Space launch vehicle has various separation systems such as linear-shaped charge devices, severance of the structure using pyro expanding tube and pyro-actuated collet release device. This paper highlights the analysis and the testing of a pyro expanding tube type separation frame utilized in the stage separation of launch vehicles. Separation frames are made of Al7075-T651 plate material. Separation frame endure the applied structural load and easily severed by pyro expanding tube at a low level of pyroshock. Under detonation effect, a pressure shock wave is induced in the walls of pyro expanding tube. This rapid expansion of the pyro expanding tube subsequently induces a shock wave in the outer walls of separation frame. The shock wave induces sufficient stresses in the edge of separation frame due to the bending of these outer walls. This paper presents the analysis of the separation frame which sustains high structural loads and severance test of separation frames. Analysis was conducted by ANSYS and AUTODYN. Separation frames satisfy the required strength and severance performance. Pyroshock of separation frame is compared with the pyroshock of pyrotechnic devices.