The multichamber device belongs to pulsed methods of forming and is mainly intended for use in small-scale production. The process of forming is carried out under pressure of an elastic disk due to kinetic energy of the piston accumulated throughout the working cycle. The piston is accelerated under pressure of high-temperature gas, which is formed in the combustion chamber during the combustion of gaseous fuel mixes. The paper suggests design modifications of the existing device in order to expand its technological potential by increasing the kinetic energy of the piston. This is achieved due to end-to-end channel in the elastic disk and the piston connecting a head-end volume of the working cylinder with the combustion chamber, where the backpressure valve is installed at the end of the channel on the side of the combustion chamber. Keywordssheet forming, elastic medium, gas forming, kinetic energy, backpressure valve, multichamber device, fuel mix, gas pressureInternational Symposium on Engineering and Earth Sciences (ISEES 2018)