How do we best learn design, installation and inspection techniques? Repeated exposure to projects, designs, or input from others. In next week's post we'll debut our first Design Challenge, where we'll reveal a small portion of a building with details. Sprinkler designers (of any age and any location) can propose how he or she would design the system for the proposed building. Now, here's where installers, plan reviewers and inspectors come in - We'll then take the top few submissions and post them against each other in the following week for a full-on debate about the pros and cons of each submission. After a vote, the creator of the winning design will be revealed and featured on our site. Step 1: Next Week: Building Area Revealed & Design Submissions Accepted Step 2: Following Week: Design Submissions Posted, Debate Ensues & Votes Tallied Step 3: Winner Revealed Are you the hotshot designer? Are you the experienced installer? Are you interested in what frustrates plan reviewers or inspectors? Look for our post next week when we reveal the first Design Challenge.
Backflow preventers are included in fire sprinkler systems to protect public health from contamination by preventing water flow back into the public water grid. In an opposite manner, the forward-flow test for backflow preventers was created to ensure the sprinkler system can be served by enough water in a fire condition. Backflow preventers (double check or reduced pressure zone) type have potential to fail closed where not exercised over long periods of time. Reduced pressure zone backflow preventers are particularly susceptible with the potential for development of closed memory in their spring mechanisms. Reduced Pressure Zone type backflow preventers are especially important to exercise spring mechanisms to ensure full forward flow will be available in a fire condition (Ames/Watts 4000SS Model Shown) The Test Requirement NFPA 25 (2002 Edition Section 12.6.2.1, 2008-2014 Section 13.6.2.1, 2017 Section 13.7.2.1) requires annual testing of the backflow preventer at the designated system flow rate, including hose demand, where hydrants or inside hose stations are located downstream of the backflow preventer. Where a means is not provided at maximum demand, test shall be conducted at the maximum flow rate possible (NFPA 25 20002 Edition Section 12.6.2.2.1, 2008-2011 Section 13.6.2.2, 2014 Section 13.6.3, 2017 Section 13.7.2.3). Section of interior of Double Check Backflow Preventer (single tube style shown from Ames/Watts 757 Model) The Design Requirement While testing can be conducted at the maximum attainable flow the system will allow, the system must be designed with a means of conducting this test. In my experience this is one of the most often overlooked requirements within fire sprinkler system design. NFPA 13 now requires a way to test the forward flow downstream of all backflow prevention valves at a minimum flow rate of the system demand including hose allowances (2013 Section 7.6.3.2.1, 2016 Section 8.17.4.5.1). Editions of NFPA 13 before 2013 simply stated that the backflow prevention assembly shall be forward flow tested (2002 Section 16.2.5.1, 2007-2011 Section 10.10.2.5.1). Design Solutions to Accomplish the Forward Flow Test Option 1: Use the Annual Pump Test and Header (When a Fire Pump is Present) Perhaps the easiest option to conduct this test is to use a fire pump's test header to flow water out of the building. If the backflow preventer is installed on the service/suction side of the fire pump, then a separate forward flow test is not even required as the annual fire pump test already causes the backflow to be tested (NFPA 25 2002 Section 12.6.2.1.4, 2008-2011 Section 13.6.2.1.4, 2014 Section 13.6.2.1.2, 2017 Section 13.7.2.1.2). However, if the backflow is on the system/discharge side of the fire pump, then running a feed with a normally-closed valve to the fire pump test header allows the test header to serve both the annual fire pump test or the forward-flow backflow test. Option 2: Bypass the Fire Department Check Valve NFPA 13 (2016 A.8.17.4.5.1) poses one option to achieve a means for this test with the use of a bypass around the check valve serving the fire department connection. This bypass would need to include a supervised indicating valve that is normally in the closed position. Option 2: Provide a bypass around the check valve serving the fire sprinkler system with a supervised, normally-closed valve to enable forward flow tests out the fire department connection. Providing a bypass around the check valve enables flow to be run out the fire department connection. This works well to take water outside the building and can be directed with testing hoses, however, care should be taken to address clappers inside the fire department connection when they are provided. Some clappers may be removed and replaced in the field to allow a full flow, while others may be directed to allow flow through one side of the fire department connection. Depending upon the system design, this may be a fairly easy method to meet the requirement. Option 3: Provide Hose Connections for Testing If a riser has exterior access, another method of allowing testing of the backflow would be to provided hose valves on the riser itself. Hose connections could be made onto the valves and run to the exterior of the building for the test. Typically, each 2-1/2 outlet should be able to provide 250 gallons per minute of flow. Small low-hazard systems might