Topic: Fire Protection Systems

“Research: the distance between an idea and its realization” – David Sarnoff, Pioneer of American radio and television

This was the quote used by Rodger Reiswig of JCI last week in his keynote to kick off the Detection portion of the 18th Annual SupDet program hosted by the Fire Protection Research Foundation in Atlanta, GA.  The Fire Protection Research Foundation hosts a technical conference held annually called “SupDet”, which focuses on specific research applications in the Suppression (hence “Sup”), and Detection (“Det”) industries. Mr. Reiswig continued to highlight the impact research has made in the in the fire protection industry. This year, the detection portion of the conference focused on research in several critical areas including detection and signaling for First Responders, Residential Spaces, Wildfire and Smart Technology Systems. Maria Marks, of Siemens, and Jason Webb, Potter Electric Signals, presented on Fire Prevention and Code Compliance in the Age of Information and Automation. As the Internet of Things and the Cloud continue to evolve, the Maria and Jason discussed the impact to life safety systems. Their passion was evident as they described the methods in which systems are being monitored, inspected, and tested, via unmanned equipment such as drones, and robots, as well as handheld devices such as tablets and smartphones. Maria and Jason further explained the benefits and concerns associated with such tasks and even went into how specific NFPA codes and standards (provided below) address automated inspection, testing, and maintenance. NFPA 13, Standard for the Installation of Sprinkler Systems NFPA 14, Standard for the Installation for Standpipe and Hose Systems NFPA 20, Standard for the Installation of Stationary Fire Pumps for Fire Protection NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems NFPA 72, National Fire Alarm and Signaling Code ® NFPA 915, Standard for Remote Inspections (proposed standard) If you missed SupDet, the slides from the presentations will be posted shortly on the SupDet website!
Man looking at tablet and working with a piping system

