• Journal of the Korean Society of Safety
• /
• v.32 no.4
• /
• pp.129-136
• /
• 2017

This study investigated the probability of possible accident through qualitative and quantitative analysis of the pressure safety valve types installed in facilities using high pressure gas to compare the installation domestic and foreign pressure safety valve standards sought the safety characteristics and safety improvement direction accordingly. The three types are the case where the shut-off valve is not installed at the front of the PSV (Case A), If a shut-off valve is installed at the front of the PSV for inspection (Case B) and If a shut-off valve is installed in front of PSV (C.S.O), PSV is installed in parallel (Case C). Three types of cases were compared with FTA and HAZOP. The results of study of the possible accidents due to over-pressure safety valve installation type, used in a high-pressure gas facilities was shows in the following order Case B > Case A > Case C. The results of analysis through FTA was in order to protect the reservoir for the possible occurring of accident the safety valve installation is depend on its type. In the FTA analysis, defects in the device itself which attached to the storage tank as a substitute for analysis of the probability of operator mistakes was Case B with as high as $2.01{\times}10^{-6}$. Depending on the type of installation analysis of Case B in order to ensure safety is prohibited to install shut-off valve and believes that mandatory regulations are needed. Rationally installing of pressure safety valve in the high pressure using facilities will be expected to improve the industrial safety from severe accidents such as high-pressure gas fire explosion.

• Journal of the Korean Institute of Gas
• /
• v.9 no.3 s.28
• /
• pp.44-48
• /
• 2005

Experimental works were carried out to evaluate the service life of low pressure LPG regulators for domestic use. Experimental results showed that the operating pressure of regulators used for 7 years notably deviated from the standard value of the adjusting pressure and the lock-up pressure. Thus, it is estimated that low pressure LPG regulators have approximately 6 years of service life.

• Safety and Health at Work
• /
• v.7 no.4
• /
• pp.340-346
• /
• 2016

Background: safety and healthy working environment has received numerous research attention over the years. Majority of these researches seem to have been conducted in the construction industry, with little attention in the health sector. Nonetheless, there are couple of studies conducted in Africa that suggest pressure in hospitals. Therefore the aim of the study was to examine how pressure influence safety behavior in the hospitals. With reference to the relevance of safety behavior in primary health care delivery, there was the need for the study. Method: Data was obtained from 422 public hospital employees. Respondents were assured that all information would be kept confidential to increase the response rate and acquire more accurate information. Collection of questionnaires from participants took four weeks (20 working days), after which the data was analyzed. Results: The result of the study showed that work pressure correlated negatively with safety behavior. General safety climate significantly correlated positively with safety behavior and negatively with work pressure, although the effect size for the latter was smaller. Hierarchical regression analysis showed management commitment to safety to moderate the relationship between work pressure and safety behavior. Conclusion: When employees perceive safety communication, safety systems and training to be positive, they seem to comply with safety rules and procedures than voluntarily participate in safety activities.

• Journal of the Korean Society of Safety
• /
• v.13 no.2
• /
• pp.104-108
• /
• 1998

In order to evaluate the performances of safety valves for low pressure, the popping pressure and flow rate of the natural gas have been investigated. The measured results of the popping pressure show that there is a big scattering depending on the manufacture year of a safety valve. And sample A showed the ideal popping pressure mode compared to other B and C samples. The popping flow rate of the safety valve is proportional to the seat size as the inlet pressure increases. These results may be used as a guideline for a design and diagnosis of the safety valve.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.12
• /
• pp.729-734
• /
• 2017

A safety relief valve is a device that relieves excessive pressure in piping lines or tanks and maintains pressure at the appropriate pressure level for use. The (pressure in the) safety valve is directly influenced by the change in the back pressure, depending on whether the vents in the spring bonnet are vented to the atmosphere or to the outlet. The back pressure is divided into the built-up back pressure and the superimposed back pressure, and the back pressure characteristics vary according to the usage conditions. The safety valve used in this study is a Conventional Safety Relief Valve. The blowdown of the safety valve is predicted by establishing the equilibrium equation between the opening force and spring force considering the back pressure characteristics. Its reliability is secured by using CFX17.1. In addition, the safety of the safety valve trim was examined through fluid-structure interaction analysis.