only require two hose connections to enable this method. Option 3: Provide hose connections on the system riser itself allows hoses to be attached and run out of the building. Option 4: Size the Main Drain to Handle the Forward Backflow Test NFPA 13 suggests that upsizing the main drain would provide a means to conduct the backflow test (2016 Section A.8.16.2.4.2). Depending upon the hazard of the system, this may result in a significantly larger opening in the exterior wall for drainage and for most systems would certainly be larger than a typically large 2-inch main drain. I can't imagine many architects like the look of a large downspout nozzle on the building, but it could be much more sightly than several of the other options listed. Option 5: Install a Designated Backflow Test Header One clear option that is always available is using a designated test header specifically for the forward flow test. Just like a fire pump test header, this would result in a through-penetration to the exterior where water can be clearly directed. Signage is important for any exterior testing equipment to clearly differentiate itself from fire department connections. Option 5: Perhaps the cleanest option, run a dedicated test header to the exterior of the building for the backflow preventer achieves the intent of the forward backflow test Option 6: Use Standpipe Hose Connections (where provided) Lastly, where standpipe hose connections are already available in the building, these outlets could provide enough flow to test the backflow preventer. This test could be the most difficult to achieve, however, as doing so would require a coordinated effort with multiple hoses in different locations to flow outside the building. Option 6: Using standpipe hose connections is a built-in way to run the forward flow test for backflow preventers, but requires multiple hoses and a coordinated effort for testing Summary The forward flow test for backflow preventers is one of the most commonly overlooked requirement for fire sprinkler systems which could impact the actual performance of fire sprinkler systems. Solutions, while cost impacting, exist and are readily achievable to meet the requirement. Interested in more articles like this? Subscribe for free here. More Information NFPA 13: Standard for the Installation of Sprinkler System, 2013. National Fire Protection Association, 2002-2016 Editions. NFPA 25: Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection, 2002-2017. National Fire Protection Association, 2002-2017 Editions. Trieber, Bob. “Forward Flow Testing of Backflow Devices.” SQ, no. 4, ser. 2010, July 2010, pp. 11–12. 2010, doi:01/10/18. We are excited to bring in the new year with some big plans for 2018. This week we're quickly recapping the most-read articles over the past 12 months: A couple years ago I led a university engineering course covering Fire Protection Engineering. While the students consisted of both undergraduates and a couple graduate students, we had one working professional audit the course whom I had worked with on several projects. He was a respected local plan reviewer who had nearly three decades of fire service and review experience. We carpooled to campus before and after each class and had great discussions on the profession, the course, and nuances of private versus public experiences. One week he told me that he was very surprised by the class. Not by the content, but that the engineering students didn’t just already know the concepts we were teaching. It wasn’t that he thought the group wasn’t intelligent, he just always carried the premise that engineers knew all the important concepts that non-engineers don't. The realization he had after a few weeks was that each student was starting from scratch just as he had done years ago. The concept surprised me. While there exists a small handful of fire protection programs in the U.S., the far majority of people who work in and around the industry do not have formal degrees in fire protection. Even for those people, the most important knowledge gained is learned on the job. The premise drives at the point that the greatest benefit to education, at least in engineering, is gathering the ability to think critically and establish a platform for lifetime learning and growth. Recent graduates, even out of the best programs, are nowhere near the same people they become 5, 10, or 15 years later. Education isn't about the content, it's learning how to learn. Those that don't embrace lifelong learning get passed by those who do. Degrees (and education) matter, but a degree in fire protection and/or engineering does not inherently translate to knowledge or a successful career. There is so much great information out there; much of which is more accessible now than ever before. Just about everything I gained during an architectural engineering undergraduate program concerning fire protection was in self-study or through internship experience. Would an architectural engineering program have set me up for long-term success in fire protection? Absolutely; I have no doubt it would have. The many people I’ve encountered from that program (University of Kansas Alumni) or other nearby engineering programs have already proven that it doesn’t take a fire protection degree to do extremely well in this industry. Conversely, I later studied Fire Protection through the University of Maryland a Master of Engineering graduate program. Was is all that it was cracked up to be? In