Weekly or Monthly No Flow (Churn) Tests of Fire Pumps

Fire pumps are an essential part of many water-based fire protection systems. They are used to increase the pressure (measured in psi or bar) of a water source when that source pressure is not adequate for the system it’s supplying. The right design, installation, and acceptance testing of these pumps will ensure that they are ready and available to protect the building on the day of the acceptance test. After that, once “the keys” are handed over to the building owner, there is no guarantee that the pump will remain in a ready state to work as designed unless it undergoes routine inspection, testing, and maintenance (ITM). The requirements for ITM of fire pumps are found in NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems. &nbspWhile there is a good deal that goes into a robust ITM program for fire pumps, this blog will focus on the no-flow test of fire pumps which is often referred to as a churn test. See this blog for weekly fire pump inspections. What is the purpose of the no-flow test? NFPA LiNK where hot spots can be chosen to find more information about certain inspection and testing requirements for different components. How often is a no-flow test required? The no-flow (churn) test of fire pumps must be conducted at either a weekly or monthly basis. The frequency varies by the type of fire pump; diesel and electric; and both have allowances to extend the time between tests based on approved risk analysis.  Generally, diesel fire pumps must be no-flow (churn) tested on a weekly basis. The requirements for electric fire pumps vary. Most electric fire pumps can be no-flow (churn) tested at a monthly frequency. Electric fire pumps which (1) serve fire protection systems in buildings that are beyond the pumping capacity of the fire department, (2) have limited service controllers, (3) are vertical turbine fire pumps, or (4) those taking suction from ground level tanks or a water source that does not provide sufficient pressure to be of material value without the pump all require no-flow (churn) tests at a weekly frequency unless they are provided with a redundant fire pump. Starting The no-flow (churn) test needs to be conducted by starting the pump automatically. The pump must be started by drawing water from the sensing line to simulate a pressure drop in the system rather than using the “start” button on the front panel of the fire pump controller. An allowance is included in NFPA 25 for an automatic timer using either a solenoid valve drain on the pressure control line for a pressure-actuated controller or another means for a non-pressure-actuated controllers. Run time Electric pumps must be run for a minimum of 10 minutes while diesel pumps must be run for a minimum of 30 minutes. Personnel  Qualified personnel must be in attendance whenever the pump is in operation unless automated inspection and testing is performed in accordance with the requirements of NFPA 25. Check out this blog for more on automated and remote inspection and testing. Qualified personnel is defined in NFPA 25 as competent and capable individual(s) having met the requirements and training for a given field acceptable to the AHJ.  Relief valves NFPA 25 allows the circulation relief valve to open to flow water as a cooling measure. Allowing any additional water flow to prevent overheating is not a requirement of the standard. Flow from the circulation relief valve should be sufficient to prevent over-heating of the pump. It should be confirmed that the circulation relief valve is discharging a small flow of water during the no-flow (churn) test. There are additional details around circulation relief valves and main pressure relief valves in NFPA 25 which personnel should familiarize themselves with. Visual observations while pump is not running The following visual observations need to be conducted while the pump is not running. Record the system suction and discharge pressure gauge readings. For pumps that use electronic pressure sensors to control the fire pump operation, record the highest and lowest pressure shown on the fire pump controller event log where such information is available without having to open and energized motor-driven fire pump controller. If the highest or lowest pressure is outside of the expected range, record all information from the event log that helps identify the abnormality. Visual observations or adjustments while pump is running The following visual observations or adjustments need to be conducted while the pump is running. Pump system procedure as follows: Record the pump starting pressure from the pressure switch or pressure transducer Record the system suction and discharge pressure gauge readings Adjust gland nuts if necessary Inspect the pump packing glands for slight discharge Inspect for unusual noise or vibration Inspect packing boxes, bearings, or pump casing for overheating Record pressure switch or pressure transducer reading and compare to the pump discharge gauge For pumps that use electronic pressure sensors to control the fire pump operation, record the current pressure and the highest and the lowest pressure shown on the fire pump controller event log. For electric motor and radiator cooled diesel pumps, check the circulation relief valve for operation to discharge water Electrical system procedure as follows: Observe the time for motor to accelerate to full speed Record the time controller is on first step (for reduced voltage or reduced current starting) Record the time pump runs after starting (for automatic stop controllers) Diesel Engine system procedure as follows: Observe the time for engine to crank Observe the time for engine to reach running speed Observe the engine oil pressure gauge, speed indicator, water, and oil temperature indicators periodically while engine is running Record any abnormalities Inspect the heat exchanger for cooling waterflow Steam system procedure as follows: Record the steam pressure gauge reading Observe the time for turbine to reach running speed In addition to the above, the discharge temperature of the water must be monitored, and the pump shut down if necessary to prevent exposing the pump and/or driver to excessive temperatures. Where the recorded pressure readings on the discharge and suctions gauges show a difference that is greater than 95 percent of the rated pump pressure, the situation needs to be investigated and corrected. The weekly or monthly no-flow (churn) test is an important part of ensuring that a fire pump can be continually relied upon in the event of a fire. These tests will help to ensure that the pump will start and will not overheat in the event of a fire. At an annual frequency, flow testing will be performed to further verify the complete operating condition of the pump. NFPA has a number of resources related to fire pumps and the ITM required for them. Some of these include NFPA 20 Online Training Series, NFPA 25 Online Training Series, the NFPA 25 Handbook, the Certified Water-Based Systems Professional (CWBSP) credential, and the Certified Water-Based Systems Professional Learning Path among many others.
Fire extinguisher label