• Journal of the Korean Society of Safety
• /
• v.25 no.5
• /
• pp.7-14
• /
• 2010

Ultra high pressure system, which can be generally increased over 1,000bar, needs to have sealing mechanism to protect leakage and selection of the materials used in the intensifier. Components such as pressure vessel, hydraulic hose assembly, accumulator, hydraulic cylinder, hydraulic valve, pipe, etc., are tested under the impulse-pressure conditions. Components need to be tested under 1.5 to 3 times of rated pressure to check the tolerance even though rated pressure range of these components are not ultra high pressure. So, the ultra high pressure system needs to be equiped to test components. In this study, safety assessments of ultra high pressure system which are using failure analysis of components, changing the types of the control system, and finite element analysis with static condition, are investigated.

• Journal of the Korean Institute of Gas
• /
• v.18 no.6
• /
• pp.40-44
• /
• 2014

In this study, it is analyzed that a change in the shape of small propane containers made of STS304 when increasing of internal pressure. When internal pressure of a small propane container increased, bottom of end plate is convexly changed. This test is applied to a water bath pressure test to analyze the characteristics of the container. Water bath is able to analyze relationship between internal pressure and volume. In result, shape change section is confirmed because bottom of end plate is convexly changed. In addition, this section tend to decrease internal pressure because a volume increment increase out of proportion to pressure. The results of this study are expected to contribute to improving the safety of the pressure vessel, as well as various small propane container.

• Journal of the Korean Institute of Gas
• /
• v.21 no.6
• /
• pp.15-22
• /
• 2017

The pressure safety valve is very important device for securing the safety in the facilities which is operated by high pressure gases. The performance test should be periodically inspected by relate law because the failure of pressure safety valves might be main causes of serious accidents in the industrial fields. Shop test is mainly use for inspecting the performance test of pressure safety valves but the test method is not to be a solution for securing the safety. So, the development of alternative method is required. In this paper, there is a limit to securing the safety if the performance test is with just shop test. The limitation is checked from analysis result based on performance test results of pressure safety valves. The necessity for introducing the in-service test is reviewed to surmount the limitation. As a result, in-service test method should be developed and introduced to improve the inspection efficiency and economical loss. Also, it can be reduce the risk level.

• The KSFM Journal of Fluid Machinery
• /
• v.10 no.5
• /
• pp.20-26
• /
• 2007

Some gate valves are susceptible to pressure locking and thermal binding which prevent the safety function. The safety related gate valves susceptible to pressure locking and thermal binding shall be identified and taken preventive actions to ensure the safety function. The identification of the gate valves susceptible to pressure locking and thermal binding needs the evaluation of system design, valve and piping arrangement, test requirements, and operating conditions. Application of preventive methods should consider the system safety function, applicability, effectiveness, interface with system design, and cost. The selection procedure of valves susceptible to pressure locking and thermal binding can be effectively used in industry including nuclear power plants. In order to prevent the pressure locking, the hole can be drilled through the one disc of upstream side or down stream and the external equalizing line can be installed from bonnet to downstream or upstream. The double disc parallel seat valve type can be used instead of flexible wedge gate valve to prevent the thermal binding. The identification of gate valves susceptible to pressure locking and thermal binding, and preventive actions will meet the regulatory requirements and enhance the availability and safety of plants.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.629-636
• /
• 2003

The purpose of this study is localization of safety relief valves for Nuclear Service through technical development with overall design, fabrication, inspection, capacity certification test and functional qualification test of safety relief valves in accordance with ASME Section III and KEPIC Code. Safety relief valve is the important equipment used to protect the pressure vessel, the steam generator and the other pressure facility from overpressure by discharging the operating medium when the pressure of system is reaching the design pressure of the system. But we're depending on technology of the other country up to the present time. Because we don‘ have our own technologies, we have been spent the great time and money on installing and repairing safety relief valve at nuclear power plant. Therefore we have to achieve the development of safety relief valves for Nuclear Service with our own technologies.