my opinion: yes and more. I learned to think about fire protection as a complete entity and not just within the context of fire alarm and fire sprinklers. I developed roots in performance-based design, began to consider special challenges of nuclear power generation or marine suppression systems, and experienced a depth in content that I had not known existed. Those two programs have impacted my life dramatically. Yet, the most important takeaway I have from each of those experiences is the ability think critically and have a fanatical willingness to continue learning. I read recently that more content is published online in every two days than had been created in all of human history through the twentieth century. There is so much great content in fire protection that exists in printed books, in reports, in training programs, in committee discussions, or is between the ears of that colleague in the office. Knowledge is not limited to formal education – and formal education is not a pre-requisite to be a contributing and success story in this industry. While it might be easy for engineering graduates to say that education isn’t critical to success, I readily believe that the most important and productive learning we can gather is in non-stop reading and intentional question asking. There is so much to learn. Want more like this? Subscribe to these free articles here. Not all code revisions are more conservative. The 2018 Edition of NFPA 101 has updated the long-held occupant load factor of 100 sqft per person to 150 sqft per person. If you don’t live in the life safety arena, this change allows the calculated occupant load for a business space to be notably less, thereby requiring less exit width, stair width, potentially the number of exits, and other means of egress requirements. Origins The 1934 Building Exit Code first incorporated the density of 100 sqft per person, which was based upon a 1922 recommendation from the Building Exit code committee. It has since carried through over eight decades of code revisions and has lasted through many differences in office design. Concentrated Business Use Introduced in 2015 The Life Safety Code introduced the Occupant Load Factor for “Concentrated Business Use” at 50 sqft per person in the 2015 Edition. The goal with determining occupant loads has always been to provide the means of egress for a maximum probable number of occupants, and the introduced higher density was intended to address higher-density spaces than would normally be expected in a business occupancy. Annex material in NFPA 101 states that this should be applied where occupant concentrations are maximized, such as business call centers, trading floors, or data processing centers. Modern open office concepts have changed the way we congregate and occupy buildings Challenges with High Occupant Loads This 2015 Edition change, according to testimony in committee hearings for 2018, has brought increased scrutiny and sometimes higher occupant loads to business occupancies by review authorities. Increased occupant loads impact egress capacity, additional exiting, and can be very difficult to achieve higher occupant loads in existing buildings. Without additional horizontal exiting or plumbing fixtures, many existing office buildings cannot accommodate redesigns under higher occupant loads. Open office concepts have also introduced new challenges. Collaborative spaces are sometimes being reviewed as assembly, even though these small rooms are intended and often used by the same people that are no longer at their workstations. The occupant load could effectively double-count the same occupant for two different work areas. While terminology for the collaboration rooms is not entirely defined, modern office buildings are often labeling these as huddle rooms, quiet rooms, focus rooms, enclave rooms, or other owner-specific terms. These type spaces appear to meet the intent for the new collaborative room load factors identified below. Collaboration rooms, often labeled as huddle, quiet, focus, or enclave rooms, are often used for smaller group activities by people who otherwise occupy the open office space. These smaller spaces function differently than traditional conference rooms. Researching New Load Factors The NFPA Fire Protection Research Foundation sought to study the appropriateness of the business occupant load factor for modern buildings in 2012. Two studies stemmed from their initiative; a WPI Student Research project studies office building designs, modern changes in the workplace, and occupancy impacts of flexible employee scheduling and telecommuting. This study suggested it would be reasonable to increase the load factor to 150 sqft per person. The second study, by Gilbert Group at the University of Canterbury in Spain, found average load factors for modern office buildings averaged 181 sqft per person. Both studies summarized that the 100 sqft per person occupant load was considered conservative. Further testimony in the committee hearings suggested that at least ten research studies on office buildings conducted since 1935 have indicated that the Occupant Load Factor for businesses was conservative at 100 sqft per person. Resulting Changes The research, motions, and resulting voting brought a few major changes to the 2018 Edition of NFPA 101. Business use occupant load factor has increased from 100 sqft to 150 sqft per person; the “Concentrated Business Use” load factor has remained from the 2015 