Fire Extinguisher Ratings

Fire extinguishers are often the first line of defense when it comes to stopping fires while they are still small. A key component of successfully using an extinguisher is ensuring the type of extinguisher is a match for the type of fire. There is the risk of spreading a fire if you use the wrong extinguisher, this is one of the reasons we only recommend that only those who are trained use extinguishers. This blog addresses how extinguishers are classified to help make the right decision when both installing and using portable fire extinguishers. Extinguishers are given a letter rating and some also have a number designation, which come from being tested to UL 711, Rating and Fire Testing of Fire Extinguishers. The letter on an extinguisher rating corresponds to the type of fire that extinguisher can put out while the number correlates to the extinguishing potential.  Class A Fires    Fires in ordinary combustible materials, such as wood, cloth, paper, rubber, and many plastics.  Class B Fires  Fires in flammable liquids, combustible liquids, petroleum greases, tars, oils, oil-based paints, solvents, lacquers, alcohols, and flammable gases.  Class C Fires  Fires that involve energized electrical equipment.  Class D Fires  Fires in combustible metals, such as magnesium, titanium, zirconium, sodium, lithium, and potassium.   Class K Fires  Fires in cooking appliances that involve combustible cooking media (vegetable or animal oils and fats).   Class A fires Class A fires are those that involve ordinary combustible materials such as wood, cloth, paper, rubber, and many plastics. So, when you see a fire extinguisher with a class A rating then you know it can safely put out a fire made of ordinary combustibles. This then leads to the question, well, what size fire extinguisher do I need. Class A fire extinguishers don’t exactly come in sizes, instead they are given a number designation that reflects the extinguishing potential. The higher the number the greater the extinguishing potential. Class A extinguishers need to be able to extinguish varying sizes of wood panels or wooden cribs in order to geta Class A rating. The wooden crib is made of 1 ½ in by 1 ½ in (38 mm by 38 mm) or 1 ½ in by 3 ½ in (38 mm by 89 mm) pieces of dry wood that vary in length depending on the number rating the manufacturer is going for. These pieces of wood are stacked into a crib, lit on fire and if the operator is successful in extinguishing the fire using the portable fire extinguisher, then it gets a certain number as well as the “A” rating. To give you a feeling for what these numbers actually mean; A 3-A rated extinguisher needs to put out a fire made of 144 pieces of 1 ½ in by 1 ½ in by 29 in wood. Class A extinguishers range from 1-A to 40-A Class B fires Extinguishers with a Class B rating are designed to be used on fires that involve flammable liquids and gases (think oil-based paint, alcohol, gasoline etc.). Class B rated extinguishers also have a number associated with them. That number is given to an extinguisher after it has been proven to be able to extinguish a certain size heptane fire. Heptane being one of the main components of gasoline. As an example of what exactly this means. A 10-B rated extinguisher has to be able to put out a fire consisting of 31 gallons of heptane in a 25 ft2 square steel pan. Class C fires Class C rated extinguishers can put out fires that involve energized electrical equipment. There are no numerical components for Class C ratings of extinguishers, we only care about the conductivity of the fire extinguisher. Basically, are you at risk of being shocked when using this extinguisher on energized equipment. To get the C rating the extinguishers are tested to see if any electrical current flows through them as they are discharged on energized electrical equipment. You won’t see an extinguisher with only a C rating, they will always have an A and/or B rating as well. (When electrical equipment is de-energized, extinguishers rated for Class A or B fires are used.) Class D fires Fires that involve combustible metals, such as magnesium, sodium, lithium, and potassium. There are no numbers associated with the Class D ratings of extinguishers. Extinguishers and agents for use on combustible metals fires are rated for the amount of agent and the method of application needed to control the fire. Class K fires Class K extinguishers are used on fires that involve cooking appliances that use cooking oils and fats (think deep fat fryer). There are no numerical components for Class K ratings because they are only tested on a single size fire source. This is tested by lighting a deep fat fryer fire and extinguishing it without any splashing of the oil or reignition. Fire extinguishers often can come with a combination of ratings, for example it’s pretty common to see an ABC rated fire extinguisher that is ok to use on ordinary combustibles, flammable liquids and energized electrical equipment. For more information on requirements related to portable fire extinguishers, check out NFPA 10, Standard for Portable Fire Extinguishers. Also, check out our other fire extinguisher related blogs: Fire Extinguisher Types Fire Extinguisher Placement Guide Fire Extinguisher Inspection Testing and Maintenance
Man inspecting and looking at a tablet

Automated and Remote Inspection and Testing of Water-Based Fire Protection Systems

