Vent Valve for Test Launch Vehicle of Korea Space Launch Vehicle II

The performance of a vent valve with a spring-loaded door is evaluated for the test launch vehicle of Korea Space Launch Vehicle II. Twelve vent valves are manufactured for the three compartments of the test launch vehicle. The structural robustness of the vent valves is evaluated via random vibration tests of . All the vent valves properly operate even after the vibration tests. The flow characteristics of the vent valves are investigated via flow tests. The cracking pressure of the vent valves is 431–514 Pa. The flow area of the vent valves is calculated from the test results, and two models for the valves for the venting analysis are determined on the basis of the flow area. The pressure difference between inside and outside the compartments and the pressure drop rate in the compartments during flight are predicted via a venting analysis. The maximum values of the pressure difference are and 7.30 kPa. The maximum pressure drop rate is . The maximum pressure difference in the test launch vehicle is much lower than that in Korea Space Launch Vehicle I measured in the first flight test, and the maximum pressure drop rate of the test launch vehicle is similar to that of Korea Space Launch Vehicle I. Consequently, the vent valve with a spring-loaded door is suitable for the test launch vehicle.