edition; and lastly small collaboration rooms and large collaboration rooms (with a threshold at 450 sqft) are given occupant load factors of 30 sqft and 15 sqft per person, respectively: NFPA 101 Updates to Business Occupancies by Year Relevant Notes While the discussion above considers the process for NFPA 101 Changes, the International Building Code has similar provisions for the 2018 Edition for Business Occupant Load Factors as well as definitions of net and gross floor areas (Table 1004.1.2 and Chapter 2 Definitions, respectively). Lastly, occupant loads of 50 people or more in a single space would still consider the space to be assembly and not a business occupancy. Large presentation rooms, training areas, or lecture halls can quickly introduce assembly occupancy requirements that are unaffected by these changes. Subscribe Find this article helpful? Subscribe for free or forward to a friend. Roughly 160 years ago the development of the industrial revolution brought together people and production into a far greater density than had ever been experienced in history. What was once individual merchants and small productions gave way to the centralized factory. With it came new and larger fire hazards not realized before. Early Manual Systems Early attempts at suppression for fires in these environments (other than manual intervention by responders) included manual piped systems, which fed water to different zones of a building and ended with permeated pipes. These crude systems still required intervention to activate, only provided water after fire had grown, and had issues with plug-holing due to rust or debris in the pipe network. The next iterations involved coating the pipe with tar that melted in a fire, opening holes in pipe that allowed water to arrive near where it was needed. The delivery of water in the manual system was still delayed, and a remaining issue remained concerning water distribution. Parmelee's Automatic Sprinkler Cue the automatic fire sprinkler, the first modern version of which Henry S. Parmelee famously developed in 1878. The new sprinkler featured a solder-sealed cap between water-filled pipe and a perforated shell, which could more precisely relate to temperature. Grinnell's Sprinkler The initial sprinkler still delayed in activation as the soldered element was subject to conduction with cool water from the system and a thermal lag from the brass shell. This was improved upon by Frederick Grinnell, who incorporated a soldered element which was not subject to pressures from the water, was exposed to the temperature of the room (removing the thermal lag), and had a a toothed deflector that better distributed water. Early fire sprinklers often had small deflectors, allowing uprights to direct more spray at ceilings which were often combustible. Over half a century later with manufacturing developments and continued innovation, storage application sprinklers like the Control Mode and then Early Suppression Fast Response were brought to market. The Impact What interests me about the early development was that we were somewhat destined to end up with fire sprinklers constructed in the way we do now. The fire sprinkler is a reliable mechanical device with far greater precision and reliability than nearly all of the public seems to know. It operates independently, simply, and reliably. Despite so many years between the original sprinklers and now, the principles and basic premises are very nearly what was dreamed about by early innovators. I wonder if in those early years they had any concept of the impact or number of lives those basic devices would save. Get more like this by subscribing to these free weekly articles. Know a colleague might be interested? Send to a friend. We prefer wet-pipe sprinkler systems over dry-pipe systems for a handful of reasons: lower cost, no pipe slope requirements, potentially less points of drainage, can locate inspection & testing at the riser, less maintenance, testing and inspection requirements, no power needs, less noisy, and much less potential for corrosion. However, when dry systems are needed, there's several issues to consider for the end-user. Noise Complaints For owners who are not associated with the intricacies of design and maintenance of dry systems, the most frequent compliant we hear about is with the noise associated with the dry system air compressors. Leaky Systems Dry-pipe systems are fed with pressurized air by a compressor. The compressor run-time frequency and duration is directly attributed to the amount of leakage in the system. Some people directly attribute the leakage of the system to the quality of installation due to the final tightness of fittings. Air injected into a leaky system develops two problems. The first is increased potential for corrosion as fresh air naturally contains water moisture and oxygen, the two ingredients for corrosion. Air that feels comfortable to us offers sufficient products to encourage corrosion, and leaky systems tend to fail with corrosive issues much earlier in their lifetime. The second issue is noise. While it sounds trivial, noise isn't for the employee whose cubicle is next to the riser room. If leaky systems cause issues, why don't contractors prevent or fix leaky systems? Fixing Leaky Systems Once a system is installed and pressure tested to meet minimum standards, finding points of leakage is very tedious and time consuming. Just finding a few leaky fittings requires inspecting every