• Fire Science and Engineering
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• v.24 no.5
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• pp.94-101
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• 2010

The pipes using in water-based fire protection systems are used steel pipes for ordinary piping, carbon steel pipes for pressure service, copper and copper alloy seamless pipes and tubes, etc. By last buildings of high-rising, complexity, in fire protection systems, the corrosion resistance, easy construction, lightweight and cost-effective use of the pipes is being considered. Among the pipes, the possibility of used for fire protection system being used in the existing copper pipe of material properties, strength, corrosion resistance, heat resistance through and compare the performance was evaluated. As a result of that assessment light gauge stainless steel pipes for ordinary piping (KS D 3595) at a water pressure of less than 1.2 MPa can be used in sufficient physical properties, strength, corrosion resistance, heat resistance and have been observed.

• Fire Science and Engineering
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• v.26 no.4
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• pp.70-76
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• 2012

This paper deal with vehicle fire caused by damage of diesel particulate filter (DPF) on diesel passenger vehicles. In order to reduce particulate matters included exhaust gases, a DPF in the exhaust system were installed diesel vehicles. A DPF was broken by excessively trapped particulate matters, regeneration error with a malfunction of ECU and defect of suction system such as swirl valve. If the DPF was broken, hot exhaust gases was released to the bottom of vehicle and released hot exhaust gases lead to occur the fire through combustible materials around the exhaust system. When a fire happened in the diesel vehicle caused by damage of DPF, silicate inorganic compounds were attached to the exhaust ventilation pipe and muffler. The silicate inorganic compounds were created by DPF combustion consisting of raw material ceramics. If the silicate inorganic compounds attached to the tail pipe in the diesel passenger vehicles, its fire cause will be assumed damage of DPF.

• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.120-125
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• 2005

Formwork is a temporary structure that supports its weight and that of freshly placed concrete as well as construction live loads. Among the accidents and failures that occur during concrete construction, many are formwork failures which usually happen at the time concrete is being placed. In constructions site, pipe supports are usually used as shores which are consisted of the slab formwork. The strength of a pipe support is decreasing as it is frequently being used at the construction site. The objective of this study is to find out the strength change of used pipe support and unused pipe supports according to aging. In this study, 2857 pipe supports were prepared. Among these pipe supports, 2337 pipe supports were lent to the construction companies fire of charge. 520 pipe supports were kept on the outside. Compressive strength was measured by knife edge test and plate test at each 3 month. Test results show that the strength of unused pipe supports as well as used pipe supports was decreasing according to age, use frequency and load carrier, and the strength of used pipe supports was lower than the strength of unused pipe supports at the same age. So, the strength of used pipe supports from 191 days to present day was not satisfied the specification of KS F 8001. According to these results, it shows that attention has to be paid to formwork design using used pipe supports. Therefore, the present study results will be able to provide a firm base to prevent formwork collapses.

• Fire Science and Engineering
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• v.32 no.2
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• pp.38-47
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• 2018

In this study, we compare the engineering seismic design method considering the physical properties of piping materials and the specification-oriented design method according to the seismic design standards of fire fighting equipment. In the case of the seismic design method considering the physical properties of piping materials, the safety of the piping will be analyzed through the combined value of the torsional stress and the bending stress generated in the piping. However, in the case of the design-centered design method, instead of the safety of the piping material, it calculates the moving force of the pipe and interprets whether or not the shaking prevention strut can bear. Fire extinguishing equipment piping is possible through safety analysis of stress and displacement of piping material because piping safety can not be secured via unstable force generated in a certain section with one connected structure is there. Therefore, it is necessary to apply analytical method considering seismic performance of building structure and material properties of piping for seismic design of safe fire extinguishing system piping.

• Fire Science and Engineering
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• v.17 no.4
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• pp.86-91
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• 2003

Since the air stream in the room controlled by HVAC system affects on he expected response of conventional detectors which are designed in accordance with normal characteristics of air stream in the fire incident, unexpected operation time delay may occur in fire. In order to solve this problem and to improve sensitivity so that to initiate fire in its early stages for minimizing damage and protecting people, we studied and developed Air Sampling Smoke Detector. The Air Sampling Smoke Detector is a kind of active-type fire detection system. it draws air continuously from the protected area through an air sampling pipe network to the smoke density analyzer. This study presents smoke density analysing technique and air intake balancing technique through an air sampling pipe network. As a result of evaluating, Air Sampling Smoke Detector was much more sensitive than conventional smoke detectors that passively wait for smoke to reach them and was not affected by ambient airflow in the room by means of balanced air intake through the sampling holes.

