Search

Introduction.The problem of timely activation of fire sprinkler systems is highly relevant for effective fire suppression before the critical moment, when calculated values applied to extinguish the fire, become ineffective. A number of works address the problem of effective application of the fire sprinkler system to Class A fires. The application of such methods to Class B fires has not yet been considered.The model simulating a fire in a room with an automatic fire extinguishing system.The response time assessment model, developed by the co-authors for an automatic water-consuming fire sprinkler system, allows to identify the velocity of flame spreading over the surface of an HFL/CL spillage and the temperature rise rate in the ceiling area in the case of a B class fire.A sprinkler is triggered by the bulb bursting caused by the thermal effect produced by the ascending convection flow.A model has been developed to determine the response time of a fire sprinkler system exposed to the effect of a heat flow, caused by the Class B fire, on a heat-sensitive sprinkler bulb.Activation of a fire sprinkler system by the rate-of-rise heat detector.A model, designated for determining the activation time of a rate-of-rise heat detector, was developed.Examples.A number of examples, illustrating the response time of traditional, deluge, and forced launch fire sprinkler systems, are provided in the article.Conclusions.The obtained formula allows to quickly check the applicability of different types of fire sprinkler systems to ensure the effective protection of premises in which class B fires may break out.

Aqueous suppression systems (i.e. fire sprinkler, water mist) have been extensively utilised for compartmental fire suppression due to their significant heat extraction ability. Nevertheless, challenges can be foreseen in suppressing water-reactive chemicals as a violent explosive reaction will be triggered, such as alkali metals (i.e. Na, Li) and alkali metal hydrides (i.e. LiH, LiAlH4). In this study, expandable graphite (EG) is proposed as a potential suppressant against alkaline metal fire due to its advantageous thermal properties and chemical stability. In-house user-defined functions (UDFs) are developed to characterise the particle expansion coupled with the heat and mass transfer process between EG and the fluid mixture. The model is incorporated in the large eddy simulation (LES) framework to study the temporal fire behaviours and the suppression effect of EG against the flame plume. The numerical model was validated by comparison of temperature profiles and expansion rate of EG particles along the suppression event against experimental results. The EG was found to be relatively effective in fire suppression compared to the same amount of natural graphite. Parametric analysis was conducted on a range of EG particle size between 400 µm—1000 µm to investigate the suppression mechanisms and the suppression efficiency of EG particles against metal fires. Within the range of the current study (400 µm—1000 µm), the EG particle diameter of 400 µm has achieved the most effective suppression performance and the suppression time of 2 s. It is observed that the smaller size of EG tends to be effective in fire suppression than the larger sizes.

This paper presents frequency reconfigurability of a microstrip patch antenna using a nickel-titanium (Ni-Ti) shape memory alloy (SMA). It comprises a radiating patch made up of Ni-Ti SMA. It is characterized by differential scanning calorimetry, four-probe method and x-ray diffraction in order to evaluate transformation temperatures, electrical resistivity and different phases present in the material, respectively. Currently, a fire sprinkler system consists of a “wet alloy” which will expand when heated initially and then breaks allowing water to sprinkle onto the fire. The present work uses a two-way Ni-Ti SMA which is used to actuate the fire sprinkler system, triggers a sound alarm and is also able to send a message via SMS to the administrator. A microstrip patch antenna is designed, fabricated and measured for reflection coefficient, radiation pattern, and antenna gain at flat and bent configurations. The antenna operates at 2.4 GHz in the flat condition and 3.8 GHz in the bent configuration. This patch antenna can be used in fire alarms which actuate at 66°C and stop the fire without causing much damage. Unlike a conventional fire alarm system, proposed fire sprinkler designed with a Ni-Ti SMA can be reused several times.

Several Internet of things (IoT) based smoke or fire detection designs have been made in previous research and a study has shown that the IoT system can implement fire sprinklers using a water pump controlled by microcontroller. However, control systems with proven methods such as Fuzzy Inference System (FIS) need to be implemented in the system and evaluated to improve the control system. This research focuses on designing and evaluating a smart fire sprinkler device prototype that can detect and extinguish fires based on the FIS classification and send the information to an android application using IoT. The FIS classification proposed in this study uses Tsukamoto inference based on several inputs taken from three sensors, which are a fire sensor, a temperature sensor, and a smoke sensor. Four fire conditions represent four different levels of sprinkler output: smoke, small fire using burnt straws, medium fire with a candle, and large fire using burnt paper balls. Through testing, the success rate of the system in classifying fire and extinguishing the fire has a macro average F1 score of 90%.

Accurate representation of fire sprinkler spray enables quantitative engineering analysis of fire suppression performance. Increasingly, fire sprinkler systems are evaluated using computer fire models in which sprinkler spray is simulated with Lagrangian particles. However, limited guidance exists as to how to predict the behavior of complex, spatio-stochastic fire sprinkler spray or how to accurately represent the dispersion of spray in terms of Lagrangian particles. The current work predicts the dispersion of the fire sprinkler spray generated by a canonical axisymmetric sprinkler using a Lagrangian particle tracking model within FireFOAM, an open source computational fluid dynamics fire model. In this work, the initial fire sprinkler spray is described with a new spray injection model characterized by a multivariate probability distribution function related to spatially resolved breakup radius, volume flux, drop size, and drop velocity. This function is stochastically sampled to generate Lagrangian particles representative of the near-field spray and the dispersion of these Lagrangian particles is in turn simulated in FireFOAM to predict the far-field spray. Our new model is compared to a baseline FireFOAM spray injection model which incorporated fewer spray details. Modeled results are compared to highly resolved far-field measurements of axisymmetric sprinkler sprays generated by the Spatially-Resolved Spray Scanning System (4S).