joint and adjusting connection points. Needless to say, if a system isn't installed with tight fittings it becomes a very time-intensive and costly proposition to fix. Lessening Leakage and Noise in Design As a designer I naturally have less impact on the quality of installation than I do of the design, and there are several ways to help lessen the impact of leakage and noise. Leakage requirements could be mandated to be leak less than prescribed code minimums. I've found this route doesn't exactly make good friends of contractors. Noise can be reduced in a number of ways. First is to use tank-mounted air compressors in lieu of riser-mounted air compressors. Tanks act as a pressurized reserve, where they can reduce the frequency which compressors run in order to supply the system. Mounting to the tank also vibrates the tank, and not the piping network that runs through a building. Vibration on the pipe network requires absorption by the building, which contributes to higher ambient noise. The base of the tank can be isolated with vibration isolation (often rubber pads), again helping to reduce vibration transmission to the building. The downside to tank-mounted compressors is an increased cost and needs for additional floor space. Another important consideration is where the compressor is located. Often the allotted space for risers are determined architecturally, but upfront coordination and planning to help prevent locating dry riser rooms next to normally occupied spaces can have major benefits. If the dry riser room must be near occupied spaces, consider requesting insulation within walls or acoustic panels to help absorb sound. Quiet-Series Air Compressors Lastly, one of my favorite products to hit the market in the last couple years offers a major solution to the noise issue. I'll start by saying I don't have any family or friends that work for General Air Products. They have not reached out to me to offer any money (although if you're out there General Air I'd be happy to share an address for a check). That disclaimer aside I really love the Q-Series (Quiet Series) General Air Compressors for fire sprinkler systems. The Q-Series air compressor model can be tank-mounted and is significantly quieter than standard air compressors. The noise for the Q-Series have reduced noise by 20 dBA from the previous 80 dBA of standard oil-less compressors. For drywalled, carpeted rooms the effective sound from the Q-Series compressor is only slightly higher than ambient noise levels of a typical office. The video above (by General Air) shows the difference in compressor noise. Needless to say it would be great for applications in hospitals, schools, offices, hotels, retail, nursing homes, and other areas sensitive to noise. We've found these to be a great solution to a common and intrusive issue of noise with dry risers near occupied spaces. Is this article helpful? Consider subscribing to these weekly articles or sharing it with a colleague who might benefit. If you haven't felt that tinge of anxiousness in the air, then you probably aren't spending time near someone taking the 2017 PE Exam. This Friday over 200 professionals throughout the world will sit for the eight-hour Fire Protection P.E. Exam. It's a recognized mark of competency and for those taking the exam, a major milestone in his or her career. In May of this year we published the 2017 MeyerFire PE Prep Guide, which introduced over 100 new questions, additional tips and references, and major revisions to the 2016 Guide. It was nothing short of a monstrous effort to compile the new 376-page volume. In addition, in June we launched a 20-week Weekly Exam Series in an effort to provide more practice while simulating actual exam conditions. This was joined by our continued free Daily PE Problems throughout the summer. While this year was a big step up in involvement, it also was a very positive experience. We have had probably our most involved group of test takers to date, both in the number of questions posed, comments on the daily problems, and lively discussions in the PE Prep Facebook Group. A handful of last year's examinees provided real-time feedback in the Facebook discussions and a couple helped us compile new daily problems for this year. There have been some learning curves on my end that cropped up this summer - namely needing better editing on my part as we had (in my opinion) too many errata updates to the 376-page guide. We will be incorporating all of those updates in the 2018 Guide. Another improvement I'm wanting for 2018 is to open up my availability late in the fall (September & October) better one-on-one help. I'll be exploring ways to better share and discuss content between now and next summer in that regard. This summer I have again been impressed by how hard and thorough so many test takers are in their preparation. We've had some of the most in-depth content discussions around prep material of any summer to date. It seems as though the more problems and content we're able to distribute, the more discussion and depth everyone is able to soak up. It's certainly a good thing from a learning perspective. For those taking the exam this week, remember that each year there's always some subject that appears completely out of nowhere. Just remember that those are just as surprising to everyone else taking the exam, and, some of those questions may not even be scored but rather trial questions for future exams. Do your best and forget the rest.
