From a sprinkler contractor in the UK - We have a British Standard BS 9251 which is based (loosely) on your NFPA 13 D/R for the use in houses, flats and care homes and so on. One area which is very grey to us and not included in the design standard is the distance from obstructions such a pendant lampshade which lower than the ceiling or a smoke detector or emergency light fitting.
I know most contractors are using 300mm (1 ft) as a minimum from a pendant drop light fitting but then you ask them why no one can tell you. for other obstruction such as a smoke detector many any using 4 times the depth as a method. For beams and larger continuous obstructions, it's much easier as most just use a bean rule in EN BS 12845 (our equivalent NFPA 13). I would be very interested in understanding the approach which you take for such things and very much looking forward to your assistance. Posted anonymously by a member for discussion. Discuss this | Subscribe.
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Had a quick question regarding design of thrust blocks for underground FDC / fire water supply. In your experience is that design typically a civil designer’s responsibility or the responsibility of the fire sprinkler sub?
I have a project where both parties are saying they do not do this design – the sprinkler sub says their design begins at the flanges in the riser room. I have an earthwork subcontractor doing the physical installation of the FDC and fire water pipes outside leading into the riser room. Would thrust blocking details then need to be calc’ed and detailed by the civil engineer? I’d appreciate knowing what your experience has been! Posted anonymously by a member for discussion. Discuss this | Subscribe. I've come across several retail projects where there will be a "closet" that is just solid shelves about 18-24 inches deep and about four or five shelves tall, with a mirror across the front that acts as a door. It's certainly possible to provide a sprinkler outside of the closet and protect to the back of the hazard, but is this approach allowed?
To me it doesn't seem practical to provide a sprinkler at the top inside this shallow unit just as we wouldn't provide a sprinkler within the inside of cabinetry. If anything, the multiple solid shelves could prevent heat from collecting at the top and water from effectively reaching the bottom, although the door could also prevent discharge from reaching the bottom. Curious how others would approach these situations. Posted anonymously by a member for discussion. Discuss this | Subscribe. I've had the request multiple times from architects to provide closely spaced sprinklers near interior windows to provide the equivalent of a 1-hour wall.
The only support I see for such an arrangement in the International Building Code or in NFPA 13 for glass is specific to the "Enclosure of Atriums," Section 404.5 (2003-2009 Editions) or 404.6 (2013-2015 Editions). If someone is looking to provide the equivalent of a 1-hour wall, with glass, that is not a part of an atrium enclosure, then are the only options to provide rated glass or the Tyco WS Window Sprinkler? I sense a lot of confusion on this topic from architects, whom I guess see other project arrangements and just assume they're standard closely-spaced sprinklers. Posted anonymously by a member for discussion. Discuss this | Subscribe. Is a sprinkler ever not required in an electrical room? We typically provide sprinklers in all electrical rooms, but are being asked specifically if we can omit one on a project.
Posted anonymously by a member for discussion. Discuss this | Subscribe. A foam system is being used to protect for spilled methanol within a dike of a tank 1,120 square meters (12,055 sqft). What foam proportion would be recommended?
Is there an advantage between a balance pressure pump proportioning system or an in-line balance pressure pump proportioning system? The system is being designed under NFPA 11, 16, and 30. Posted anonymously by a member for discussion. Discuss this | Subscribe. If a glass face of a shower door goes up adjacent to the ceiling (and the bathroom is not excluded from sprinkler protection based on size) then would the shower itself need sprinkler protection?
Based on the proximity of the shower's glass door to the ceiling it looks like it would be a floor mounted obstruction, per NFPA 13. Posted anonymously by a member for discussion. Discuss this | Subscribe. Have a project that requires the sprinkler system to be zoned by the areas with active smoke control. Each floor of the highrise is approximately 12,000 sqft is to be divided into two zones. I intend to have multiple floor control risers (valve, check valve, flow switch, pressure gauge, inspector's test & drain) for each smoke control zone. Is there any less costly way of accomplishing this?
It has been suggested that multiple flow switches can be placed on the same system with different retard settings so that the fire alarm system can identify where the water is flowing, but I don't have experience with this option. Posted anonymously by a member for discussion. Discuss this | Subscribe. I have a question regarding performing or checking hydraulic calcs for a pressure tank supplied system in a retrofit application.
As an example, suppose our system is located 5 floors below the existing pressure tank for a high rise building in New York City (NYC). The tank was designed and installed under prior codes and utilized the pipe schedule methods. We may have 2 tanks connected that are 9,000 total gallons capacity each with 1/3 air and 2/3 water pressurized at 75 psi (the initial pressure) at the tank. Our connection to the sprinkler riser being 5 floors down now has 75 psi plus the pressure gained by gravity (5 psi per floor typical NYC arrangement) equaling 100 psi static available. The jurisdiction now requires all systems to be hydraulically calculated. The calculation are done to the point of connection to the riser and not all the way back to the water source (NYC quirk) and no hose demand. The contractor provides a calculation stating that the system demand is below the 100 psi (95 psi residual) and less than 400 gpm (light hazard occupancy 30 minute supply), and claims it works. We’ve argued that as the tank drains, the air-to-water ratio changes, therefore the pressure available at the end of the 30 minutes is not the same as initial tank pressure. Using the formula given in the Annex of NFPA 13, we can solve for what a system demand should be given the existing initial conditions of the tank plus the pressure gained by gravity and say that as long as the calculated system is less than that pressure, the system is acceptable. But is that a correct assumption? I want to give them all the correct procedure, methodology and theories behind this subject. Posted anonymously by a member for discussion. Discuss this | Subscribe. A project that has evidence storage will have a new fire sprinkler system. The storage is anticipated to be solid back-to-back shelves no more than about 8 feet in height, but will hold crime evidence which could and will likely include firearms. What sprinkler design density is required for this area?
