The floor-mounted pneumatic clamp, by firmly securing the tank, allows unscrewing and tightening the valve of any fire extinguisher, both powder and carbon dioxide types, as well as automatic fire suppression systems. The clamping force is adjustable and visible through the pressure regulator equipped with a condensate recovery system. It is fitted with two operating buttons and an emergency stop button, fully complying with safety regulations. It is also designed for mounting an automatic electric unscrewing/tightening device with electronic control.