Remote inspections and automated testing were trends that were gaining momentum in codes and standards and field application for several years. Then in the first half of 2020 when the COVID-19 pandemic was in its early stages and strict lockdowns were being enforced, it pushed this trend to progress even faster as many more realized its potential. During this time, the development of a proposed new standard NFPA 915, Standard on Remote Inspections, continued. While the proposed NFPA 915 will be broadly applicable to any inspection or testing allowed by the AHJ, there are already provisions in NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, that allow for inspections and tests to be conducted in an automated manner. Automated inspection and testing can be a very useful option but what steps must be taken to ensure it is equivalent to a person being at the location? If a fire pump demonstrates an abnormal condition during a test what must the response be and how is the condition corrected? Let’s take a look at the requirements in NFPA 25 to allow the use of technology for automated inspection and testing and the criteria to ensure it meets the same objectives as when they are conducted in person. The first thing to address is when and where automated inspection and testing can be utilized. NFPA 25 does not limit the use provided automated inspection equipment can meet the intent of a required visual inspection and automated testing equipment can produce the same action as required by the testing requirements. Beyond that there are a few other criteria specific to when automated inspection and testing is utilized such as where automated tests do not discharge water that at least once every 3 years the discharge must be visually observed. At that point it becomes a cost-benefit analysis for the stakeholders and primarily the building owner. Activities required at greater frequencies might present more of a benefit while those required less frequently might see less of a benefit. Let’s review the requirements specific to automated and remote inspections. To start, automated test devices must be listed for the purpose of the test being conducted if they are subjected to system pressure or are integral to the operation of the system during a fire event. The equipment must be such that its failure does not impair the operation of the system unless that failure can be indicated by a supervisory signal to the fire alarm system. Similarly, any failure of a component or system to pass an automated test must result in an audible supervisory signal and failure of automated inspection and testing equipment must result in a trouble signal. The monitoring and signals required ensure that instances where there are issues with the automated testing or inspection equipment or an unsatisfactory inspection or test result notification will be made and the situation can be remedied. The testing frequencies of NFPA 25 must be maintained regardless of the functionality of automated testing equipment and a record of all inspection and testing must be maintained in accordance with the requirements that apply to all inspection and testing. One of the benefits of automated inspection and testing is that there is not necessarily a need for personnel on site. However, certain circumstances might need to be addressed quickly. This is specified for no-flow testing of fire pumps. This testing is required on a weekly or monthly basis depending on the type of pump and the building it is located in.  The 2020 edition of NFPA 25 requires that when remotely monitored automated testing of the no-flow fire pump test is being performed qualified personnel must be able to respond to an abnormal condition within 5 minutes. In all reality, this means that a qualified person must be located on site. For the proposed 2023 edition which will be approved this summer that timeframe is to be changed to 4 hours. This additional time means that someone does not need to be immediately on site but can respond quickly enough to take the needed corrective action. The use of technologies to perform automated inspections and testing will only grow in future years. As it becomes more widely used, as building owners, service providers, and AHJs gain more experience, and the use expands into other areas of fire protection and life safety with the future publication of NFPA 915, it is very likely that the requirements will continue evolve
Frozen sprinkler

