the vacuum unit is designed to generate an elevated vacuum between user’s liner and the socket to prevent pistoning movement and grip the stump firmly. To do this, there should be a sealed environment between user’s liner and the socket. Once the environment is sealed, which is compressed and released during normal walking, the vacuum unit draws air from the socket through one-way valves and evacuates it through the pump. So vacuum unit, discharges the air in this sealed environment on every step of user. After multiple steps of the user, 15 in.Hg ( around 0.5 bar ) is created in the sealed socket environment.
