Fire Sprinkler Systems Research Articles

Design and Development of Corrosion Resistance Coating for Pipes in Fire Protection Sprinkler Systems : A Review

Fire pumping systems are often used in most buildings for firefighting, whether they are residential, commercial, industrial or of any other kind. Such systems are responsible for the water flow and pressure necessary for manual or automatic devices designed to build safety. Therefore, ensuring their availability when an unexpected fire event occurs is very critical. But due to the presence of dissolved oxygen in the water-filled in the pipes, corrosion takes place at some point in time. This will lead to several types of failures in the system if the system is not properly designed with the right material for the environmental conditions and water quality, which in turn will render the system ineffective. This paper discusses the reasons for corrosion in the piping of fire sprinkler systems and their mitigation.

Critical assessment on operating water droplet sizes for fire sprinkler and water mist systems

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.

Investigation on Frequency Reconfigurability of a Microstrip Patch Antenna Using a Ni-Ti Shape Memory Alloy for an Automatic Fire Sprinkler System

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.

Tragic death of a family due to house fire

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.

Predicting sprinkler spray dispersion in FireFOAM

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).

Influence of an Extended Domestic Drinking Water System on the Drinking Water Quality

Drinking water and fire safety are strongly bonded to each other. Actual drinking water demand and fire flows are both delivered through the same network, and are both devoted to public health and safety. In The Netherlands, the discussion about fire flows supplied by the drinking water networks has drawn fire fighters and drinking water companies together, searching for novel approaches to improve public safety. One of these approaches is the application of residential fire sprinkler systems fed by drinking water. This approach has an impact on the layout of domestic drinking water systems (DDWSs), as extra plumbing is required. This study examined the influence of the added plumbing on quality of both fresh and 10 h stagnant water in two full scale DDWSs: a conventional and an extended system. Overnight stagnation was found to promote copper and zinc leaching from pipes in both DDWSs. Microbial numbers and viability in the stagnant water, measured by heterotrophic plate count (HPC), flow cytometry (FCM) and adenosine tri-phosphate (ATP), depended on the temperature of fresh water, as increased microbial numbers and viability was measured in both DDWSs when the temperature of fresh water was below the observed tipping point (15 °C for the HPC and 17 °C for the FCM and ATP measurements respectively) and vice versa. A high level of similarity between water and biofilm communities, >98% and >70–94% respectively, indicates that the extension of the DDWS did not affect either the microbial quality of fresh drinking water or the biofilm composition.

A-40 スプリンクラー設備銅配管システムの開発(II) : はんだ付継手部の耐熱性に関する評価

A-40 スプリンクラー設備銅配管システムの開発(II) : はんだ付継手部の耐熱性に関する評価

A-39 スプリンクラー設備銅管配管システムの開発(I) : 管材・工法・経済性に関する評価

A-39 スプリンクラー設備銅管配管システムの開発(I) : 管材・工法・経済性に関する評価

Study on Fire Dynamic Development in a Multistory Building Compartment

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 390seconds fire develops to produce maximum temperature of 150 oC, at 408seconds 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 486seconds, and after that in 48seconds 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.

Spray dispersion measurements of a sprinkler array

A careful measurement methodology has been developed for highly resolved spray dispersion measurements. These measurements are used to establish spatial resolution requirements for evaluation of sprinkler spray patterns and to provide a comprehensive data set for computer model validation. For this study, four nozzles were arranged in a square configuration typical of fire sprinkler system installations. Volume flux of water delivered to the floor was measured 1.5m below the array at locations on a 50mm grid. The detailed measurements accurately portray the spatial variations existing in the spray and indicate that each sprinkler contributes a unique spray pattern. The total mean volume flux was 5.9mm/min, with local measurements ranging from 25% to nearly 400% of the mean value. A spatial averaging analysis suggests that at least 25 measurements should be taken across the reach (i.e. extent) of the spray to resolve gradients in the spray pattern. Fewer measurements provide limited insight beyond the overall mean flux (due to resolution errors), while more measurements become increasingly expensive and less accurate (due to repeatability errors). To quantify the significant spray pattern variations, a meticulous measurement and alignment routine is described to ensure results are sufficiently comprehensive, detailed, and accurate for use in computational model validation.

A description of the initial fire sprinkler spray

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.