Automatic fire sprinklers use a heat sensitive element such as a glass bulb or fusible link to respond to the heat from a fire. The response of commercial fire sprinkler glass bulbs has been extensively characterised in convection-dominated dry gas flows but in real fires there may be more factors that influence the heat transfer to the bulbs such as radiation from the fire or cooling from adjacent sprinkler sprays. The time of activation is the only indication of the thermal response of typical commercial fire sprinklers using glass bulbs to a fire, but direct temperature measurement using a modified proxy may provide a better understanding of how sprinklers respond in a complex environment. Modified glass bulbs have been created that allow a thermocouple to be inserted in the bulb for direct temperature measurement. In this paper, the thermal response of sprinklers with these modified bulbs has been observed in hot-air wind tunnel plunge experiments and full scale room fire experiments. At the time of activation the measured temperature of the modified sprinklers was found to be higher than the nominal activation temperature specification for the unmodified sprinklers. For the compartment fires, a thermal response model generally predicted longer sprinkler activation times based on ceiling jet temperature and velocity measurements than was observed experimentally.

Fire sprinkler manufacturers have developed a great variety of application specific sprinkler designs. Advances in product development practices, performance based design, risk analysis, and fire suppression research have increased stakeholder interest in quantifying the spray produced by these devices. These sprinkler spray patterns consist of complex spatio-stochastic features originating near the sprinkler head. A Spatially-resolved Spray Scanning System (4S) has been developed to capture the complete spatio-stochastic nature of the spray at its point of origin for documentation and analysis. The 4S synthesizes spray measurements, transport analysis, and statistical representation frameworks providing high-fidelity spray characteristics suitable for evaluation of component-level performance (e.g. sprinkler spray pattern uniformity) or system-level performance (e.g. fire suppression system simulations). Each sprinkler's unique spray pattern is captured through optical and mechanical probing of the spray over a measurement (or initialization) surface close to the sprinkler head (0.4−0.8 m) and analyzing local drop characteristics (e.g. drop size, velocity, and volume flux). These high-fidelity 4S spray measurements consisting of terabyte scale data densities present remarkable challenges with regard to data management, test repeatability, and test timing. These challenges are addressed through integration of automation, flow control, data acquisition, and data analysis systems. Spatially-resolved sprinkler spray measurements are presented providing insight into the sprinkler spray patterns and their connection with deflector geometry. Comparisons between far-field spray dispersion measurements and simulations initialized with 4S measurements demonstrate unprecedented agreement further highlighting the value of spatially-resolved sprinkler measurements for modern suppression analysis.

Investigation on Microbial induced corrosion is of importance if it helps in overcoming problems posed by corrosion. It is, therefore, of utmost importance if such type of work can be used in controlling MIC experienced by the construction materials used in various industries or elsewhere. This chapter, therefore, deals with different industries where MIC is observed and pose problems. This chapter discusses about corrosion problems due to MIC in (i) oil and gas industry, (ii) pipeline in petro-chemical plant, (iii) nuclear power plant, (iv) high temperature environment, (v) pipeline and water systems, (vi) fire sprinkler systems, (vii) cooling cycles, (viii) sewage plants, (ix) marine environment and off-shore structure, (x) maritime vehicles, (xi) offshore infrastructure, and (xii) organic fuel.

Fire sprinkler is a safety system that is active when fire is detected. It consists of a bulb that holds the water flow and made of glass with liquid inside. The increase of temperature in its environment would expand the volume of the liquid and break the glass which leads to water spray to extinguish the fire. This study aims to model and simulate the fire sprinkler bulb and optimize several parameters related to its activation including the thickness of the bulb, type of liquid and the ratio of air and liquid inside the bulb. The modeling and simulation was performed in COMSOL Multiphysics with variation of wall thickness and liquid inside the bulb. The result showed that the best parameter was the liquid of glycerol, a height of 17.5 mm and a glass thickness of 0.1 mm, this resulted in the air to liquid ratio of 0.0042428 and breaking time of 7.2400s. This result was the fastest breaking time towards several simulations. For future study, several parameters need to be considered in the simulation to minimize the gap between the simulation and the actual condition, such as room condition, and water pressure.

A Reduced Order Model (ROM) providing a highly detailed description of the sprinkler spray has been developed for engineering applications. The new ROM approach combines an elegantly parameterized analytical description of the dispersed spray with a tightly integrated high-fidelity description of the initial spray capable of producing a complete quantitative map of the entire sprinkler spray field from centerline to edge and ceiling to floor. The complex spray field is mapped using a sparsely sampled phase-space accounting for all drops produced by the sprinkler. The spray is mapped through fast two-dimensional trajectory calculations spanning this discretized phase-space to produce quantitative views of the spray in regions of interest or in its entirety. Spray patterns are easily extracted from this spray field according to attributes of interest. The ROM is demonstrated by comparing predicted and measured spray patterns generated below a commercial sprinkler. These spray patterns are quantified through spatial distributions of volume flux showing good agreement between measurements and ROM predictions (average error of 0.44 mm/min or 5% of peak volume flux). The speed and robustness of the ROM provide an unprecedented quantitative view of fire sprinkler spraying performance with sufficient accuracy for potential use in engineering design applications.

