• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.370-373
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• 2009

The runner-valve is an effective solution for the filling balance of the multi cavity molds. Automation of the runner-valve system is necessary for more efficient and accurate control of the filing balance. We designed an automatic runner-valve actuator for the automation and characterized the actuator by experiment. We obtained a linear relationship between motor-driving time and the height of the runner-valve. However, the motor-driving times for upward and downward directions were different due to the frictional characteristics of the actuators. Also we obtained the motor-driving times for backlashes of the 4 actuators. The results were used to formulate the relationship between the resin-arrival time and the flow rate change of the runner-valve with the theoretical equation that was derived in the previous research.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.854-856
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• 2011

A vent relief valve for oxidizer tank has been designed for liquid propellant feeding system of the space launch vehicle. The vent relief valve ensures oxidizer tank ventilation during filling and its protection from overpressure after filling. Tank ventilation during filling is ensured by vent valve and tank protection is ensured by combined operation of relief valve and vent valve. Numerical analysis predicted that pneumatic behavior and dynamic characteristics met the valve requirements. After manufacturing the prototype model, we have been conducting the tests to evaluate the performance of the vent relief valve.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.57-64
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• 2017

Today, due to the environmental regulations regarding air pollution in the EU, the use of EPS (Styrofoam) as the cushioning material in the packaging industry is decreasing. In effect, air cushioning based cushioning materials are rapidly expanding into the market and replacing EPS, due to their excellent buffering ability and environmental friendliness. This is a new selective filling type air filling material manufacturing technology that affords improvements in the amount of raw materials required, its processing and its aesthetic appearance compared to the conventional air filling cushioning materials. In this study, a multi-stage air cell filling valve molding technology is developed based on selective filling technology, which allows packages to be selectively filled in various forms by applying valve forming structure technology. This multi-stage air cell filling valve molding technology is a technique in which a plurality of injection ports are formed by laminating three layers of films, viz. a first injection film, a valve film, and a second injection film having valve ends. In the conventional technology, a separate external air injection path for injecting air into a plurality of connected air bags is needed. However, in the proposed system, an external air injection path is formed inside the air bag, Due to the lack of need for an injection furnace, the raw material and process are reduced and air is injected and then discharged, while the air bag is reduced in length to 63 ~ 66% of its normal value. The outer surface of the outer air injection path is integrated inside by maintaining the original length of the cross section, while the unnecessary folded air is injected into the interior of the air bag, This smart air filling type cushioning material manufacturing technology constitutes a big improvement over the existing technologies.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.73-79
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• 2012

Currently, all domestic CNG vehicles have manual cylinder valves installed. These are inconvenient for drivers in case of a gas leak accident, because drivers have to stop the vehicle operation and manually close the valve. It makes difficult condition for drivers to quickly and properly respond to such accidents. In advanced European countries, they require Automatic cylinder valve installation, which has a structure where the valve is automatically shut off when the driver turns off the ignition in case of a gas leak. If this electric valve system is introduced in Korea, the safety of CNG buses will be improved with better functionalities. In this paper, in order to solve the structural problem of difficulty for a driver to identify the operational status of individual Automatic cylinder valves, an approach was made regarding temperature increase with pressure increase during CNG filling. it was estimated that the temperature increased approximately more than $30^{\circ}C$ due to pressure difference during the filling. Therefore, it was concluded from the experimental data that the valve of the container whose temperature did not increase did not operate, resulting in filling failure.

• Journal of the Korean Institute of Gas
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• v.27 no.1
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• pp.38-47
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• 2023

In the hydrogen filling process, hydrogen flows by the pressure difference between the supply pressure at a filling station and a storage tank in the vehicle, and the flow rate depends on the pressure difference. Therefore, it is essential to consider the pressure drop of hydrogen occurring during the filling process, and the efficiency of the hydrogen filling process can be improved through its analysis. In this study, the pressure drop was analyzed for a hose, a nozzle/receptacle coupling, a pipe, and a valve in a filling line. The pressure drops through hose and pipe, the nozzle,receptacle coupling, and the valve were calculated by using a equation for a straight conduit, a flow nozzle formula, and a gas flow respectively. In addition, as a result of comprehensive analysis of the pressure drop effect occurring in each component, it was found that the factor that has the greatest influence on the pressure drop in the entire filling line is the pressure drop through the valve. This study can be used to develop a model of the hydrogen filling process by analyzing hydrogen flow including hydrogen filling in the future.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.288-293
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• 2001