• Journal of the Korean Institute of Gas
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• v.4 no.3 s.11
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• pp.33-38
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• 2000

When fire and explosion accidents have occurred due to a leak of the flammable gas involving the LNG & LPG in an industrialized society, it is a very important problem. Accordingly, in this paper, we have compared and analyzed the occurrence transition and the electrostatic energy according to dust supplies and pressure variations for the electric charge due to the gas-solids of pipe flow. As the experimental results, if dust amounts and the initial pressure increased, electric charge in the pipe and the exit increased. The Specific charge of $Fe_2O_3$ increased proportionally if the initial pressure increased but if the quantity of dust increased, the specific charge decreased. Energy increased significantly as the dust amounts and the initial pressure increased. The possibility of fire and explosion exist in the measuring point(M 1) and the Faraday cage if natural gas and LPG were used.

• Journal of Korean Association for Spatial Structures
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• v.23 no.2
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• pp.53-60
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• 2023

Recently, a novel cast-in specialty insert was developed in Korea as an anchor for lightweight pipe supports, including fire-protection pipes. As these pipe supports and anchors play a critical role in transferring loads of fire-protection pipes to structural members, it is crucial to evaluate their seismic performance before applying the newly developed insert. In this study, the seismic shear performance of the insert anchors was evaluated through cyclic loading tests based on the loading protocols of ACI 355.2 and FEMA 461. Initially, five monotonic loading tests were conducted on the insert anchors in cracked concrete, followed by cyclic loading tests based on the monotonic test results. The findings revealed that the insert anchors exhibited negligible decrease in shear strength even after cyclic loading. Furthermore, a comparison of the maximum load and displacement of the insert anchors obtained under the loading protocols of ACI 355.2 and FEMA 461 was performed to investigate the applicability of the FEMA 461 loading protocol for anchor performance evaluation.

• Journal of the Korea Safety Management & Science
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• v.26 no.1
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• pp.9-14
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• 2024

Restraints of Branch Lines are used as earthquake-resistant support devices for fire-fighting pipes along with sway brace devices. The central types are aligned and fixed in a straight line with center of the pipe, but the eccentric types are fixed to on side of the pipe, so a bending moment occurs. In this study, three specimens each of central type and eccentric type were installed at an angle of 45° from the vertical and a monotonic compression load of 1340N was applied. All central type samples satisfied 17.8mm of the allowable displacement, but all eccentric type samples failed to meet the target load and buckled. Therefore, when considering the performance of eccentric type restraints, both compressive load and bending moment must be considered. Even through material mechanics calculations, the yield stress of eccentric type - 3/8 inch all threaded steel bolt - exceeds 320Mpa of the allowable stress. A experiment standards need to be established for eccentric type restraints.

• Geomechanics and Engineering
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• v.30 no.6
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• pp.517-524
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• 2022

Every year, millions of waste tires are discarded across the world. Storage of waste tires presents many problems such as fire threats, epidemics, and non-economic factors. Furthermore, the disintegration process of waste tires is not economical or practical due to its time-consuming, and disposal requirements. In this study, half-section waste tires (HSWTs) were integrated with high-density polyethylene (HDPE) pipes under different relative density conditions. The main aim of the study was to reduce the deformation values of embedded HDPE pipes in sandy soil and to evaluate the soil-pipe interaction. In comprehensive laboratory tests, half-section waste tires were integrated in two different ways: in the middle of the pipeline and along the pipeline. Accordingly, it was concluded that the effectiveness of waste tires reduces the deformation and bending moment values in the critical regions of pipes. As a result of reinforcement in the mid-point of the pipe defined as the most critical region, 52% and 36% less deformation was observed in the crown and springlines of the pipe, respectively. In addition, the bending moment values for the same critical section were determined to be 40% less in the crown and 28% less in the springline regions of the pipe.

• Journal of the Korean Society of Safety
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• v.37 no.4
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• pp.36-43
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• 2022

Generally, in construction sites, the pipe support installation workers often use support pins of 9~10 mm which are much smaller than the safety standard sizes for work convenience. Although the safety certification standard thickness of the support pins is 11 mm, and the supervisors are often indifferent to this. Hence, products with far lower performance than the pipe support safety certification value of 40,000 N, which is applied in the supporting post-structural review, are used. Accordingly, this acts as a factor causing collapse accidents in the process of pouring concrete at the construction site. Therefore, this study performed compression experiments on new and reused pipe supports to determine how the thickness of the support pins affects the structural compression performance of the pipe support by considering the thickness of the support pins as a critical variable among various factors affecting the pipe support performance. In the course of the study, the compression test of the pipe support (V2, V4) for the new products showed that only 14 (58.3%) of the total 24 samples satisfied the safety certification standard value of 40,000 N, which indicates that more thorough quality control is required in the manufacturing process. Additionally, comparing the thickness of the support pins and their fracture shape shows that the pipes with support length of 4.0 m or longer are much more affected by the buckling of the entire length than the thickness of the support pins. Of the several factors affecting the performance of reused pipe supports, it was found that, similar to the new products, the use of support pins, with thickness of 12 mm rather than 11 mm, can satisfy the safety certification value more appropriately. Therefore, regardless of the state of usage, it could be concluded that it is necessary to use 12 mm products, whose thickness is larger than that of the safety certification standard value of 11 mm, to improve the performance of the pipe supports.