Dry Sprinklers

Dry sprinklers are a type of sprinkler that are able to extend into a cold space while holding the water back in a space that can be maintained at temperatures where freezing isn’t a concern. Although there are several other methods for installing sprinkler systems in areas subject to freezing, dry sprinklers allow a wet pipe system to be installed while also being able to protect ancillary areas that might be subject to freezing temperatures. Common examples of where you might see dry sprinklers installed include loading bays or balconies that are exposed to the outside ambient temperatures and refrigerated spaces like freezer rooms. Heat transfer basics When thinking about how a dry sprinkler works, we need to consider some heat transfer basics. First, heat always moves from warm to cold and heat transfer occurs in three different ways, conduction, convection and radiation. Below is a brief description of each. Conduction: Conduction is the transfer of energy within a solid, liquid or gas. In terms of dry sprinklers, this is when the cold air in the refrigerated space removes heat from the sprinkler which then removes heat from the piping. This transfer of heat from the sprinkler system into the refrigerated space is what causes the risk of water freezing within the sprinkler piping.    Convection: Convection is the transfer of energy between a solid surface and a moving fluid, such as air and water. This comes into play with sprinkler systems when sprinklers are installed outdoors or in other areas where it can be both cold and windy. Windy conditions increase the rate of heat transfer, meaning that the sprinkler piping looses heat to the outside air more quickly. This starts a chain reaction of heat transfer with the outside air cooling the sprinkler pipe and water inside the pipe located in the heated space loosing heat to the cold sprinkler pipe . If the wind speed increases so much that the sprinkler piping is losing heat faster than the indoor ambient air can provide heat then there is a risk of the water in the pipe freezing.     Radiation: Radiation is the exchange of energy through electromagnetic waves. Think of this as the sun heating up the interior of your car hotter than the outside air. That extra heat comes from radiation. This doesn’t often come into play when dealing with sprinkler systems, but if the sprinklers are in an area heated by the sun during the day, the risk of freezing may increase overnight when the sun goes down. How does a dry sprinkler work? Dry sprinklers work by preventing water from being within the part of the sprinkler piping that will be exposed to cold temperatures. If you are familiar with how a dry fire hydrant works, this is very similar to that.  Dry sprinklers include a portion of piping (often referred to as the barrel) where the water will be sealed off from until the heat element in the sprinkler operated and releases air which in turn releases the seal, allowing water to flow through the orifice of the sprinkler and impact the deflector to discharge on the fire.   Under certain ambient conditions, wet pipe systems having dry sprinklers can freeze due to heat loss by conduction. Therefore, due consideration should be given to the amount of heat maintained in the heated space, the length of the pipe in the heated space, the temperatures anticipated in the non-heated space and other relevant factors. Installation requirements for dry sprinklers Dry sprinklers must be long enough to avoid freezing the water-filled pipes due to conduction along the barrel. To ensure the barrel of the dry sprinkler is long enough NFPA 13 contains the following table in Chapter 15 (2022 edition) which gives the minimum exposed barrel length based off of the temperature that the discharge end of the sprinkler will be exposed to.    Dry sprinkler manufacturers have minimum required lengths to ensure that the dry sprinkler is properly installed and that the point of attachment to the wet pipe sprinkler system will be properly protected against condensation, freezing, and ice plugs. While dry sprinklers are available in many different lengths for various applications where used in conjunction with a wet pipe sprinkler system, care should be taken to ensure that the minimum required lengths are met based on the manufacturer’s recommendations and the expected exposed temperature. For example, in a freezer application, where the branch line can be located directly above the freezer, it might be necessary to elevate the branch line to ensure that the minimum distance is maintained between the cold region and the point of connection to the wet pipe system. It is the length of the barrel exposed to warm air that is important, not the overall length of the dry barrel sprinkler. Ultimately sprinkler systems can be configured in a number of different ways and it is the job of the engineer/designer is to try and make it as efficient as possible. Sometimes this means using dry sprinklers to prevent the water inside of the sprinkler piping from freezing but this isn’t the only method available. Other options include: Dry pipe sprinkler systems, Preaction sprinkler systems, Heat tracing on sprinkler pipe, Listed anti-freeze solution. Whatever method you are using, it is important to understand that there are options out there and that each one of those options has specific design criteria and unique installation requirements that need to be followed to meet the indented objectives. Dry sprinklers may be an effective way of achieving this for ancillary spaces included in a wet pipe system. For more information on the different types of sprinklers, sprinkler systems and other methods for protecting your sprinkler system from freezing check out the following blogs: Options for Installing Sprinklers in Areas Subject to Freezing Types of Sprinkler Systems Types of Sprinklers