For those not taking the exam but know someone that is, give him or her a hug. Or don't, because that creeps people out - but do encourage beforehand and help celebrate with them afterwards. It's a big effort and for many an anxious time, but can be just as rewarding as well. Showcase your job opportunity to our active community of fire protection professionals (designers, engineers, inspectors, review authorities, and more). Our emails are read over 3,000 times monthly, and our site regularly brings over 35,000 page views each month (38,485 in August and 40,693 in September), all reaching professionals in the fire protection industry. This offers a great opportunity to reach a tremendous audience with your job opportunity. We're excited about this new outlet where we hope to serve both job hunters and suppliers. As a launch offer, the first 15 subscribers who checkout using coupon code JOBS2017 will get a free listing. Post your job opportunity and find more information here. You can also see all job listings with us here: Job Board. I grabbed something different this week and revisited the classic Fahrenheit 451 by Ray Bradbury. If you have not read the short fiction, it is centered around Guy Montag, a fireman in the near future who ignites rather than fight fires. His dystopian world is governed by invasive mass media and a real fear for independent ideas and thought. People have little time or regard for each other or any thirst for knowledge, rather preferring information that are “digest of digests”, compoundings of simple summaries so vanilla and basic as to not offend any for feeling unintelligent. While we don’t live in the exact environment Bradbury describes, there are parallels to our current day. Ever passed someone with a cell phone that wouldn’t recognize your existence? Ever get the impression like mass media is invasive, or a source of constant noise? Fire in the novel is the tool by which this dystopian society denounces and discredits individual thought, effectively censoring anything that could be considered contrary to public needs. The title gets its name from the autoignition temperature of a book (although we know now that books self-ignite at ranges of temperatures which are dependent upon the materials). Besides using fire as a theme throughout the novel to describe the pains of censorship, I find the biggest parallel to our industry is concept of individual knowledge growth. Knowledge or true independent thought cannot be gained simply by asking "how". Rather, it can be far more important to ask "why?". We live by standards. In fire protection, especially in the United States, we are constantly in the realm of prescriptive code requirements whose rules we commit to memory and treat in high regard. But why are those rules in place? It is not enough to simply know how plans are arranged, systems are installed, or how inspections are conducted. Our value as an expert is all about understanding the why, or the importance and implications behind the rules. What is the good of experience if you've never stopped to ask why? I have experienced several times in group or teaching environments where where learners want to know the how but not the why. How to lay out sprinklers with a given obstruction? How to layout fire alarm appliances for a movie theater? How to orient branch piping for a dry system in a parking garage? As a teacher it can be easy to deliver the how and provide a solution. But how much is lost in the opportunity to learn and teach in that moment? We fail our understudies if we don't provide ample reasoning as to why decisions are made or solutions are suggested. Our goal is to develop knowledgeable thought leaders, not machines that duplicate past work. As a learner it can be all too easy and tempting to find short term solutions without digging deeper. In the design and construction industries, time can be our most valuable asset which does not lend itself to long duration of self study. In order to make our experience translate to wisdom, we must ask why. Good engineering judgement, often related to experience (but not necessarily a guarantee from it) is built upon a constant thirst for learning and growth. That thirst may be what brought you here. I won’t even pretend to say that I’ve captured the why behind such a deep and varied engineering discipline like fire protection. It will be many years and many challenges before I will begin to scrape the surface of understanding much of the why behind our profession. But I will make the most of that journey by asking why. |
ALL-ACCESSSUBSCRIBEGet Free Articles via Email:
+ Get calculators, tools, resources and articles
+ Get our PDF Flowchart for Canopy & Overhang Requirements instantly + No spam
+ Unsubscribe anytime AUTHORJoe Meyer, PE, is a Fire Protection Engineer out of St. Louis, Missouri who writes & develops resources for Fire Protection Professionals. See bio here: About FILTERS
All
ARCHIVES
June 2024
|