Posted anonymously by a member for discussion. Discuss this | Subscribe. A retrofit project has very low floor-to-floor heights where we need to install floor control assemblies within the stairwells. Is there a minimum "head height" for the pipe that it needs to be installed above the floor if the pipe isn't against a wall?
Posted anonymously by a member for discussion. Discuss this | Subscribe. When are pressure relief valves required for fire pumps, and what is their intended purpose? There's a wide variety of pump arrangements and many don't include pressure relief valves.
Posted anonymously by a member for discussion. Discuss this here. We're in the process of reviewing our specifications against industry markers and I'm interested in comparing major differences in owner-driven specifications (not NFPA, FM, XL GAPS, or other insurance standards). What clients do others work with that they find represent good practice for the industry?
Posted anonymously by a member for discussion. Discuss this here. Have a project which requires very tight coordination between sprinkler and ductwork. The ductwork will be lined with insulation which could come in contact with the black steel fire sprinkler pipe. Is there a minimum clearance required that wouldn't permit this contact by code?
Posted anonymously by a member for discussion. Discuss this here. Where can I find presentations or references on the differences between NFPA 13-2016 and 2019 editions?
Posted anonymously by a member for discussion. Discuss this here. A Level 2 Aerosol is to be boxed and stored on pallets at 15 feet with a ceiling height of 26 feet. Which of the following sprinkler protection criteria is acceptable? a. Standard Spray (K-factor at least 8.0) Sprinklers; 0.30 gpm/sqft over 2,500 sqft b. ESFR upright K14.0, quick-response, 12 sprinklers at 50 psi c. ESFR pendent K16.8, quick response, 12 sprinklers at 35 psi d. ESFR pendent K22.4, standard response, 12 sprinklers at 25 psi Solution | Posted 09/05/18
Determine the flow (in gpm) through an extended coverage pendent K16.8 sprinkler at 85 psi. a. 52 gpm b. 155 gpm c. 348 gpm d. 1428 gpm Solution | Posted 09/03/18
Daily Discussion question submitted from a member:
Small bathrooms can omit a sprinkler under NFPA 13 in some instances where bathroom walls and ceilings (including behind the shower and tub) are non-combustible or limited combustible with a 15-minute thermal barrier rating (NFPA 13 2002 814.8.1.1, 2007-2016 8.15.8.1.1). If the bathroom has a window to the exterior, would it need a sprinkler? Discuss this here. Had an experienced fire sprinkler contractor run a flow test in a semi-remote area (outside of a large metro area) with a higher residual pressure (45 psi) than static (42 psi). The static pressure was confirmed both before and after the flow test. The flow was relatively low (410 gpm using a 1-3/4" pitoless little hose monster).
I've yet to come across a scenario like this before - could this be due to the city's pumps kicking on during the test, or something else? Wondering if anyone had experience in this regard before. Note: This is a Daily Discussion question submitted anonymously to us by a toolkit member. See the discussion here. For open-web steel joists systems I commonly see sprinkler hanger attachments to the top of the structural joists. When would it be permissible to attached to the bottom of the structural joist?
Note: This is a Daily Discussion question submitted anonymously to us by a toolkit member. What is the difference between cast iron and ductile iron fittings? Is there a preference between the two for use in sprinkler or clean agent system fittings?
Note: This is a Daily Discussion question submitted anonymously to us by a toolkit member. An existing high-rise hotel project in central Florida has open exterior exit stairs. By code and local ordinances, standpipe hose connections are required to be in the stair (hose connections on the corridor next to the stair are not allowed).
Since the project is located in central Florida (with lowest one-day mean temperatures between 25-30 degrees F, according to Figure A.10.4.2(b) of NFPA 13-2016), is there any way to still use wet standpipes and route them in the stair? Doing so could involve enclosing the standpipe perhaps in a small shaft and keeping the hoses in insulated cabinets. Or in this case is the best option just to have the standpipe be dry to completely avoid any freeze potential? Note: This is a Daily Discussion question submitted anonymously to us by a toolkit member. Discuss This Here. Sprinklers in indoor handball & racket ball courts. Any known exceptions for sprinkler coverage? Appreciate any available insights.
If no exceptions exist, what have others done to avoid interference with the playing areas? Note: This is a Daily Discussion question submitted anonymously to us by a toolkit member. Discuss This Here. I'm currently working on a project for a packaging factory in which there are rooms which are used for storage of Milk and Juice in stainless steel tanks that are about 1.5 m (4.9 ft) in diameter and 8 m (26.2 ft) in height.
There are about 5-6 tanks for each area (milk and juice storage). Each room is about 70 sq.m. (753.4 sqft). The ceiling height is about 11.1 m (36.4 ft). The content combustibility (i.e. Milk & juice) is low and the quantity is high. Since the height of the tanks is above the threshold of 3.7 m (12 ft), I cannot consider it to be protected by LH or OH1 curves and it should come under storage occupancy and commodity classes. Since my exact requirement is not present in the list of commodity classes in NFPA 13, I figured it to be Class 1 per the liquid content. Accordingly, it would be under Commodity Class 1 curve in NFPA Chapter 14 Figure 14.2.4.1 (2013 Edition) and multiplication factor for density vs storage height from Figure 14.2.4.3. Kindly let me know if I'm on the right track or if there is something which I overlooked. Note: This is a Daily Discussion question submitted anonymously to us by a Toolkit member. Discuss This Here. What methods have you found to be successful to reduce the noise and frequency of air compressors for dry and preaction systems?
Note: This is a Daily Discussion question submitted anonymously to us. Submit a Question or Discuss This Here. |
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