When the pressure at a weak spot established at a certain part of a high pressure vessel or piping system exceeds a design pressure, this weak spot bursts, and the pressurized gas emitted through the weak spot generates a compression wave system at the downstream of the disc. In this connection, an experimental study was performed by using a shock tube facility with dimensional analysis to relate the valve opening time and shock wave formation distance with the diaphragm radius of curvature, the pressure ratio and depth of cross type groove. Four kinds of curvature radii were used with and without $90^{circ}$ groove. It was found that the smaller the radius of curvature of the rupture disc is, the thinner the thickness of the rupture disc is; and the smaller the ultimate strength of the rupture disc is, the shorter the valve opening time becomes. The radius of curvature and the ultimate strength of the rupture disc for the same conditions are smaller; the maximum pressure rise caused by the coalescences of the compression wave at the downstream of the valve is smaller. Finally, we found that the formation distance of the shock wave for the case of smaller curvature is longer than that for the case of a larger one because of the retardation of accumulation of the compression wave.