Experimental Fragility Analysis of Pressurized Fire Sprinkler Piping Systems

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.

Analysis of pitting corrosion failure of copper tubes in an apartment fire sprinkler system

Abstract Microscopical and structural analyses as well as visual inspection of copper tubes were used to investigate the cause of pitting corrosion failure of copper tubes in the wet pipe sprinkler system. Chemical analysis of the water in the copper tubing and XRF/XRD analysis of its sediments were also used to obtain hints on what was happening in the copper tubing during the progress of the pitting corrosion. It was found from the failed copper tube that a significant amount of pressurized air was present over the water in the copper tubing during operation and a series of corrosion pits were aligned adjacent to the water/air line. The waterline localized corrosion, a type of differential oxygen concentration cell corrosion, induced by pressurized air over the water in the copper tubing was identified as the cause of the pitting corrosion failure. A state of a very low oxygen concentration was maintained under the envelope of a dense layer of malachite, the corrosion byproduct, which was evidenced by the formation of Cu2O crystalline particles inside the corrosion pit. CuO particles observed on the inside surface of the copper tube do not seem to help prevent local as well as general corrosion. Accelerated pitting corrosion of the copper tube in the wet fire sprinkler system was simulated using a differential aeration cell. Finally, measures for stopping or delaying the pitting corrosion of the copper tube in the wet sprinkler system are suggested.

Response of a 2-story test-bed structure for the seismic evaluation of nonstructural systems

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.

효과적인 소방활동을 위한 지하주차장 스프링클러설비 송수배관 연결방식의 개선에 관한 연구

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.

Maintenance of fire sprinkler systems based on the dynamic assessment of its condition

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

Deformation Analysis of Assembly Load on Fire Extinguishing Sprinkler Head

The necessity about the installation of fire extinguishing sprinkler system came to the fore as fire accidents are increased for small-scale building. For this reason, it is making an effort to simplify the sprinkler system, and it becomes necessary to redesign a conventional sprinkler head. However, the numerical analysis of a sprinkler head has not been found in the literature. Meanwhile, a fusible alloy which is used as an operation switch of sprinkler head is weak in strength, and a force which needs to assemble the sprinkler head is also added to the internal parts including the fusible alloy. Futhermore, it is also difficult to analyze only through experimental method, because the sprinkler head which is structurally complex is composed of various parts. So far, it takes a long time to develop a reliable sprinkler head due to trial and error in experiment. Accordingly, in order to redesign or optimize the sprinkler head efficiently, it needs to observe the internal changes while assembling parts. Therefore, the aim of this study is to build the analytical model of a reliable conventional sprinkler head. Meanwhile, inner and outer loading plates are deformed by the force in the assembly process, and their deformations are used as a standard for building a model of sprinkler head. In this respect, the design method based on the deformation analysis by using FEM is used in this paper. Additionally, it needs to investigate the stress of FM for improving the stability of sprinkler head. Thus, the deformation and stress distributions are described visually and numerically by the simulation results which are not able to be evaluated by experiment.

Seismic Fragility Study of Fire Sprinkler Piping Systems with Grooved Fit Joints

AbstractA 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.

Seismic Fragility Study of Displacement Demand on Fire Sprinkler Piping Systems

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 peak floor acceleration is compared for different clearances. It is found that the probability of damage due to impact is comparable with the probability of exceeding other limit states, like the leakage in fittings, when a 1 in or 2 in gap is provided around large and small diameter pipes, respectively.

Fire Performance Assessment of a Fiber Reinforced Polymer Wall Panel Used in a Single Family Dwelling

This paper describes a fire performance assessment of a sandwich panel selected as the primary material in a high-performance house developed for the 2013 China Solar Decathlon competition. The sandwich panel has fiber reinforced polymer skins and a foam plastic core. Evaluation of fire performance showed that the selected panel would not comply with U.S. building code requirements for a single-family dwelling without additional protection. However, the use of an intumescent fire protective coating, coupled with the installation of a residential fire sprinkler system, is shown to be effective in meeting the intent of the fire and life safety requirements of the International Residential Code. Fire testing shows that the application of an intumescent fire protective coating to the panels significantly decreases the heat release rate, the smoke production characteristics, and the extent of flame spread on the panels.