Abstract: An inlet valve assembly for a central vacuum system is installed in a wall or floor having a front side, a backside and a mounting hole extending therethrough. This inlet valve assembly includes a front mounting plate having an inlet tube. The assembly also has an annular brace adapted to slidably mount on the inlet tube and sized to fit through the mounting hole. The assembly also has a plurality of clamping arms pivotally mounted on the brace. These arms can swing from a retracted position alongside the brace to an extended position at the backside.