A simulation on fire dynamic development is needed to see how fire hazard of a building compartment, particularly in a multistory building. The fire development is affected by fire load content, passive (geometry and building openings) and active (detection, alarm and fire sprinkler) system arrangements. This paper discusses fire hazard of a compartment in a multistory building Rusunami in Indonesia. CFD-Fire Dynamic Simulator (FDS) is used for simulation. Fire load content is modelled by using mattress and wardrobe materials. Room layout is based on the built Rusunami. The results show that continuity of fire is affected by air flow through building openings. With less oxygen, at 390 seconds fire develops to produce maximum temperature of 150 o C, at 408 seconds fractional effective dose (FED) of toxic gases reach incapacitate of 0.5 and accumulation such gases significantly increased. At rich oxygen condition, the time needed from ignited stage until critical temperature is around 486 seconds, and after that in 48 seconds flash over occurred suddenly. This data will then be used as available safe egress time (ASET) to check the fulfillment of performance based fire protection approach in a building compartment.

Accurate representation of the fire sprinkler spray enables quantitative engineering analysis of fire suppression performance. Increasingly, fire sprinkler systems are analyzed with computational fluid dynamics (CFD) fire models where the sprinkler spray is simulated with Lagrangian particles dispersed throughout the fire induced flow. However, there is limited guidance for representing the complex, spatio-stochastic characteristics of the initial sprinkler sprays in terms of these Lagrangian particles. The present work establishes a descriptive analytical framework for the initial sprinkler spray that is rigorously grounded in statistical theory, related to local spray properties, and capable of translating high-fidelity measurements into CFD inputs. This framework describes the initial sprinkler spray as a unified probability distribution function, varying over an initialization surface, and statistically representing measurements of near field local spray properties (volume flux, drop size distribution, and drop size–velocity correlation). Lagrangian particles accurately representing the sprinkler spray may be initialized by a stochastic sampling of this probability distribution function. This novel representation enables high-fidelity initialization of the sprinkler spray in CFD fire models, improving their utility in quantitative engineering analysis.

The seismic performance of nonstructural components, including pressurized fire sprinkler systems, plays a significant role during and after an earthquake. A series of full-scale system-level experiments was conducted at the University of Nevada, Reno Network for Earthquake Engineering Simulation site in order to evaluate the seismic performance of integrated ceiling-piping-partition systems. In this study, the performance of fire sprinkler piping systems were evaluated through several design variables. Processing of experimental data led to the calculation of acceleration amplification factors and development of fragility functions. Results show that 50 mm (2.0 in) diameter pipes have the greatest failure probability when evaluating pipe joint rotations.

It is well understood from past earthquakes and experimental studies that non-structural systems suffer more damage and sustain greater losses when compared to structural members. Also, recent years have witnessed significant progress in analytical simulation of non-structural systems. Among these non-structural systems, acoustical lay-in suspended ceilings, fire sprinkler piping and light-gauge steel-frame gypsum partition walls were paid more attention as they contributed to the major construction effort inside a building and damage losses during past earthquakes. This state-of-the-art paper aims to make a comprehensive survey on the recent modelling techniques and sketches a vision for future analytical works that can help the community better assess and improve the seismic performance of acoustical lay-in suspended ceilings, fire sprinkler piping and non-structural light-gauge steel-frame gypsum partition walls.

A full-scale, two-story, two-by-one bay, steel braced-frame was subjected to a number of unidirectional ground motions using three shake tables at the UNR-NEES site. The test-bed frame was designed to study the seismic performance of nonstructural systems including steel-framed gypsum partition walls, suspended ceilings and fire sprinkler systems. The frame can be configured to perform as an elastic or inelastic system to generate large floor accelerations or large inter story drift, respectively. In this study, the dynamic performance of the linear and nonlinear test-beds was comprehensively studied. The seismic performance of nonstructural systems installed in the linear and nonlinear test-beds were assessed during extreme excitations. In addition, the dynamic interactions of the test-bed and installed nonstructural systems are investigated.

The National Fire Protection Association (NFPA) is a US trade association that includes some international members. The association creates and maintains private, copyrighted standards and codes for usage and adoption by local governments. The association publications include model building and codes for equipment utilized by firefighters engaging in hazardous material (hazmat) response, rescue response, and some firefighting. The NFPA was formed in 1896 by a group of insurance firms for the purpose of standardizing fire sprinkler systems. The NFPA's influence grew from sprinklers and fire extinguishers to include standards for building electrical systems in almost all aspects of design and construction. The original membership was limited to insurance underwriting firms; there was no representation from the industries the NFPA sought to control. In 1904, the rules were changed to allow other industries and individuals to participate in the development of the standards to be promulgated. The first fire department to be represented, in 1905, in the NFPA was the New York City Fire Department. Today, the NFPA includes representatives from some fire departments, many fire insurance companies, many manufacturing associations, some trade unions, many trade associations, and engineering associations. Following the Introduction, this chapter reviews NFPA 58 and the History of Odorization. It continues with a discussion of Unknown Dangers to the Consumers of Gas Products. A review follows of Propane: A Colorless, Odorless, and Tasteless Gas. It continues with A Brief Look at the Chemistry of the Life of Mercaptan Odorants followed by Odorant Loss From Absorption/Adsorption. Then a discussion of Combustible Gas Indicators closes the technology presentation. Finally, a Case Study of a Propane Gas Explosion is presented to illustrate what can happen in hazardous situations.

