Solenoid-actuated pressure-reducing valves are commonly used in hydraulic machinery. Most studies on solenoid-actuated pressure control devices are focused on the electrical input signals or on the control techniques for the solenoid valves, but no study has been done that determines the influence of the design parameters on the valve’s output. Before designing a controller, it is imperative to know the valve’s performance by determining the significance of each valve parameter. In this study, established physical laws from fluid dynamics and mechanics are used to build a model that is solved using the ODE 45 solver of Simulink in the time domain. The actuating force, up to 15 N, exerted on the spool and the inlet pressure, ranging from 50 to 80 bar, are obtained through experimentation. It is found that the output pressure fluctuates significantly if the outlet is blocked, while at the fully opened outlet condition, a flow rate of 12 (L/min) was obtained. A pin diameter of 2.15 mm enables us to vary the output pressure between 0 and 41 bar. We found that higher inlet pressure leads to lower output pressure as the outlet is opened. No linearization of the actual mathematical model is performed, which makes the study unique.

Dehumidification in the pneumatic system is an important factor for preventing efficiency decrease and malfunction due to humid air. Various dehumidifiers have been developed until now and especially dehumidifiers using polymer membrane have been studied for low cost and easy manufacture. In this study, experiments and flow analysis of hollow fiber membrane module were performed for confirming the efficiency of dehumidification which is also related to the pneumatic system performance improvement. Water removal ability and adsorption performance of hollow fiber membrane module were confirmed by results of flow analysis and experiments, and the reliability of the flow analysis could be obtained through the comparison with experiment results. From this study, dehumidification phenomena in the hollow fiber membrane module were found out, and the basic design concept for the next generation dehumidification system was also discussed.