• Fire Science and Engineering
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• v.21 no.4
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• pp.1-11
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• 2007

This study aims to investigate, review, and summarize the definition, development, and applications of "percent agent in pipe", "percent of agent in pipe" which is used as a key factor in testing and evaluating the performance of gaseous fire extinguishing agents, including Halon 1301 and $CO_2$. This study also analyzes and compares the local and international standards on testing and evaluating the performance of gaseous fire extinguishing systems, as well as the results of system performance tests conducted as a part of performance evaluation and approval programs for gaseous fire extinguishing systems, especially, Korean Gaseous Fire Extinguishing System Performance Approval Program called KFI Approval. Percent agent in pipe was defined first in NFPA 12A, Standard on Halon 1301 Fire Extinguishing Systems, dating back to the 1970's. After the phaseout of Halon 1301 systems in 1994 in the developed countries, the percent agent in pipe has been widely used in Halon 1301 alternative clean agent fire extinguishing systems, both halocarbon clean agent systems and inert gas clean agent systems, as an essential criterion to assure the system design accuracy, determine the limitations and performance of a system, and to predict the system performance results accurately, especially, in association with their system flow calculations. Underwriters Laboratories has their own standards such as UL 2127 and 2166 applying percent agent in pipe in testing and evaluating the performance of clean agent fire extinguishing systems. As a part of a system performance test and approval program called KFI Approval System, Korea also has started to apply the percent agent in pipe as a key factor to test, evaluate, and approve the performance of gaseous fire extinguishing systems, including both high and low pressure $CO_2$ systems, from the early 2000's. This study outlines and summarizes the relevant UL and KFI standards and also describes the actual test resultant data, including the maximum percents of agent in pipe for gaseous fire extinguishing systems. As evidenced in lots of tests conducted as a part of the system performance test and approval programs like KFI Approval System, it has been proven that the percent agent in pipe may work as a key factor in testing, evaluating, and determining the limitations and performance of gaseous fire extinguishing systems, especially compared with the hydraulic flow calculations of computer design programs of gaseous fire extinguishing systems, and will remain as such in the future. As one thing to note, however, there are some difficulties in using the unified percent agent in pipe to determine the maximum lengths of pipe networks for gaseous fire extinguishing systems, because the varying definitions used by some of the flow calculations (not in accordance with NFPA 12A definition) make it impossible to do any direct comparison of pipe lengths based on percent agent in pipe.

• Journal of the Korean Society of Safety
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• v.23 no.6
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• pp.95-99
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• 2008

Halon was known as a cause of the ozone layer destruction. In 1987, it was designated as one of the ozone-layer-destroying materials in the Montreal Protocol. Therefore substitutes of Halon agent has been developed including inert gas extinguish system, which is one of the most widely used fire extinguishing system. This study intended to increase the efficiency of inert gas extinguishing agent by using inert gas additives. As IG-541 shows high extinguishing power, the experiment was performed to measure the effects of gaseous additives to it. Cup-burner fire extinguishing apparatus was used with n-Heptane fuel. Among many of pure inert gaseous agents, Helium showed the most excellent extinguishing power. When Helium was added to IG-541, fire extinguishing power was increased and the concentration of oxygen in chimney also risen. By adding Helium to IG-541, the effectiveness of inert gas fire extinguishing system is able to be increased.

• Fire Science and Engineering
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• v.33 no.4
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• pp.77-82
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• 2019

Fire extinguishing systems are essential equipment in all indoor facilities to address unexpected fire scenarios, and appropriate fire extinguishing agent should be used depending on the place and object to protect. Among these, gaseous fire-extinguishing systems are used to protect electronic equipment. Therefore, inert gases that do not undergo chemical reactions are used mainly in those systems. On the other hand, recently, owing to the high integration of electronic equipment, there are some cases, in which large noise generated from gaseous systems damage the electronic equipment. In this study, numerical analysis of the discharge noise with various nozzle contraction angles was carried out to improve the gas fire extinguishing system. Numerical analysis was carried out using ANSYS FLUENT ver 18.1. The causes of the noise were elucidated using the swirl distribution. The noise level of the modified model was reduced by approximately 6 dB compared to the reference model, which is similar to the result of a previous study, confirming the validity of the method.

• Fire Science and Engineering
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• v.29 no.1
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• pp.60-66
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• 2015

The present study was aimed to analyze enclosure integrity test, which is the performance experiment of soaking time, in a fire zone equipped with gaseous extinguishing system in an effort to find understand the effect of precaution factors upon the success of fire extinguishment. To achieve the goal of this study, it divided the fire zones of internal and external power plants into ones taking precaution measures and not taking them and then enclosure integrity test was given respectively. Therefore, this study examined the success rate if the test according to the presence and absence of the precaution measure and confirmed the failure factors, designed concentration soaking time and proportion of leakage area to total volume area by type of gaseous extinguishing system and rooms. Precaution measures were applied to the fire zones without them to confirm the increase of the success rate of enclosure integrity test. By doing so, it was found that reduced number of experiments caused by failure led to cost saving.

• Journal of Korean Institute of Fire Science & Engineering
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• v.1 no.1
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• pp.10-18
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• 2000

• Fire Science and Engineering
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• v.26 no.6
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• pp.1-6
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• 2012

There are specific indications about additional gas for the unencloseable openings of the carbon dioxide extinguishing systems. But there are no indications for other gas extinguishing systems including clean agent extinguishing systems only have the principle when it need, apply it. Therefore, this study suggested applying the equation of additional gas for the unencloseable openings of the carbon dioxide to all of the other fire suppression gas that we are use.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2003.10a
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• pp.126-131
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• 2003

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.550-557
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• 1997

Production of so-called Halon fire extinguishing agents has been prohibited since January 1994 because of their ozone depletion potential, To replace them, several hydrofluorocarbons and fluorocarbons have been developed and utilized. A number of studies on flame extinguishing concentrations and flammability peak concentrations of them have been done. Although there was enough information for practical purpose, more knowledge on fire extinguishing characteristics of them should be attained for efficient use of them. In this study, peak concentrations of methane/air mixtures with gaseous halogenated hydrocarbons were measured at elevated temperature, because the former studies were done at room temperature and temperature of a fire room can be higher than usual. Measurement was done at $200^{\circ}C$, because measuring system could not endure higher temperature. This study revealed that peak concentrations of halogenated hydrocarbons differed little at elevated temperature. The halogenated hydrocarbons have almost the same fire extinguishing ability as Halon 1301.

• Journal of Korean Institute of Fire Science & Engineering
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• v.1 no.1
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• pp.2-9
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• 2000

• Fire Science and Engineering
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• v.30 no.2
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• pp.43-48
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• 2016

One of the main problems with gaseous fire extinguishers is the decrease in fire suppression capability due to the leakage of the fire extinguishing agents, either naturally or caused by obsolete equipment. Therefore, in this study, a real-time detector module for monitoring pressure leakages was developed and an assessment on its performance was carried out. Currently, there are no domestic or global standards for testing pressure leakage detection systems. Therefore, similar global standards, such as ISO 7240 and FM 1421, and the domestic law on "Receiver type-approval and technical standards for product inspection" were used as a reference for assessing the performance of the newly developed module. Its basic performance was assessed by applying compressed air to the module, and, as a result, the minimum working pressure was identified as 0.3 bar. Its environmental qualification was carried out to confirm the proper functioning of the module in different climates and the module was confirmed to function properly at both high ($50^{\circ}C$) and low ($-10^{\circ}C$) temperatures.