The activation time of a sprinkler has a great impact on the fire growth inside a compartment. The longer time it takes for a sprinkler to activate, the higher the risk of fire to start to spread inside the compartment. In this study, the activation times of off-the-shelf half inch 68°C fire rated pendant sprinklers were assessed through experiments in laboratory settings and eventually best-fit probabilistic curve for the Response Time Index (RTI) were generated from the experimental results. The experiments were conducted in two sets; one set without smoke effect and the other set with smoke effect to determine the activation time and temperature of the sprinkler heads. The data recorded were then used to calculate the RTI and Palisade @ RISK statistical analysis software was used to analyze the best-fit probabilistic curve for the RTIs. It was observed that, average time required for sprinkler to activate was 60 seconds. It was also found that the calculated RTI were within the range of the international sprinkler design guideline. However, the calculated RTI were found to be inconsistent with specified RTI from manufacturer. Based on @ RISK software, the two best-fit RTI probabilistic curve for the two experiments were Gamma and BetaGeneral distribution curve. The probabilistic curves obtained from this work can be used as input for fire in enclosure simulations.

With recent developments in the design and manufacturing process of water-based fire suppression systems , more advanced technologies such as water mist systems have expanded in their building application. In this article, the critical fire suppression mechanisms of water mist systems and conventional fire sprinklers are investigated and compared, with emphasis on the influence of water droplet sizes on the fire suppression mechanisms. Applying computational fluid dynamics (CFD), a fully ventilated fire compartment room has been considered where a methane pool fire was placed at the centre. The considered fire suppression systems were placed directly upon the fire. Thermocouple and gas probes were applied in the computational domain to identify different stages of the fire suppression process, as well as to evaluate the suppression performance. The velocity field was analyzed to examine the penetration effect of suppression systems. Relative humidity and oxygen concentration data obtained by gas analyzers were also studied to further understand the droplet/fire interaction behavior. It was found that latent cooling, volumetric displacement, and dilution of oxygen and fuel were the main suppression mechanisms for water mist systems, as smaller droplets evaporate more efficiently compared to larger ones. On the other hand, for sprinklers, heat extraction by water droplets from the fire was found to be the main suppression mechanism, and the evaporation effect is not as significant as in water mist systems. According to in-depth parametric studies of water droplet sizes, recommendations for the optimal running conditions have been provided for both systems.

BACKGROUND A fire sprinkler head activation occurred during cleaning being performed by environmental services (EVS) in an operating room (OR) suite of a 27 bed OR in a Level I Trauma Center. New fire pumps had recently been installed on the sprinkler system resulting in a reported 30,000 gallons of water discharged into the OR with multiple known areas of encapsulated mold from prior water intrusion. Remediation occurred while minimizing the impact on patient care, maintaining patient safety, isolating half of the OR's under negative airflow and performing air samples for clearance to return to full functionality, and following patients who were undergoing procedures in other ORs for any negative outcomes associated with this water intrusion. METHODS Extraction of water began immediately to areas both horizontal and vertical to the original OR. Removal of equipment and supplies had to occur for the evaluation of any potential contamination. All contaminated, disposable supplies were discarded and all exposed reusable trays were reprocessed by in-house sterile instrument processing department (SPD). The area impacted had to be isolated with poly wall barriers and placed under negative airflow. Specific attention was paid to those areas that had known encapsulated mold, requiring additional barriers and negative airflow. Remediation occurred and air samples were monitored during a six day period. Patients undergoing procedures were monitored for any fungal or bacterial infections. RESULTS Our impacted OR area was segregated off from the remaining OR's restricting the use of approximately half of our OR suites. Cases were able to be rescheduled with none of the patients undergoing procedures at the time of the event have developed any known procedure related adverse events. CONCLUSIONS With quick intervention and actions all water and mold remediation was completed in a timely fashion, with no negative outcomes for patients.

A fire sprinkler system is very important to extinguish fire in the building. The sprinkler system initiates sprinkler discharge if the detection system identifies a developing fire and opens the pre-action valve. However, pre-action fire sprinkler systems mainly installed in the underground parking lot at the apartment complex do not properly operate at fire if the connection type of fire sprinkler systems does not properly installed and operated. This study identified the relationship between fire dispersion & damage and the connection type of water supply in the sprinkler system from many fire cases at the apartment complex in South Korea. In addition, this study also identified the water supply differences and characteristics between South Korea and foreign countries. The main purpose of this study is also to improve the water connection types in the sprinkler system that can reduce the potential failures of pre-action valve operation through electrical signal system. The study also suggests the improvement plan for water connection types in pre-action fire sprinkler system that can minimize potential failure of pre-action fire sprinkler system. The suggestions for revising the fire safe standard in South Korea includes letting the water supply pipe of sprinkler system water inlet connect to the second side of pre-action valve and the water flow device that can minimize potential failure of sprinkler system.

The possibility of microbiologically influenced corrosion was investigated in the early pitted copper pipes. The pipes were installed for less than 6 months as an immergency fire sprinkler. The bacteria were cultured by sampling of corrosion by-product near pits on failed copper pipes for the aerobic as well as anaerobic bacteria. However, only aerobic bacteria was found, which were Micrococcus Luteus and Bacillus sp.. The corrosion rate of copper pipes were studied by weight loss in the groundwater and polarization method. In immersion test as well as the electrochemical polarization test in ground water, only Micrococcus Luteus could activate corrosion of copper by 20% and 15%, respectively. On the other hand, Bacillus sp. showed little effect on corrosion in the above two tests. The shape and characteristics of failed copper pipes as well as simulated copper were investigated using stereoscope, optical microscopy, scanning electron microscope and EDS. The cause of pits were discussed, related with the dissolved copper concentrations, pH, and optical density. It could be concluded that the early failure of copper pipings could be ascribed to the acceration of copper in the presence of bacteria, i.e., Micrococcus Luteus.

