• Journal of the Korean Institute of Gas
• /
• v.22 no.6
• /
• pp.104-108
• /
• 2018

Experimental studies have been done to examine the aging characteristics by regulator diaphragms of gas pressure, governor room of city gas. Various testing samples with different service periods were manufactured. The results of SEM observation indicated that the surface and thickness of the samples tested were slightly sensitive to the service periods. It was found that as the service periods increased, the tensile strength of diaphragm samples decreased. For samples over 25 years of service, the strength decreased to approximately 60 % of that of new diaphragms. It was also found that as the service periods increased, the elongation increased.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.10
• /
• pp.5980-5987
• /
• 2014

As a response to exhaust gas regulations, the electronic control system was applied to the diesel engine. The injected fuel mass and injection timing are accurately controlled using it, and the fuel efficiency and the engine output are significantly increased. In addition, the noise and the vibration of vehicles are decreased. To maintain the optimal performance of an electronic control diesel engine, it is important to control the fuel injection pressure accurately using the fuel pressure regulator. When the fuel pressure regulator is not worked normally, the failure phenomena (starting failure, staring delay, accelerated failure, engine mismatch et al.) occurred because the fuel pressure is not stabilized and controlled accurately. In this study, the effects on a fuel pressure, return fuel mass flow, and engine rotating speed according to the control rate of fuel pressure regulator were investigated to analyze the performance variation under the failure conditions of a fuel pressure regulator. As a result, when the control rate of a fuel pressure regulator decreased by 4%~6% compared to that of the standard condition, the variation of engine rotating speed and return fuel flow were increased greatly, and the abnormal condition occurred. In addition, it is possible to diagnose the failure of a fuel pressure regulator by monitoring these conditions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2012.05a
• /
• pp.443-446
• /
• 2012

A thrust control valve of a liquid rocket engine plays a role to increase or decrease the thrust of an LRE by modulating the flow rate of propellant into a gas-generator. This paper deals with a flow regulator that has functions of not only modulating thrust but also maintaining constant flow rate regardless of pressure change at inlet or outlet of the flow regulator. A direct acting flow regulator was fabricated and tested for the comparison of experimental and simulation results under steady-state conditions. The drawbacks and limitations of the flow regulator were analyzed. Also the new design of a flow regulator was proposed.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.6 no.4
• /
• pp.47-58
• /
• 2002

The pressure regulator has been developed as a pressure-control device of propellant tank in KSR-III. The pressurization system of KSR-III is a basic pressurization system composed of pressurant, He tank and propellant tank. The pressure-control regulator is the most important part of gas-pressurized feed system along with He tank, pyrovalve and He fill valve. The first model of the regulator is tested to satisfy in leakage, strength and basic performance. The second model is tested in the overall test of the KSR-III propulsion system using water. From the test result of the second model, we conclude that the capacity of valve(Cv) must be increased in real system. The third model is modified and tested in the overall test of KSR-III propulsion system using propellant. Finally, the pressure-control regulator is qualified from firing test.

• Journal of the Korean Institute of Gas
• /
• v.26 no.5
• /
• pp.35-40
• /
• 2022

PCVD (Plasma Chemical Vapor Deposition), a solar cell manufacturing facility, is a facility that deposits plasma generated in a chamber (NH₃, SIH₄, O₂ on a wafer. In the PCVD facility, gas movement and injection is performed in the gas cabinet, and there are many leak points inside because MFC, regulator, valve, pipe, etc. are intricately connected. In order to prevent explosion in case of leakage of NH₃ with an upper explosive limit (UEL) of 33.6% and a lower explosive limit (LEL) of 15%, the dilution capacity must be capable of allowing the concentration of NH₃ to be out of the explosive range. This study was analyzed using the CFD analysis technique, which can confirm the dilution ability in 3D and numerical values when NH₃ gas leaks from the existing PCVD gas cabinet. As a result, it was concluded that it corresponds to medium dilution and that testicular ventilation is possible through facility improvement.

• Journal of the Korean Institute of Gas
• /
• v.11 no.4
• /
• pp.12-16
• /
• 2007

The fuel pressure regulator mounted on CNG vehicles is used to maintain a constant pressure in the fuel injection system. It needs precise fuel pressure control to obtain benefits of high efficiency and low emissions in CNG vehicles. In this study, a high pressure test rig for the performance evaluation of CNG regulators was introduced. Two different CNG regulators were tested and compared each other at various test conditions. Results showed that dynamic response and creep characteristics are directly effected by the valve assembly design. Gas temperature was dramatically dropped at hish supply pressure conditions, so that effective design for coolant bowl is needed to prevent icing problem.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.3
• /
• pp.1677-1683
• /
• 2015

To cope with exhaust gas regulation, Diesel engine applied to electronic control system. As it accurately regulated the injected fuel mass and the fuel efficiency and the output are increased but the noise and the vibration are decreased. In order to keep the performance of Electronic Diesel Control System, it is important to accurately control the fuel pressure. However, when the regulator of fuel pressure is not controlled properly, the failure phenomenons(starting failure, staring delay, accelerated failure, engine mismatch et al.) occur because the fuel pressure is not stabilize. In this study, effects on a fuel pressure, engine rotating speed according to the control rate of fuel-pressure regulator are investigated in order to analyzed the performance variation with failure of fuel-pressure regulator. As a result, when the control rate of a fuel-pressure regulator is 4%~6% lower than that of standard condition, the variation of engine's rpm and return fuel flow is increased, and the abnormal condition was occurred. Besides, it is possible to diagnose the failures on fuel-pressure regulator under these conditions.

• Journal of the Korean Institute of Gas
• /
• v.17 no.3
• /
• pp.8-13
• /
• 2013

The purpose of this paper is to study for fire example by fuel leakage in LPG Vehicle. At first example, the car was repaired the fuel line that was connected with pressure hose between fuel regulator and injector in engine. But the service man was not very tighten with regular torque. At a result, the gas leaked on hot parts of engine. It verified the production of fire by engine heat. At second example, when the repair man, after replacement the injector, inserted the injector in a assembling part of it, he didn't the transform condition of fixing part. Therefore, the tearing phenomenon of O ring producted the controlled leakage of fuel by the injector deflection. It found the fact that the fuel leaked with gap of O ring. At third example. the fuel-cut solenoid valve was lined with pressure regulator unit. But the service man didn't throughly certify the leaked work of connected parts after repaired it. As a result, it certified the fire by engine heating leaked liquefied petroleum gas. Therefore it have to minimize the fire production that the driver should do no problem to throughly manage the fuel system.

• 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.

• Journal of Mechanical Science and Technology
• /
• v.20 no.3
• /
• pp.329-334
• /
• 2006

This paper presents the evaluation of LPG (Liquefied petroleum gas) regulators for home use. For the evaluation, several properties of the regulators were experimentally analyzed, such as the operation of safety device, the adjusting and lock-up pressure, the adjusting spring and the diaphragm, with respect to the used time of the regulators. Experimental results showed that the initial operation performances of regulators were degraded with increase of the service time and also showed that the degradation of the performance and material property could become serious after about six-year-use of the regulators.