We are designing only for the depot area. There are raw materials stored as solid blocks up to ...We've raw material stored as solid blocks up to 12 feet (3.6 meters).
I am thinking this should be considered rack storage under NFPA 13 Section 16.2.1.2 (2016 Edition) for Protection Criteria for Rack Storage of Class I Through Class IV Commodities Stored Up to 12-ft (3.7m) in Height. Am I wrong considering this? Note that compacted material will have a lower combustion propagation velocity than generic goods. Any ideas? Thanks in advance. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe Determine the response time index (in ft^1/2 s^1/2) for a 160-degree F heat detector with a listed spacing of 30 feet. a. 44 b. 80 c. 169 d. 180 Solution | Posted 07/30/20
We have a new 3,300 square foot dental facility that is single story with a basement. Is a fire sprinkler system required?
Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe Annual inspection of wet barrel hydrants must include all of the following except: a. verify marking of hydrant b. verify outlet thread condition c. verify access to hydrant d. verify cracks in hydrant barrel Solution | Posted 07/29/20
NFPA 13 (2010 Edition) 21.23 Cleanrooms: 21.23.1.1 Automatic sprinklers for cleanrooms or clean zones shall be hydraulically designed for a density of .20 gpm/sqft over a design area of 3000 sqft.We have a wet pipe system utilizing quick-response sprinklers.
With an ordinary hazard density (.20 gpm/sqft) would I be allowed to use the quick-response design area reduction in Chapter 11? Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe Which of the following extinguishers would not be suitable for a fire containing oil-based paints, solvents, alcohols, and lacquers? a. AFFF b. carbon dioxide c. potassium chloride d. wet chemical Solution | Posted 07/28/20
This week is the eighth of our 2020 PE Prep Series - it's 20-weeks worth of mini Fire Protection PE Exams. Each week we'll post the leaderboard here with the results of that week's exams. To see full leadership board and more details, visit the PE Prep Series page here.  The Leaderboard lists the top total scores for the most recent three weekly exams for PE Prep Series participants. See the entire scoreboard here.  Want to join in? It's not too late - the PE Prep Series is the ultimate PE Prep tool. It's a series of 1-hour, 10-question simulated PE Exams offered weekly with solutions immediately following each exam. Learn more here. Every week of the series is retroactive so you can still test yourself with past week exams.
I need an answer for a simple question. I am working on a large airport project expansion. I have a structure of 4 levels with 70+ sprinkler zones.
Is there an NFPA standard requirement stating that each area requires a hydraulic calculation on each system? Each system is not prototypical. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe A chemical processing plant has an explosive release in one of the mixing areas, causing a fireball that at 16 meters and a radial distance of 24 meters causes a radiant heat exposure of 6.2 (kW/sq.m.)^4/3-min. What is the expected burn effect for workers with exposed skin? a. Minor irritation b. 1st Degree burn / severe skin pain c. 2nd Degree burn d. 3rd degree (full thickness) burn Solution | Posted 07/27/20
Good morning, I have a project with a 60MVA outdoor transformer. We have a deluge valve system with wet pilot trim.
Is there a standard requirement for protecting the transformer regarding k-factor, coverage area, and distances for a sprinkler/nozzle from the transformer? Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe Of the following substances, which would have the greatest total heat output for the same amount of mass? a. ethane b. methanol c. toulene d. acetone Solution | Posted 07/24/20
Does anyone have much experience with fire pins/plugs as part of a fire door?
I came across some during a project to replace fire doors. There's a male and female component but ultimately a pin/plug is released at high temperature and goes into a hole to secure a pair of fire rated double doors. My question is: are the pins just a substitute for a lower latch or is there some special code or regulatory driver for them? Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe The essence of the fire process is an exothermic reaction which releases heat and other products. Oxidation which takes place with reactants in the gas phase, as opposed to the solids phase, results primarily in what kind of combustion? a. flaming b. smoldering c. detonation d. backdraft Solution | Posted 07/23/20
I have a question that stems from NFPA 318 (Protection of Semiconductor Fabrication Facilities), Chapter 11, Section 11.1.4.2.