For the first time, an analytical modeling methodology is developed for fire sprinkler piping systems and used to generate seismic fragility parameters of these systems. The analytical model accounts for inelastic behavior constituents of the system, including: threaded joints, solid braces, hangers, and restrainers. The model incorporates a newly developed hysteresis model for threaded tee joints that is validated by the experimental results of several tee subassemblies. The modeling technique at the subsystem level is validated by using the experimental results of a sprinkler piping system. The methodology is used to obtain the seismic response of the fire sprinkler piping system of University of California, San Francisco Hospital under a suite of 96 artificially generated triaxial floor acceleration histories. After the component fragility parameters are obtained for the components of the system, three system-level damage states are defined, and a joint probabilistic seismic demand model is utilized to develop system fragility parameters.

The intent is to have a complete system in place, or a “total concept,” providing the safest environment possible for the patients and staff of an ASC. The purpose of the fire alarm system is to identify a fire in its initial development stages and to provide an early notification to the occupants of the facility. Fire sprinkler systems are one of the most important fire protection features incorporated into the total concept of protecting occupants of an ASC from fire. Fire and life safety codes require regular inspection, testing, and maintenance of the emergency power system. The fire and life safety codes require that portable fire extinguishers are checked monthly, which can be done by facility staff, and annual inspection, testing, and maintenance tasks must be performed by a qualified technician.

Fire sprinklers are a type of “active” fire protection system required by fire and life safety codes. The system is activated by heat from a fire, at which time water will be discharged over the fire from the piping system; the water flows from a nozzle, referred to as the fire sprinkler head. It is important to remember that fire sprinklers only discharge water when exposed to heat produced by a fire, and only those sprinkler heads that are exposed to heat will actually discharge water. The codes require all rooms and spaces to be fully protected by fire sprinkler heads, by ensuring that the water spray will cover all the floor area in a room and ultimately the entire building. Fire and life safety codes state that owners and occupants of ASCs are legally responsible for maintaining fire sprinkler systems and keeping the systems in good operating condition.

An efficient safety system at workplace is crucial in order to ensure the workers can save themselves during emergency situation. Emergency exit is the only route for the victims to escape safely. The current problem that occurs is the existing fire sprinkler that installed at the ceiling cannot put out fire for wide area especially at emergency exit. Normally, the fire sprinkler is installed at the middle of corridor ceiling so that, the water cannot cover all the fire. Sometimes victims do not know the location of emergency exit due to the thick smoke so that covered the signboard. Fire fighter also has the difficulty to breach into the building through the emergency exit door because there is still fire. The main objective is to analyze the current safety features system at the workplace and residence then, determined an efficient safety system by designing and developing a safety water sprinkler system at emergency exit. Primary data was collected through an interview with Operating Officer of Fire Department and Rescuer Kangar, Perlis and Consulting Environmental, Mechanical and Electrical Engineers of Perunding HPL Sdn Bhd. For additional information, questionnaire survey was distributed to sixty of people who worked at office or live in flat or apartment. The design of product was simulated to identify the strength and durability of product by running a thermal stress analysis. The value of von misses stress and temperature was increased gradually. The new safety water sprinkler system was used water pump as pumping system. The safety system water sprinkler was installed at the top of emergency exit door and it can cover 2 meter of area. The safety system sprinkled water to clear the fire from block the emergency exit so that the victims can escape from the building within 4 minutes.

[EN] Fire suppression modeling depends on accurate characterization of the atomization processes of fire sprinklers. Numerical modeling, particularly the volume of fluid (VOF) method, has been applied to understanding the atomization behavior of an idealized sprinkler geometry consisting of a 9.5 mm inner-diameter cylindrical nozzle and a flat, 25.4 mm diameter disk with a liquid flow rate of 0.87 L/s. The simulations have been performed with an OpenFOAM based VOF solver, using the isoAdvector scheme for interfacial reconstruction. The sheet breakup distance and film thickness were calculated and compared with measurements from a previous study. A mesh refinement study identified the sensitivities in the predicted quantities to mesh resolution. This study enables further application of the model to simulation of the fully atomized spray., This work was funded by FM Global as part of the Strategic Research Program for Fire and Suppression Modeling. Drs. Hrv Jasak and Vuko Vukčević of Wikki Ltd. are gratefully acknowledged for their guidance in using the isoAdvector and ghost-fluid-method schemes. For part of the simulations, this research used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725

This first of two companion articles presents the results of an experimental program designed to evaluate the seismic behavior of fire extinguishing sprinkler piping systems. Three full-scale pressurized sprinkler piping specimens made of different materials and joint arrangements were tested with various levels of seismic bracing under dynamic loading on the University at Buffalo Nonstructural Component Simulator. All three fully braced specimens performed well under a Maximum Considered Earthquake (MCE) level of loading, validating current code-based requirements for bracing system design. However, unbraced systems, which are typically installed in low to moderate seismic regions or could exist in older construction in active seismic zones, did not perform as well as the fully braced systems. Damage to sprinkler heads, failures of vertical hangers, as well as a complete branch line fracture, were observed during the tests.

The project aim is to design and develop a cloud connected smart LPG gas cylinder platform, acting as a safety device for detecting LPG gas leak at low levels to avoid any possible accidents. It is also capable of sensing fire breakout in the area and weight of the gas in order to provide real time monitoring and alert over Internet. If an abnormal condition is detected, the device sends an alert to the smartphone app of the user and also generates an alert e-mail to other authorities. In addition to this upon detecting a gas leakage or a fire breakout, the device automatically takes safety precautionary measures, like gas valve closing, ventilation opening, fire sprinkler activation and home electrical power supply cut-off. The device connects to the internet via Wi-Fi and thus increasing the mobility of the platform within the premises of the house. A Wi-Fi capable ARM Cortex-M4 microcontroller is used to implement the system. This device offers a complete, low cost, powerful and user friendly way of real-time monitoring and remote control of gas leakages and prevention mechanisms in household and industrial areas.