This paper presents the water-hammer effect due to the rapid opening and closing of isolation valve and thruster valve in the spacecraft propulsion system. The single propellant feed system was modeled to investigate the maximum peak pressure due to the water-hammer effect. The test parameters are tank supply pressure, shape and throat length of orifice and line length. Kerosene was used as the inert simulant propellant liquid instead of hydrazine. As downstream line length after isolation valve increased from 1.5 to 2.5m, the maximum line-filling water-hammer peak pressure decreased, but the average time interval between peak pressures increased. The maximum line-filling water-hammer peak pressure with orifice was lower than without orifice, and the maximum line-filling water-hammer peak pressure with orifice at the back of isolation valve was lower than with orifice in front of isolation valve. Without orifice, the maximum water-hammer peak pressure due to the rapid opening and closing of the thruster valve was about 126% of tank supply pressure. With orifice, it decreased. As orifice throat length increased, it decreased. The maximum water-hammer peak pressure due to the rapid closing of the thruster valve with converging-diverging orifice was lower than normal orifice. It was found that the orifice as a means of pressure drop was very effective to reduce the water hammer peak pressure at the thruster valve. The results of this study can be used for the design of spacecraft liquid propulsion feed system.

• Current Industrial and Technological Trends in Aerospace
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• v.9 no.1
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• pp.130-138
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• 2011

A vent relief valve performs as a safety valve, which ensures ventilation of propellant tank during filling and protection from tank overpressure after filling. Because of the reliability and cost saving, the virtually same vent relief valve has been used on all US cryogenic liquid fueled launch vehicles. Some modification to the valve has been applied to satisfy the various mission requirements of launch vehicles. This paper reviews the main technology trends of the vent relief valve applied to the propellant feed system for launch vehicle with respect to design and manufacture. This paper also introduces the operating technology of vent relief valve applied for launch vehicles of advanced countries in space development.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.415-418
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• 1999

The characteristics of VRLA (valve regulated Iead-acid) battery with the tubular positive plate and gel type electrolyte were examined as a function of active material filling density. The filling density of positive plate was 3.2 g/mL, 3.4 g/mL, and 3.6 g/mL, respectively. These VRLA batteries were cycled with 100% DOD (depth of discharge) at the $C_5/5$ rate, followed by IU-type recharge with $I_{max}=0.2C_{10}/10$ and a final voltage V=2.40 V/cell. The test was performed in a thermostatic room at $25{\pm}1^{\circ}C$. The result indicated that the initial capacity was independent of active material filling density, i.e., the highest initial capacity was 3.4 g/mL of filling density and the lowest was 3.6 g/mL. On aspect of the cycle-life performance of the VRLA battery, the filling density of 3.6 g/mL was similar to that of 3.4 g/mL in the positive plate, and both were higher than that of 3.2 g/mL. Water-loss and degradation of the VRLA battery were decreased according to an increase of the filling density in the positive plate. The optimum filling density of the active material was 3.4~3.6 g/mL.

• Journal of the Korean Society of Visualization
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• v.4 no.1
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• pp.47-55
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• 2006

The left ventricular filling flow is now considered as an indicator which can be used for early diagnosing of cardiovascular diseases. Because the understanding of left ventricular flow physics is critical for this purpose, the downstream flow characteristics of the artificial heart valve are investigated using particle image velocimetry (PIV) method. In this study, we investigated the wake characteristics of flows passing through three different artificial valves (St.Jude medical bileaflet mechanical valve. Bjork-Shiley monostrut mechanical valve and St.Jude medical Biocor bio valve). The downstream flow field has remarkably altered according to the different valves. SJM MHV has the flow field similar to the pulsating circular jet and BS MHV has oblique pulsating jet. SJM BHV shows the similar flow field of clinical data of normal heart.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.164-167
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• 2003

In generally, Gas fill & drain valve is used in filling Gases to tank on high pressure in launcher The valve is quick coupling type and is separated by manual or remote control. In KSR-III, He gas fill & drain valve separated by remote control is used. In this paper, that are explained about the design specification, the test procedure, the autonomous test result and the flight test result.