11.1.4.2* Automatic sprinklers for cleanrooms or clean zones shall be installed in accordance with NFPA 13, and shall be hydraulically designed for a density of 8.15 L/min·m2 (0.20 gpm/ft2) over a design area of 278.8 m2 (3000 ft2). For a clean room 11.1.4.2 mentions 0.20 gpm/sqft density over 3,000 sqft design area. We're considering quick-response standard-spray sprinkler coverage under section 11.1.4.4. The client is requiring a double-interlock pre-action system, so under NFPA 13 11.2.3.2.5 the remote area must be increased by 30% without revising the density. Can we omit the 30% increase in sprinkler operation under NFPA 13 11.2.3.2.3 since we are using quick response sprinklers? Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe A building addition is to connect two existing buildings of different construction types. Which of the following construction type arrangements is always permissible? a. Provide the least fire-resistive construction type of the connected portions with no fire barrier separation b. Provide 1-hour vertically aligned fire wall is installed between them to create separate buildings c. Provide any construction type for the connection portion with 2-hour fire barrier between buildings d. none of the above Solution | Posted 07/22/20
I’m working in the construction of 4-star hotel. The water storage tank is underground made from concrete and the pump room is located above the water tank. The designer specified the fire pumps to be vertical split-case type! In order to follow code, I proposed to install vertical turbine pumps instead of the specified vertical-split case.
The supervisor Engineer is insisting to follow the specification of the fire pump and pushing me to create an underground pump room in order to install the specified pump set. Any recommendations to avoid this directive? I have a bad flooding experiences with this this type of subgrade pump rooms. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe A stair is being designed as pressurized as part of a smoke control plan. A single door gap below a 4 foot wide door has a 0.35 inch tall door gap where the pressure differential between the two sides of the door are 0.1 in. w.g.. Assuming a flow coefficient of 0.7 and normal atmospheric conditions, what is the volumetric flow rate of air through the gap? a. 33 cfm b. 73 cfm c. 104 cfm d. 148 cfm Solution | Posted 07/21/20
This week is the seventh of our 2020 PE Prep Series - it's 20-weeks worth of mini Fire Protection PE Exams. Each week we'll post the leaderboard here with the results of that week's exams. To see full leadership board and more details, visit the PE Prep Series page here. Please Note: The solution for Problem #7 of Week 7 used the Total Heat Release Rate to find the height of the flame tip. This is incorrect; the convective portion of the heat release rate (assumed to be 70% of the total heat release rate) should be used to calculate flame tip height. Those who answered "c" have been credited as having this problem correct:  The Leaderboard lists the top total scores for the most recent three weekly exams for PE Prep Series participants. See the entire scoreboard here  Want to join in? It's not too late - the PE Prep Series is the ultimate PE Prep tool. It's a series of 1-hour, 10-question simulated PE Exams offered weekly with solutions immediately following each exam. Learn more here. Every week of the series is retroactive so you can still test yourself with past week exams.
A parking garage has multiple levels covered by a dry system.
If the floor area of each level is equal to 52,000sf, is it acceptable to protect all levels with one dry system riser? I am referencing the NFPA 13-2016 Handbook Sections 8.2 and its accompanying explanations. Thanks. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe At what frequency shall a preaction sprinkler system valve be trip tested with the control valve fully open? a. annually b. every 3 years c. every 5 years d. every 10 years Solution | Posted 07/20/20
I recently investigated some fire doors at one of our older buildings and saw they have an FM Approved label on them instead of a common UL Listing. I'm used to the UL listing label which clearly states the fire rating in minutes or hours. The FM label I saw gives some outdated ASTM standards and references a CABO report but doesn't clearly state the fire rating.
Does anyone have experience with the FM Approved fire door labels? Based on my research, FM stopped approving fire doors a while ago. Thanks in advance. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe |
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