Seismic damage to fire sprinkler piping systems is not only caused by inertial forces or interstory drifts, but also by impact with surrounding objects. The collision of constituents of piping systems with nearby objects increases the chance of damage to the piping itself and to adjacent objects. In this study, the probability of seismic damage to fire sprinkler systems due to impact is quantified by obtaining seismic fragility parameters for large diameter pipes passing through walls and floors, as well as small diameter pipes that typically interact with suspended ceilings. The results of two shaking table experiments conducted at the University of Nevada, Reno and E-Defense test facility, and a high-fidelity numerical model of a hospital piping system are used to evaluate the displacement demands. Piping interaction fragility curves are generated based on clearances between adjacent objects and pipes. The probability of piping interactions and damage to piping systems subjected to different levels of p...

Modelling the atomization process in fire sprinklers has remained a challenge mainly due to the complexity of sprinkler geometry. A review of existing fire sprinkler spray modelling approaches, including film flow and sheet tracking models, showed that they mainly assumed a constant sheet velocity and linear attenuation of the sheet thickness before its disintegration. In the present study, a liquid sheet trajectory sub-model based on the solution of stream-wise conservation equations has been used to predict both sheet thickness and velocity as it radially expands. This will also help to investigate the extent to which a change in the release angle can affect the sheet characteristics. The analysis carried out shows that the proposed approach improves the predictions of mean droplet diameter and initial droplet speed. A semi-empirical approach is further introduced in the study by using experimental volume fraction measurements to characterize sprinkler sprays in the near field. For a given direction predictions have been conducted for droplet volume median diameter, water volume flux and droplet average velocity at different elevation and azimuthal locations. A reasonably good agreement is found for the near field measurements.

An experimental study is conducted to evaluate the performance of automatic water cannon systems for protecting fire hazards in large-open spaces. As part of this study, typical fire hazards encountered in large-open spaces are simulated to allow for a comparison of water cannon and automatic fire sprinkler protection. Tests are performed to characterize response time, water distribution and effectiveness of protection of the selected water cannon system. Results show that, in general, water cannon can respond to fire events in large-open spaces much faster than sprinklers. Under certain conditions, water cannon can also control and/or suppress the fire. However, further improvement of automatic water cannon technology is needed to optimize system performance for various commodity fires that may occur in large-open spaces.

Standpipe systems are vital to the fire protection of a building. They assist firefighters in getting water to a fire quickly, efficiently, and with sufficient flow and pressure to protect lives, property and the environment. The proper design, installation, inspection, testing and maintenance of standpipe systems is discussed in detail. Chapters cover every aspect of design including piping selection, hanging and bracing, and sizing water supplies. Since fire pumps are also integral to the proper operation of many standpipe systems, there is a significant amount of information on sizing and using fire pumps. Also, since the use of manual standpipe systems in low-rise buildings with fire sprinkler systems is popular, the design of such systems, without fire pumps, is discussed in detail.

So far in this text, the topic of fire sprinkler systems and standpipe systems in the same building has been handled in a generic fashion. The rules for the installation and hydraulic calculation of the standpipe system depend on whether the building is sprinklered or not. But the combination of the two systems using some of the same piping has not yet been discussed. This chapter will delve into the rules of NFPA 13 and NFPA 14 regarding the combination of the sprinkler system and standpipe system for at least some of the piping in the building. See section 7.10.1.1.5 in NFPA 14 for more information on this requirement.

Measurements were conducted to characterize the spray patterns of an upright fire sprinkler in the near and far field of the sprinkler. The spatial distribution of droplet size, velocity and number density in the spray was measured using a laser-based shadow-imaging system. The water volume flux distribution was measured by an array of pressure-transducer-equipped water collection tubes and containers. A large-scale traverse was constructed to move the laser optics and water collection tubes and containers to the designated measurement locations. An upright fire sprinkler with a K-factor of 162 lpm/bar1/2, installed with its deflector 0.17 m below a flat horizontal ceiling, was characterized at two discharge pressures, i.e., 0.76 bar and 1.31 bar. In the near field at 0.76 m from the sprinkler, measurements were performed in a spherical coordinate at different azimuthal and elevation angles with respect to the sprinkler deflector. In the far field, the sprays were mapped out in a 110° circular sector at 3.05 m and 4.57 m below the ceiling. The shadow-imaging based water flux measurements were verified by the measurements obtained from water collection containers. Except for the pipe effect, the azimuthal distributions of the flow rate showed that the spray pattern was more influenced by the frame arms than by the deflector tines and slots. The gross droplet size distribution was expressed as a combination of a log-normal function and Rosin–Rammler function. The median droplet diameter was correlated as an empirical function of the sprinkler orifice diameter and operating pressure. The near-field distributions of the droplet size, velocity and flux can be used to prescribe the starting spray conditions for numerical simulations of spray transport. The far-field measurements are useful in evaluating the spray transport calculations.