Fire Fighter Safety Building Marking Systems

There are two main ways in which fire fighters currently receive information about fire protection features and construction types of a building they are responding to. The first is from a pre-incident plan (see NFPA 1620 for information about pre-incident planning) which is available as a result of prior building inspection and the second is through signage on the building. The most widely adopted signage which most fire fighters are familiar with is the NFPA 704 hazard diamond, which provides information about hazardous materials present and the fire, health, instability and special hazards which they pose. However, there is a lesser-known marking system that has been developed and incorporated in Appendix C of NFPA 1, which if utilized can provide fire fighters the basic information about fire protection features and building construction quickly and concisely as they’re arriving on scene of an emergency. Let’s look at why this type of marking system is important to fire fighters. Modern buildings are designed with fire protection features to protect both occupants and the building itself. Some of these features provide active protection, such as fire suppression systems, while others provide passive protection such as fire resistive construction. The required protection level is dictated by the codes incorporated by reference into law by the authority having jurisdiction at the time the building was designed and constructed, or under a retroactive requirement after the building is occupied. The specific fire protection features in a building, combined with the construction type will play a role in the tactical approaches to suppressing a fire in that building. So, having this information quickly and concisely displayed on the exterior of the building can enhance the fire department’s effectiveness. Although some states have adopted signs identifying construction type and location of truss construction, the fire fighter safety building marking system (FSBMS) in Appendix C of NFPA 1 goes further to include the hazard level of the contents, presence of fire sprinkler and standpipe systems, occupancy and life safety issues and other special designations. What does it look like?   The Maltese cross, which draws its origins from the Knights of Malta, has been widely adopted as a symbol of the fire service. The eight-pointed cross can be easily identified by its curved arcs between the points which all converge on a center circle. The FSBMS utilizes a rating system in each of the arms of the cross and the center circle to concisely display the hazard level, fire suppression systems, occupancy life safety issues and special hazards of a given building. The image above is an example of a FSBMS symbol. These signs should be located “in a position to be plainly legible and visible from the street or road fronting the property or as approved by the fire department.” To aide in visibility the signs should incorporate a white reflective background and black lettering.  Now let’s look at what each of the letters in the four sections of the cross identify. Rating System Construction Type The construction type is identified utilizing letter combinations in the top section of the Maltese cross as follows: FR — Fire-resistive construction NC — Noncombustible construction ORD — Ordinary construction HT — Heavy timber construction C — Combustible construction These construction types provide firefighters a general understanding of how well the building will resist collapse under fire conditions. Fire resistive construction would theoretically resist collapse the longest and combustible construction has the potential for the earliest collapse. Hazards of Contents The hazard of the building’s contents as it relates to fire conditions will be displayed on the left section of the Maltese cross as follows: L — Low hazard. Low hazard contents shall be classified as those of such low combustibility that no self-propagating fire therein can occur. M — Moderate hazard. Moderate hazard contents shall be classified as those that are likely to burn with moderate rapidity or to give off a considerable volume of smoke. H — High hazard. High hazard contents shall be classified as those that are likely to burn with extreme rapidity or from which explosions are likely. The hazard level will provide fire fighters with a general idea of how rapidly a fire will grow and spread through the building contents. This information can be used to anticipate the amount of water and firefighting resources needed to effectively control the fire. Automatic Fire Sprinkler and Standpipe System The presence of automatic fire sprinklers and standpipe systems will be displayed in the right section of the cross as follows: A — Automatic fire sprinkler system installed throughout P — Partial automatic fire sprinkler system or other suppression system installed S — Standpipe system installed N — None The general understanding of what active fire suppression systems are located in the building will guide firefighter’s tactics including apparatus positioning and hose line selection. Occupancy/Life Safety Issues The occupancy and life safety issues will be displayed in the lower section of the cross as follows: L — Business, industrial, mercantile, residential, and storage occupancies M — Ambulatory health care, assembly, educational, and day care occupancies H — Detention and correction facilities, health care, and board and care occupancies This information about building occupants/occupancy type will allow firefighters to gauge the difficulty in evacuating occupants from the building. The L occupancies representing those where the occupant load is lower, and occupants can most effectively evacuate unassisted. The M is of moderate concern where the occupant load is higher and/or the occupants may need additional assistance due to age or health conditions. The H is of high concern where the occupants may not be able to self-evacuate and considerable resources will be needed to evacuate the building. Special Hazards The center circle has been left empty to allow the inclusion of special hazards or provisions. This may be a location to include such things as truss type construction or even the hazardous materials information for example an NFPA 704 diamond, as long as the provisions for size of 704 are met. Summary Having the information on construction type, hazard level of contents, presence of sprinkler and standpipe systems and occupancy/life safety issues has the potential to enhance the effectiveness of firefighters arriving on scene. These responders would be equipped with the knowledge needed to best address an emergency in the building. States which have incorporated NFPA 1 into law should take the extra step to specifically name Annex C in the incorporating ordinance, thus incorporating a national standard the firefighter safety building marking system into law in their jurisdictions. Unless specifically incorporated by refence the FSBMS in Annex C would be a recommendation rather than a requirement. A national system has the potential to increase firefighter effectiveness while decreasing the number of fire fighter injuries and deaths by providing important information quickly and concisely as they arrive on scene. 
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