The spray patterns of a pendent fire sprinkler were characterized through experimental measurements in the near and far field of the sprinkler. A laser-based shadow-imaging system was used to measure the droplet size, velocity and number density in the spray. An array of pressure-transducer-equipped water collection tubes and containers provided a separate set of water volume flux measurements. A large-scale traverse was constructed to move the laser optics and water collection tubes and containers to the designated measurement locations. A pendent fire sprinkler with K-factor of 205 lpm/bar1/2 (14.2 gpm/psi1/2) was characterized at two discharge pressures 3.5 bar and 5.2 bar (50 and 75 psi). In the near field at 0.76 m from the sprinkler, measurements were performed in a spherical coordinate at different azimuthal and elevation angles with respect to the sprinkler deflector. In the far field, the sprays were mapped out in a 110° circular sector at 3.05 m and 4.57 m below the ceiling. The shadow-imaging based water flux measurements were verified by the measurements obtained from water collection containers. The measurements show that the spatial distributions of water volume flux, droplet size and velocity of sprinkler sprays are strongly influenced by the sprinkler frame arms and the configuration of sprinkler deflector’s tines and slots. For the purpose of fire protection analysis, empirical correlations were developed from the near-field measurements to prescribe the spray starting conditions for the numerical modeling of spray transport through fire plumes. The far-field measurements can be used to evaluate the spray transport calculations.

The current state of fire sprinkler effectiveness information has been found to be a limiting factor when comparing the fire risk for alternative building designs in New Zealand (Determination 2005/109: single means of escape from a high-rise apartment building. Department of Building and Housing, Wellington, 7). Data on the past performance of systems in real fires is one of the best sources of information to estimate future performance, but there has not been a detailed study on sprinkler effectiveness data from fire incidents in New Zealand published since Marryatt’s work (Fire: a century of automatic sprinkler protection-revised. Australian Fire Protection Association, Melbourne, 13), which was last updated in 1986 and included data from Australia. The current research looks at the quality and quantity of data available on sprinkler effectiveness from New Zealand Fire Service (NZFS) incident reports over the period of 2001 to 2010 to evaluate the data’s usefulness for risk-informed building fire safety design. A comparison is made between the number of sprinklers reported activated in the NZFS dataset, Marryatt’s study, guidance from PD 7974-7:2003 (PD 7974-7:2003: the application of fire safety engineering principles to fire safety design of buildings. Probabilistic Risk Assessment, London, 3), and NFPA data (U.S. experience with sprinklers and other automatic fire extinguishing equipment. National Fire Protection Association, Quincy, 12). Proposals to improve the collection and reporting process to increase the informative value of future NZFS data for risk-informed fire safety design are presented.

A preliminary study at low water discharge pressures was conducted to investigate the fire sprinkler spray formation as affected by sprinkler geometry using a laser-based shadow imaging system. A sprinkler typically consists of the following components: a deflector with tines and slots, a boss above the deflector and sprinkler frame arms. Prototypes of these components were fabricated to evaluate their effects on the spray formation process. The water sheet thickness formed on non-slotted deflectors, slot spray discharge angle, sheet breakup distance from the deflector perimeter, water flux and drop size distributions were measured. It was found that deflector diameter and boss structure have little impact on drop size and sheet breakup distance. However, wider slots form larger drops. At constant operating pressure, the slot spray discharge angle is insensitive to the slot width, but sensitive to the boss that helps directing the slot spray toward the sprinkler centerline. The frame arm tends to produce a vertical spray sheet downstream of the frame arm, which increases the complexity of overall spray formation. An integral model was developed to calculate the development of water sheet thickness and speed on the deflector for different degrees of viscous effect exerted by the deflector. An empirical correlation was also established to estimate the spray flux fraction discharging from a deflector slot. The above measurements and observations are useful for the development of a spray formation model for fire sprinklers.

In the early days, hazards of fire were limited to its thermal hazards. With the advancement of civilization, science and industry, the lifestyles of people have changed, including their housing trends, i.e. space, insulation and ventilation, the hazards of other components of the fire has surfaced. Three family members and a niece were found dead inside their airtight, locked house, in a morning by the driver. The pantry area which opened into the living room had evidence of fire. At the autopsy, all four bodies were covered with black soot, but there were no burns in bodies or clothing. The cause of deaths was given as death due to smoke inhalation. The circumstance of the deaths was ascertained as accidental. Even though deaths due to smoke inhalation are rare, with air-conditioning and insulation of houses, the hazards of smoke have increased in Sri Lanka. Therefore, installations of smoke alarms or fire sprinkler systems are recommended to prevent such deaths in the future.

A recent study on the environmental impact of automatic fire sprinklers is documented in a two part series. The present paper examines the relationship of automatic fire sprinkler technology to environmental sustainability. Large-scale fire tests were conducted using identically constructed and furnished living rooms. In one test, fire extinguishment was achieved solely by fire service intervention, and in the other, a single residential automatic fire sprinkler was used to control the fire until final extinguishment was achieved by the fire service. Comparisons of the total greenhouse gas production, quantity of water required to extinguish the fire, quality of water runoff, potential impact of wastewater runoff on groundwater and surface water, and mass of materials requiring disposal between the two tests were made. The results show that in addition to providing life safety and limiting property damage, the use of automatic fire sprinklers is a key factor in achieving sustainability.

Sprinkler heads are a mature product that can fail to function via a variety of different mechanisms. Mechanical damage and corrosion can occur year round. Additionally, there can be seasonal failures due to creep of fusible alloys in summer. Serious problems also have occurred due to sticking of sliding O-ring seals. These problems have lead to product recalls, and subsequent revisions in design standards.

Performance based methodologies are becoming increasingly common in fire safety due to the inability of prescriptive codes to account for every architectural feature. Fire Sprinkler suppression systems have long been used to provide property protection and enhance life safety. However, very few methodologies exist to account for the impact of sprinkler sprays on fire scenarios. Current methods are extremely complicated and difficult to use as an engineering tool for performance based design. Twenty-four full scale fire tests were conducted at Tyco Fire Suppression & Building Products Global Technology Center to determine a simple method for accounting for the impact of a single residential sprinkler on fire induced doorway flows. It was found that a spraying sprinkler reduced the mass flows at the doorway while maintaining two stratified layers away from the sprinkler spray. The mass flow reduction was consistent and could be predicted through the use of a simple buoyancy based equation. The current study suggests that the buoyancy equation can be altered through the use of a constant cooling coefficient (equal to 0.84 for a Tyco LFII (TY2234) sprinkler) based on the test results reported in this paper. This study is a proof of concept and the results suggest the methodology can be applicable to similar situations.

A benefit–cost analysis is performed to measure the expected present value net benefits (PVNB) resulting from the installation of a residential fire sprinkler system in a newly constructed, single-family house. The benefits and costs associated with installation and use of a fire sprinkler system are compared across three prototypical single-family house types: colonial, townhouse, and ranch. Each of the house types varies by design, size, and fire sprinkler affordability. Six fire sprinkler system designs are evaluated: a multipurpose network system, three stand-alone systems, and two stand-alone systems equipped with a backflow preventer. The sprinkler designs vary by installation cost (materials and labor cost) and required annual maintenance, but all were designed to meet the NFPA 13D standard. The estimated benefits of fire sprinklers include reductions in the following: the risk of civilian fatalities and injuries, homeowner insurance premiums, uninsured direct property losses, and uninsured indirect costs. Results show that residential sprinkler systems not requiring expensive annual upkeep or maintenance are economical. The expected PVNB in 2005 dollars is estimated as $2,967 for the colonial-style house, $3,099 for the townhouse, and $4,166 for the ranch-style house, given installation of the lowest life-cycle cost sprinkler system in each of the house types. A sensitivity analysis that measures the variability of the results to changes in the modeling assumptions confirms the robustness of the baseline analysis.

Safety is one of the major concerns of process safety engineers in most industrial facilities all over the world. To this scope, some events play an important role once the effect of their consequences can be assumed as totally undesirable. One of these events refers to the occurrence of a fire. Such event can result in catastrophic consequences for life, equipment, and continuity of activities or even leading to environmental damage. A fire protection equipment with low reliability means that this equipment are often unavailable and thus the risk of a fire increases. Maintenance of fire protection equipment is very important because this kind of systems is mostly in a dormant mode, which gives uncertainty about their operability when demanded in a real situation of fire. This article outlines the importance of tests, inspection, and maintenance operations in the context of a fire sprinkler system and proposes a methodology based on international standards and supported by test/inspection reports to correct the frequency of these actions according to the level of degradation of the components and regarding safety purposes. © 2015 American Institute of Chemical Engineers Process Saf Prog 35: 84–91, 2016

A comprehensive analytical model is developed for a pressurized fire sprinkler piping system of a hospital building. A suite of ninety-six artificial triaxial floor acceleration histories is used to generate seismic fragility parameters of the sprinkler piping system. The analytical model accounts for the inelastic behavior of braces, hangers, and wire restrainers. It incorporates an experimentally validated hysteresis model developed, as part of this study, for the moment-rotation relationship of grooved fitted joints. Component fragility parameters were obtained for lateral restrainers, hangers, and pipe joints. Three system-level damage states were defined based on the level of functionality of fire sprinkler systems and severity of leakage after a seismic event and a joint probabilistic model were utilized to obtain system-level fragility parameters. Finally, the seismic fragility of fire sprinkler systems with grooved fit joints is compared to that of a piping system with threaded joints.

The reaction of a fire plume to an applied water spray is crucial to fire suppression. While considerable research has been devoted toward fire plumes without suppression, and some computer simulations of fire suppression have provided insight, little experimental data exist detailing how the structure of a fire plume changes during suppression. Experiments were performed in which 5, 15 and 50 kW gas burner fires were exposed to a spray from one of three spray sources. Flow rates from the nozzles or fire sprinkler ranged from 6 to 106 L/min. Contours of infrared (IR) intensity of the fire plume show that the plume decreases in height and increases in width with the increasing strength of the applied spray. Based on the height of the maximum fluctuations of IR intensity, the thermal plume height decreases with increasing spray strength, but the overall projected area of the plume changes very little. The plume height depends on the ratio of the drag of the droplets on the air to the momentum of the plume, allowing the results to be generalized to typical fire suppression applications.

Equations describing the fluid motion in buoyant plumes have been applied to fire plumes by researchers and engineers since Morton et al. developed them in the 1950s. However, in the application of active fire suppression by water droplets, the equations are no longer valid. The equations have been modified to include the effect of a homogeneous, uniform velocity droplet field on the momentum of the fluid. Solving the resulting ordinary differential equations shows that the plume widens and the upward velocity of the plume slows significantly due to the presence of droplets. Results from this simple model appear to match the results of more sophisticated numerical simulations. The model further demonstrates that the interaction between the upward momentum of the plume and the downward momentum of the droplet spray can be critical for fire suppression.

This article is a guide for sprinkler contractors, facilities managers, and their technical advisors who sometimes have to deal with the consequences of iron-water corrosion inside pressurized, low-carbon steel fire protection systems that contain water. The consequences include: (1) pinhole leaks and (2) build-up of insoluble corrosion residues on the interior pipe wall that increases pipe friction losses. A reference is made to sections of the National Fire Codes/NFPA 13 that address pipe materials, protection of steel piping against corrosion, and pipe friction losses. Electrochemical metal-water corrosion processes that can occur inside pressurized, low-carbon steel fire protection systems that contain water are discussed, as is microbiologically influenced corrosion. Corrosion control measures arising from the electrochemical science underlying both metal-water corrosion and microbiologically influenced corrosion are suggested.